Desulphation of lead acid batteries is a bit more complicated than just passing current pulses to break up the sulphate crystals. First the battery needs to be emptied and washed to remove any sediment. Next the acid is replaced with new solution mixed to the correct specific gravity. The desulphation charge and pulse cycle is run through a couple of times until the two sets of plates are visibly different in colour when charged. The battery is then drained and cleaned once more before being filled with new acid. The capacity will never be as good as the original specifications but it can be used in an emergency situation to get out trouble if there is no alternative. The rejuvenated batteries will last for perhaps a year before replacement is absolutely necessary. This procedure was used for the emergency battery systems on merchant navy ships where the ships might be away in remote areas of the world for a couple of years before returning to civilisation where new batteries could be obtained. Not a trivial process and very time consuming and labour intensive to carry out properly. The other disadvantage is that any clothes worn when carrying out such battery maintenance dissolves into a mass of holes due to the effects of acid and the acidic vapour.
Yep can confirm. Old dude who has garage next to mine does it. He buys old batteries for 5euros washes them with different liquid and some other stuff and does revive them to sell after for 20 euros. Considering that he has to buy new acid and the time he sinks in I keep telling he is an idiot.
"The other disadvantage is that any clothes worn when carrying out such battery maintenance dissolves into a mass of holes due to the effects of acid and the acidic vapour." Jebus dude, wear PPE and get a fume hood when working with acids and strong chemicals. lol
Thanks for sharing this, I didn't know about it. 🙂 I see the potential in emergencies, but thinking about it, the procedure is reaching towards fixing a broken hammer by replacing the handle. If that doesn't help then the head, too. Same goes for the battery; if the plates are also replaced (assuming the container is not aged/damaged), we got a new battery... Considering the necessary labour, the involved hazards, potential pollution etc you mentioned, it seems full recycle is the way to go for good reasons. Mind you, I'm not arguing, just saying, it's probably explaining a lot on how and why things go towards full recycling. Thanks again for sharing this interesting aspect.
@@greatscottlab Your next project. Get a 36 amp battery connect it to a ups or 150 watt inverter but ups is better. Do a stress test on it and charge it with the 500 watt ups. I have a dell laptop the battery is very expensive. I'm not ready to shell for the new one but a 12v 36a battery is cheaper than the dell battery.
i want to see the real time tracking sheet ;) it’s not 30 days 1 video. but this video spans of 30 days. how much of the 30 days is actually this video?
I've always found battery 'rejuvenation' to be no more than folly. If I have a battery that is not doing the job I need it to do, I recycle and replace. Nothing promotes peace-of-mind like a brand new battery. Thanks for the video!
NiCd are actually fairly amenable to being restored if they have suffered from the famous memory effect and i have seen wonky NiMH come back to reasonable life as well under some circumstances, i do believe there is a circumstance under which a sort of layer can form which locks away a part of capacity that is not otherwise chemically damaged. But this is an exception rather than a rule and i don't necessarily see that other battery chemistries would work like that; and anyway prevention from a reasonable usage pattern for sure has to be better than any attempt at a cure, and when it's done, it's done, they aren't gonna live forever.
actually, I saw a video the other month where some guy who sells batterys tested a few of the machines on the market on different type of errors on car-batterys. He could actually save 2 of the batterys, but most of the devices did not work :)
Yeah but you can't blame people for wanting to try! Those batteries are expensive, and we all use electricity... so logically we think maybe save money, maybe store power, but... yeah. Maybe rebuilding is the way to go if you have 3 or more batteries, because I've heard many times that usually only one cell is bad, which causes high internal resistance and the battery can never reach full voltage (about 1.5 volts per plate, 3 volts per cell?) For example i have several batteries and a few cannot charge up to full one sits at around 11 volts after charge, meaning it has a bad cell. Get 2 or more batteries and combine the good cells into a rebuilt battery and you get a battery that works but still has some diminished capacity. Better would be to learn how to replate the plates, with electricity. Isn't that how they make them in the first place? Think of it this way, when you apply current to solution, water splits into H and O... the anode (+) (O-) is made there, meaning if you took a grid of wires and put it in the right solution containing lead ions, and connect to the (-) it would plate lead all over the grid. Then you just reverse it and then the thing will have oxygen generated directly on the lead, causing it to turn in to lead oxide?
@@simonlinser8286 "You can't blame people for wanting to try" specifically makes it a super fertile ground for outright scams and in general overblown claims of efficacy and safety (often but not always for malicious reasons), and you have to stay sceptical due to this. And if you leave yourself room for error, you better err on the side of not supporting scams. Which on the other hand shouldn't hold you back from trying to better the world and reduce waste but with the requisite effort and rigour at hand.
The electrochemistry of a desulfator is solid, but often the reason capacities drop in lead acid batteries is more from "shedding": lead sulfate is less dense than lead metal, and like ice forcing against the walls of water bottle in the freezer, it can force the lead metal apart from the plate (or force itself off of the plate). This is very common in high current ignition batteries, which use a lead sponge matrix instead of a plate. Desulfators work for a very specific failure mode, but way more often the battery is simply permanently damaged by the formation of large sulfate crystals that either fall off the plate or force the plate apart. In these cases, the desulfator will do nothing more than cause a bit of hydrolysis in the electrolyte with each pulse. Obligatory "desulfation works only at full charge" because otherwise the electrons you're pushing into the cell will only be used for the usual lead-acid electrochemistry long before any desulfation occurs (the E0 values for converting sulfate to acid are just a tick higher than those needed to convert lead ions to lead metal). If a desulfator is going to work, it will need to be used with a float charge that's enough to keep the battery charged between pulses. It need not be more than what's needed to counter self-discharge, and that's going to vary a lot from battery to battery. And then there's the whole issue of lead oxide generation over the battery's lifetime, which also represents a permanent chemical loss of capacity. Long story short, for 99/100 batteries, recycling and chemical processing are the only ways you can really revive them. For that one out of the bunch that's just not been used in a while, a desulfator could work but needs tuning, special conditions, and constant monitoring to make sure that there's no hydrolysis side reactions.
That is a very awesome explanation of it!!!! The only caveat is that some AGM batteries are built well enough with thick enough fiberglass plates that they can hold together a lot better, even after being obscenely sulphated. I have had good luck with recovering some of the AGM UPS batteries by popping the tops off and slowly adding battery electrolyte and hitting them with 15 volts and a MIG welder
Exactly this. The grey sludge inside a used battery is just lead which has been lost off the plates and had either reduced the size of the plate or is stopping the plate from functioning.
@@astrawally8448 And also sometimes actually shorts out the plates altogether, even. Deep cycle/marine/golf cart/forklift batteries have much thicker plates and that's why they can be discharged to such a low level and be recharged and still function.
Mostly unrelated to the video content, but I noticed when you were showing shots of the PCB layout in Altium that your polygons are overflowing the PCB edge. I was having the same issue and I recently figured out how to fix it. If you duplicate your board outline to the Keep-Out layer, you can assign a rule to have your polygons maintain a specified distance from any Keep-Out layer object, and effectively follow the contour of the Outline. Keep up the great work!
This approach is fine, hovewer, more 'correct' and easier in the long term approach is using BoardOutlineClearance rule under Manufacturing rule set. This way, you will not need to manually update keep-out layer each time you need to redefine board size and/or shape.
The circuit I built is very similar to this. I've tried many different combinations of pulse width, frequency, voltage, and current over the last 10+ years. It has never once revived a battery in any way. It might work for some edge cases but a well cared for battery almost always fails with a dead cell like the first battery shown here (either shorted out or falls apart) and this can not be fixed without rebuilding the whole battery.
Would those edge cases be deep cycle batteries or solid plates used? 🤔 I hope I can find a scientific paper one day that shows it possibly works, or else the products are all a lie.
Only fillable Wet cell batteries if cell has not collapsed can be revived but not using this approach, you need alot higher current and higher voltage to boil it
From what I've had heared - reverse charging is one of the ways to restore battery: First You should discharge the battery to 0, by adding a bulb for a day or so Then you connect charger backwards - positive wire to "-" terminal and the positive one - to "+" terminal, charge up, than again discharge to 0 with a bulb and charge this time correctly. The idea behind this is that sulphotation occurs, I believe, only on anods. By charging the battery backwards - anod and cathod are changing places, so sulphates from anod should dissolve.
I read some on this topic a while ago, and if I remember correctly, the sulfate that is created during normal use is thin, spongy and easily converts back into the electrolyte when charging. Left for too long however, the suflate hardens and does not covert back. The desulfators can in the best case crack this hard layer. This would verify other comments about the process not increasing the capacity (the electrolyte remains weak) but potentially getting an improved current flow (less plate resistance). The pieces nocked off by the process fall to the bottom of the battery where there is a collection chamber. When this fills up and touches the bottom of the plates, the battery is completely toast.
Yeah this seems like one of those things that if you're gonna do it, should be done as part of a regular battery maintenance routine, not something that waits until problems arise, which by then its likely too late.
30 days of strategic planning and implementation in 11 minutes video. As a fellow electronics video creator, i can really appreciate your efforts. Thanks for this lesson Mr. Scott
I would like to see one video where somebody makes a lead acid cell in a glass jar, sulfates it.... And then does various de-sulfurizing circuits with a time lapse camera.
It's great that videos like this one are put up. Too many times someone will put up a video making promises and they turn out to be little more than nonsense and in some cases, a lot of these hacks can be quite dangerous. As a technician, one of my tasks is to physically check the batteries and determine their age. For fire alarm systems and most emergency lighting packs, we recommend strongly that the batteries are to be replaced every six years even if they pass the load test. While they may be recharged to full voltage, they would discharge too rapidly to be of use in an emergency situation and can actually create a hazard. An example of that would be a stairwell that is pitch black due to no lighting when the main power fails and the emergency lighting also fails because the battery is too old.
Lead acid batteries are a bit tricky with their capacites, the 44Ah are messured with a C20 (2.2A) discharge over 20h, if you use a higher Discharge the Capacity is much much lower.
IIRC, at C/10, you get around 70% of the rated AH. Each battery design has its own set of discharge curves. Some of the better SLA batteries I've bought have the discharge curves stenciled right on the side of the battery. I also read in the materials from a battery tester that a good percentage of batteries returned as defective are within specs. This could account for the apparent success of magic circuits.
we test lead acid batteries mostly for load. If it can provide a high load. Like for the start of an engine. That way we know the internal resistance is low. And if we make a full test the capacity isn't far off. Its simpler and quicker to test with a real load. After you sorted the batteries you can still test the true capacity if desired.
All types of battery (not just lead acid) have their capacity measured at some specified load, and capacity invariably dropd at higher loads. The difference with lead acid starter batteries is that they also have a CCA (Cold Cranking Amps) rating as well as capacity, which is a measure of the maximum useful current that battery can supply at -18 Celsius.
@@ferrumignis Car batteries have CCA and CA listed as that should be all they are used for, they are not meant to be discharged more than ~10%. Something like an electric forklift has deep cycle batteries, which spec time at a certain voltage and current.
Thanks for throwing in the issues and fix for the PCB design. I think a lot of people are put off by worrying their boards will not work as intended when they arrive, and as many people have budgetary constraints, find this a show stopper. Being able to diagnose and then repair the design with a workaround means a non-critical design failure is manageable, and you'll learn something along the way too. Dealing with faults and faulty designs is really valuable as a hobbiest, and also if you want to get into component level repair and hacking.
From what my research on these has shown, and using one myself, there is a point of no return for the batteries. If they are lightly sulfated it CAN bring them back to life. But if the battery sat dry, or has an internal short or broken plate no amount of desulfating will revive it. One other thing to keep in mind is while the battery may not have enough juice to start a car, it can still power lower-draw devices in an emergency if you are smart. Granted it is not totally nuked, to begin with.
There is a KNOWN good way to desulfate batteries. Take them to a recycling point, where they will be melted down and processed into new batteries. Jokes aside, I have had limited success with this. It seems that it is very battery dependent. I've saved only a handful with a consumer unit but most go to the "core charge" pile.
Be aware that lead acid batteries specifically has their nominal capacity of say 50 Ah rating under the implied C20 standard; its the capacity if run from full to flat in a duration of 20 hours, so here at 2.5A nominal.
Desulfating does nothing if the electrolyte is depleted. I have recovered many SLAs that were completely dead but they all needed topping up with deionised water. You never get the original capacity back but some got almost 80%. Useless for high drain but great for solar backups, desktop supplies and experimenting. I never used any 'special' desulfating circuitry, holding the the voltage at around 14v to outgas the cells works just fine. This doesn't do anything more than knock the sulphate off the lead plates which exposes the fresh plating and reduces the resistance to allow more charge.
I love this straightforward demonstration of how the circuit does what it claims to in terms of function but does not give the claimed result. Particularly the fact that you highlighted the importance of actually testing the thing that is supposed to be improved (capacity). At the risk of waaay oversimplifying things, rechargeable batteries are going through the equivalent of rusting and then de-rusting. As another commenter pointed out, the starting and ending materials going from charged to discharged and vice versa have different properties, including how much volume they take up. This repetitive process of changing volume leads to mechanical degradation which cannot be reversed with a circuit.
3:14 what you might be experiencing here is actually an internally shorted cell or a cell that's been reverse charged. This can be fixed you'd need to charge it with very high current and pulsing it, essentially kinda damaging it in the process a little. Not the best solution but it does work. Now as for desulfation, I have bought myself a battery desulfator, one of the cheaper kinds. It hasn't actually desulfated anything for me but I noticed it did solve some other problems that those batteries had. Self drainage was gone. on 1 battery the voltage would drop down to 12.5v overtime after fully charging it. Now it stays at 13.2v which is a significant improvement so it isn't entirely useless. What I've found that actually desulfates the battery is by just cycling it with high current. I've even gotten lead acid batteries that were at 0V back to 13.1V with this method and it works really well. You just have to stop discharging the battery at 10.5v to avoid reversing the cells. What you should notice is that the capacity increases with each cycle. It might take time till it starts increasing but you will notice it. From my testing it usually takes around 20 cycles to get it back to a good condition
from nicd charging i remember that they could handle high current charging very well. the output afterwards was better compared to slow charging and they had less memory effects high current charging gargabe cells worked several times.
Any sulphation that such a desulphator circuits can remove can be removed much easier by simply giving the battery a good charge and the occasional "equalisation charge". Those old batteries aren't primarily losing their capacity due to sulphation, but because the plates are slowly falling to bits and losing surface area. When a cell's plates have lost enough material they tend to twist and short together (especially thin plated batteries like automotive starters), or the debris in the bottom of the cell builds up enough to touch the plates and causes much the same effect. That is why you couldn't bring the voltage of the first battery up. It has a shorted cell and is effectively a "10 volt battery" now. Trying to rejuvenate starter batteries is pretty much a waste of time. However bigger deep cycle batteries, such as the ones they use on electric forklifts can be. Their useful period can be extended by increasing the strength of the acid. Of course that actually hastens the ultimate demise of the cells, but more utility is obtained from them during that EOL phase. Also charging the cells to a higher voltage can get a bit more use out of them, but again, trading this for a faster total demise. 12 volt systems can be charged up to between 15.0-15.2 volts. It gives the cell/battery more useful capacity, but it speeds up the degradation of the +ve plate. This can only be done with flooded batteries. Overvolting SLA batteries such as AGM and GEL is not a good idea.
Desulfators do work. I have one and have successfully revived a couple batteries. But it only works if you also add a charger.... In other words u have to charge the battery at the same time you desulfate it. But that was 2 out of 100+ batteries
Yes this is true i thought that myself, it needs to be kept above the knee of the curve for the sulphate to convert back, as you are taking power with the de-sulphator you should be trickling it at the same time.
@@someguy4915 frequency refers to the size of the pulses and listing the frequency of the pulses doesn't make it junk by any measure. An ideal desulfator would have charge frequencies that are all over the map.
Thank you for your technical integrity. So much false information and fake products across the internet. But, it was also the case when all we had was TV, including now. Beware the pharmaceutical industry.
While travelling a lot for work last year, I had to put the batteries of both of my cars on my big battery charger (the kind with wheels) which went into desulfation mode. I thought it did a surprisingly good job and I'm still using the batteries, but I can't say for sure what a charger without a desulfation mode could've done. Now I want to try to get a couple of batteries and experiment with them.
Great video as always. It’s interesting, that I see no comments from any farmers. I was raised on a farm and most farmers had a simple desulfator made from nothing more than a rectifier and a run capacitor from and air conditioning unit. You plug one end into 120 vac and connect the other to the battery. This gives you a DC out with a large AC ripple of 120hz which, over time, breaks down the sulfation. This will not work on batteries with bad cells but will work about 50% of the time. Something to remember though…this simply postpones the inevitable. The sulfation doesn’t magically disappear but falls to the bottom of the cells. Unless the battery is flushed this will eventually cause a problem.
Thanks for debunking this finally, I was wondering if there was a way to possibly revive my 102Ah deep cycle battery. We here in South Africa experience daily power cuts 2 hours, 3x per day (referred to as loadshedding by our power utility that currently can't provide our country with enough electricity). I recently lost a deep cycle 102Ah battery due to this constant charging, discharging cycles in my inverter. The battery is just past one year old. Lithium is better, but unfortunately outside my price range for now. Keep up the good work.
Discharging a Lead Acid battery below 50% on a regular basis will kill it off very quickly. If you are doing this then adding a second battery in parallel will almost certainly more than double the service life. LiFePO4 can be surprisingly cheap if you by the raw cells and add a flying capacitor balancer/BMS. A good cell like the EVE 280AH ones will last around 5000 full cycles where you can discharge down to about 20%. Remember to compress the cells so prevent them bulging under use. This means it is almost twice the usable capacity of a lead acid for a given label AH and if looked after properly will last 10 years or more. Payback is surprisingly quick. I'm off-grid with about 400AH@48V LiFePO4 and love them.
Consider exploring the option of creating your own power storage system using used medical LiFePO4 batteries that will probably have around 80% capacity. This DIY approach could be more affordable and worth considering. LiFePO4 batteries are generally safer and more stable than LiIon batteries, but are less energy-dense. However, they can last up to five times longer and perform better at lower temperatures. It is possible to create a system using inexpensive LiIon scooter batteries as well. A DIY system should cost significantly less than a commercial option. Additionally, having more battery capacity than you need means that each battery capacity will be used less, potentially extending their lifespan. A good BMS should help you set the limits to charge/discharge to prolong them also.
@@AndyFletcherX31 thanx, i'm aware of SLA DoD but our power cuts are so severe, that it's impossible to keep a 50% DoD. I know more batteries will buffer this, but unfortunately batteries are now a commodity in South Africa, making them scarce or very expensive. But I'll explore the options suggested. Thanks
@@Martin4982 I think you should not run heavy duty appliances when the power is off . Fridges, kettles ,vacuum cleaners - these kind of things . I have small pv system but i keep only my computer on it and i fully manage it - the 15 year old 135 AH battery has about half capacity left but is usable only with direct charging
Thsnk you for your video i have been telling people for a long time that there is no simple solution to battery sulphation and that it is not practical for the average person. As usual top notch video from you as always!
I use JLC myself whenever I want a nice board. They do a great job. But the price is never just $2. It could cost just $2 or $4 for the board itself (I think the most I paid was $5), but the shipping can be as much as $15-$20, and I have never received it in a week.
Oh man… I was so happy to see this video and give up to build my “discharger” which was in my mind to “reset” the Pb battery from my alarm system. Now just ordered a new one, thanks you no need to waste more time and energy. Please more Busted videos!
It would be worth checking the composition of the electrolyte in the big battery. Often times the batteries dry out from overcharging and need water added over time.
My first thought too as soon as he brought out that first dead battery; top up the water if it won't hold a charge. Even so-called SLA, just means the electrolyte holes are a bit harder to get to
Thank you for leaving in, explaining and fixing the mistake. It greatly helps to deal with the imposter syndrome in me (and I presume the same applies to many other people). Anyone can make any mistake. The question is, what you do to avoid it the next time and what safeguards you build into your habits in general, based on such experiences. In short: how you learn from it. I _love_ this approach, thank you again.
Hi. Good try. But you need to ad distilled water or (more better) mixture of water and electrolytes (1 to 8 mix). Because your separator inside the battery looks like to "dry" and sulfate crystals won't dissolve.
I just wanted to point out the other person's PCB you stated that R10 is connected to nothing, it is connected to ground, pin 1 IC & led - as per circuit if you check with the multimeter it is connected. Anyway thanks for all the information you are great 👍👍
video's like this are great because you show you have thoroughly tested these things and proven them to be almost worthless. its better to do a video like this than just simply saying it will or wont work
Great! I had one of these circuits on my 'todo list', to recover a few of my dead batteries. It's a bit disappointing to see such dubious results, but at least you just saved me 30 days of dicking around with magic pixie circuits. Thank you, much appreciated! So, perhaps now I'll move to plan 'B' and melt down some of my dead batteries, to harvest the lead.
I have an video idea for you. Convert a lead acid UPC (uninterruptable power supply) to one that uses 18650 Li batteries. Will there be a cost savings? What are the advantages/dis-advantages?
For sure it won't be cost effective hence why we use lead acid instead. Thought your usage may change the overall price. If you often get power lose or/and extended power outrage your lead acid will die faster and depending of how your time is worth/or how critical your infrastructure is, it could be indeed a better alternative. I was reading a litlte about that and using LiFePo4 could be a nice choice instead of the typical lithium ion. Advantage: more recharge cycle than typical Li-ion (and way more than lead acid), also safer. Downside: lower discharge rate than lead-acid (around the same as li-ion i think?) and price :/.
I have seen these little circuits for sale for years, sometimes at high prices. I was always skeptical, but didn't have the time or money to pursue it. THANK YOU, Scott, for debunking this for us, appreciate it very much.
years ago I found a commercial desulfator advertised with great reviews for extending golf cart & forklift battery life. They were not cheap, almost double the price of the deep cycle battery, but at the time I was in need of reliable emergency back up batteries, so I combined them with solar trickle chargers to keep them going unattended for months. 6 months later I needed to call on and use the batteries, only to find everything dead, so dead that they wouldn't revive with a normal charge when I got them back to civilisation. An expensive learning experience.
@@bigbadwolf1966 And did you measure if the trickle charge could keep up and more with the consumption of the desulfator. Seems in your case you simply flattened the battery completely, sitting in that state for while will ensure failure.
The problem is not that lead batteries only sulphate, they can have lots of other faults, such as internal short circuits, interruptions or most commonly one plate simply stops working. If you've seen YT videos where people in more southern countries repair batteries on the street, note that even these skilled craftsmen MUST buy one plate new, I can't remember which one, it CANNOT be recreated in the kitchen/on the street!
Dude i have been following you since the olden days of instructables and i gotta say you have always found a way to make projects so interesting even if they were a gimmic or trivial!
I believe your results. Not sure what's going on with them, either... I can't make sense of why it would drop like that. Hmm... Pretty complicated thing to put together and test for the same amount of time, though.
@@greatscottlab couldn't the capacity dropped even more due to the "stress" of discharging them again in order to measure their capacity, since they were already in bad shape?
I have a "smart" charger from Dunlop,and after some speculating,it's way off desulfating is turning on every 1-2 seconds with it's max charging voltage and the max current (14.8V 1 amp each second or so) It managed to revive 3 of my lead acids that i changed(or added) distilled water in order to refresh the cells. Their capacity more or less refreshed and they were strong enough to not drop their voltages too fast under heavy loads. Although i forgot about them and now at least 2 of those are definitely dead for sure,still gotta try to see what they can do some day
It would be good to see a forklift mechanic's opinion. My old pop used to disulfate and get some good results. Or see what happens if you ran these on the dead battery.
Forklifts have much more durable batteries than a car. The lead plates in a car battery are paper thin and covered in a paste that falls apart. Unless you have a brand new car battery that got sulfated in storage, the possibility of restoring it is near 0. They are just far too delicate. The more often a car battery is drained, the quicker it falls apart internally. It's really only intended to start an engine, or get discharged a small percentage. Forklifts, and batteries designed for renewable energy and deeper discharge are vastly more durable, with golf cart batteries and backup batteries still being better than car batteries. So if there is ever a battery worth attempting to desulfate, it's a forklift battery.
Commercial "desulfators" are typically first and foremost chargers, lead-acid batteries likes to be kept charged, so keeping them charged for a while makes them better for a time compared to not keeping them properly charged. They might also seem much better after a prolonged charging session, as in keeping a higher voltage without load or with insignificant load. But lost capacity is lost capacity.
Very few times I got to make Lead-Acid batteries, that have been through a deep cycle, ever work again. Your results do not surprise me in all honestly. Has anybody though tried to mechanically breakup the crystals? Like with an ultrasonic transducer? I have absolutely no idea if it would work but wouldn´t mind seeing a video on it! :-)
The shed crystals, if you decided to do it this way, would then be permanently excluded from the electrochemical reaction going on in the cells. That would mean a potentially large, permanently lost capacity; but it probably would restore the peak current output. In a pinch it could work, but that battery would need prompt replacement since the drop in capacity would mean quicker sulfation the next go round. Keep in mind that high current batteries are made of lead sponge, not solid plates. SLI batteries could be destroyed if you're too mechanically rough on them this way.
You will never fail to amaze me with your boardless soldering skills. Somehow you make a jumbled mess of leads more functional than anything I build on a breadboard.
Hehe, if you attend a uni like I did and all the labs keep reusing PCBs ruined by tens or hundreds of other students before you, such skills are quickly developed. Though I don't expect the same reasons in his case ;-)
The problem is the pulses. They have too short a duration imo and cannot wait sufficiently to break down the sulphate crystals any better. Please note that Maintenance free lead acid battery is not compatible with this technique. Please make a battery protection circuit for a lead acid battery. Would be interesting.
First off, the battery should have been cleaned. A starting battery doesn't have the extra room that an RV battery has to allow debris to build up. So, flushing the acid out, flushing the plates with distilled water helps. Replacing the acid with fresh acid AFTER a good series of cleaning/rinsing and charging would be a far better test. I think the distilled water helps draw the build up off the plates. The battery is a simple device and the lead/zinc is still there and usable.
I've used a desulfator as a annual or bi-annual maintenance for lead acid battery's but never a "revival" tool. I have had cheap garden tractor batteries last almost 10 years and my wife last battery in her SUV was bought April 2013 and have been anticipating replacement any day now.
You say the 330R resistor is connected to nothing, but you can actually see it is connected between the 555 timer ground and battery ground. Anyway, great video, as always!
It's quite fascinating to watch you build little circuits. Sadly I have no idea what you are soldering together, the only circuit I understand is the one of an ECG. But I enjoy your videos - keep going.
You should've been adding a distilled water into the battery, I managed to revive a couple of old UPS batteries just by adding water and charging-discharging them slowly multiple times.
0:52 R10 "the connected to nothing" resistor is connected to GND on the back of that PCB, you can see it when that video showed back of the pcb, which is at 1:23 of that video, right bottom corner.
I know somebody who bought these things to put on his batteries (very smart individual he's after all an electrical engineer who knows everything about engineering and apparently might be "God" now). there's one thing to watch out for... constant battery drain and what happens to a drained battery that's overdischarged... guess what damage. So you might think you're actually helping yourself when you might not actually be helping yourself. I much rather get a nice charger that incorporates this in the charge function and I've been very happy with NOCO chargers and even resurrected a few batteries that I thought were for sure dad. The problem with these there's too much snake oil around them so I'm glad to finally see a video. Much like big Clives air ionizer videos.
The only desulfatation method that I've found remotely works for a lead acid battery is charging it from line AC through a 7uF polipropilene capacitor with a rectifier in series. It forces a high voltage until current flows through and then about 400mA. It's not safe nor insulated and needs to be fused to about 1A limit.
I have seen a couple of people attempt to debunk the "MIG Welder battery recovery". It only worked on the non maintenance-free batteries, he was able to dump out the old acid, then filled it up with new battery acid, then hit it with the welder (making certain to observe proper battery polarity) and he hit it just a few times for a few seconds at a time and it was able to recover it to about 90%. The problem is that the battery plates on a normal car battery are very thin and the positive plates are made with a paste of "red lead", and the sulfates causes the paste to crumble off of the plate, and that's what causes them to go bad, as the lead paste will fall to the bottom of the battery and cause a short between the positive and negative plates.
Oh, bummer. Let's see the next ideas. Putting them in the fridge doesn't work either! 😬 Thanks for all the testing and video, dude! 😊 Stay safe there with your family! 🖖😊
I have good experience with such a desulphator, but only on batteries that are good in the first place, but which have been completely discharged by 'accident'. Have taken apart many tens of batteries, and most newer types led acid batteries have almost only lead oxide in one of the poles when they have half their capacity left
I've recently reviewed much online lore about this subject specific to sealed lead acid batteries and concluded: desulphation by purely electronic means (no opening of cells or chemical adjustment) is of very limited utility, pulsing is no more useful than constant current, avoiding overheating is critical and charge/discharge cycling helps. Ultimately, most are not recoverable but some will gain some limited life extension. My personal method therefore is to push 0.1C for a while but avoid heating beyond 120°F, discharge at a similar rate to 90% nominal voltage then repeat this cycle as long as the discharge time continues to increase. This can take days or longer. If the battery will hold a charge and deliver at least half the original rated capacity, I'll keep using it.
@GreatScott, you have to logic this one out..... the true end goal of the desulfator would seem to be to change the internal resistance which will effect how fast the battery self drains; this will not extend capacity but may allow a person to use a battery for longer before it needs to be replaced ..another dependency is likely if all the cells are effected or only a 1 or a few; a bad battery doesn't necessarily mean all cells are equal effected or bad....with that being said I think it's why there's such a mixed bag of people either saying it works or doesn't(really really battery dependent)
I think the true test would be either desulfate each cell or possibly use a modular battery where the batteries can be separated then check individual cells before/after
Reminds me of a saying a long time ago: The designers of battery desulphators knowledge of 555 timer circuit design are inversely proportional to Pb battery electrochemistry knowledge ;)
I've seen videos from reputable channels where people do successfully revive batteries using a desulfator. I remember one on a channel called Steve's Small Engine Saloon where he tried it on four different batteries and if I recall correctly he managed to revive two of them. His takeaway from it was that the desulfator device he had purchased had more than paid for itself by reviving two of the batteries. It DOES WORK, but success is very dependant on the specific condition of the battery. You should look at it as something to try before spending a lot of money on a new battery. If it works, you've saved some money for now, if it doesn't, then maybe it will work on the next battery. Ultimately you will end up replacing the battery, but if it works it gives you some extra time before you have to stump up the cash!
Very good explanation about bateries cycle life. I have expend a lot money in motorcycle bateries and now I can understand better why by less than a year they failed to me... Thank you for your efford and your time to share all this information to us!! Keep creatived as today!! Regards from mx
One thing to watch for with lead acid battery capacity testing is the purkett effect. Basically the faster you drain them the less capacity they have by a very significant amount. The name plate rating on them is a 20 hour discharge. It's not hard to hit 50% capacity on perfectly fresh batteries. Not saying that explains the sulphator not working but it's something to watch for when testing lead acid cells.
Add a diode to the 12v rail between 555 and mosfet. Power the 555 with a 15v(watch limit of VCC ON 555 timer) plug pack and it trickle charges the battery at the same time pulsing it higher. I increased CCA and reduced mOhms on two car batteries that weren’t too dead.
I have had some success using a standard DIY circuit, but using it while charging as well as discharging,. I used a 'wall wart' 12V supply and linked it to the positive rail. via a diode , and added another diode between the positive rail and the battery.
this is the sad part of YT removing the dislike button since it causes time lost scenarios like this, comments can be deleted dislikes can not and show if the source is trust worthy or not by using the voice of many
I have partially restored a deep cycle battery to at least 30% last time I checked. It was left to sit and discharge down to 1.03V when I measured it. The method I've always used was the tried and true (Some call it a farmers trick, others say it's a mechanics trick.... pick your favorite...) just put it on 15 volts, 2-3 amps limited current and keep the battery topped up with fresh distilled water. Sulfates come out of solution when you discharge the battery and will go back into solution when you charge the battery (There is some % that will never revert... but that is a small percentage) When you essentially overcharge the battery while making sure you have proper fluid level you end up putting a good chunk of the sulfate back into solution. The deep cycle battery I talked about above holds 12.45V and I use it in winter to start my truck when the trucks battery is too frozen to give high current.
Desulfation with some cheap AliExpress battery charger did work somewhat for me: my 54 Ah car starter battery only had 35 Ah left (tested with a 1A discharge), after 4 days of desulfation, the capacity rose to 45 Ah.
0:52 Q6 is upside down (and the symbol could be the wrong channel type). The body diode is shown in the direction from BAT+ to (what must be) BAT-. Something will pop. ...and... 0:55 The resistor IS connected on the ground plane on the other side via the thru-hole.
I'm using desulfator from years and stopped to buy batteries.. i was used to change the battery of my motorbike every 2 years, but now it is 5 years old and still working. my personal experience says it works!
In the past, we realized that Car batteries by "charging" them with 230V AC and a 25W light bulb in series, for a few minutes, sometimes that really worked
My heart skipped a beat at the end when you were taking the leads loose. A miss is as good as a mile, but bridging those terminals across that wrench would have been "bad".
Hello, big fan of your work on this channel. I recondition lead acid batteries daily at my job. And I repair battery chargers. There exists commercial grade equipment that actually properly desulfates batteries. However that equipment does not use “high frequency pulses.” Essentially in batteries “high frequency pulses” are snake oil. There is only charging with constant current or constant voltage.
I think the high frequency is largely to prevent overcharging or maybe heat losses. Since you're not replacing the electrolyte, it makes sense to me (a chemist, admittedly, not a battery technician) that you would do that. I mentioned on other comments that the electrochemistry is solid and it can work, but 99% of batteries just don't fail at sulfation and instead oxidize (forming PbO) or shed. In those cases, a desulfator does nothing, regardless of it being pulsed or not.
Yeah sulfation is only one of many issues that a lead acid battery can have that’s very true. Sulfation that is reversible usually is sulfation that is caused by negligent damage in my experience. Think of a relatively new battery that is abused and builds up sulfate groups. If you charge a battery with an equalizing charge that features higher voltage than normal, sometimes you can recover lost capacity and/or cold cranking amps. What I normally do is I discharge the battery first, then charge with constant current at a low rate. I try to deliver as many amp hours as possible into the battery without causing damage. I have a laptop controlled machine at my job that costs $11,000 new. I program all the parameters and walk away. It takes 2-3 days to complete but it can do multiple batteries at once.
Wow this video came out just in time been trying to figure out how to hook my battery to a MOSFET spot welders and the instructions were incomprehensible before this video.
Desulphation of lead acid batteries is a bit more complicated than just passing current pulses to break up the sulphate crystals. First the battery needs to be emptied and washed to remove any sediment. Next the acid is replaced with new solution mixed to the correct specific gravity. The desulphation charge and pulse cycle is run through a couple of times until the two sets of plates are visibly different in colour when charged. The battery is then drained and cleaned once more before being filled with new acid. The capacity will never be as good as the original specifications but it can be used in an emergency situation to get out trouble if there is no alternative. The rejuvenated batteries will last for perhaps a year before replacement is absolutely necessary. This procedure was used for the emergency battery systems on merchant navy ships where the ships might be away in remote areas of the world for a couple of years before returning to civilisation where new batteries could be obtained. Not a trivial process and very time consuming and labour intensive to carry out properly. The other disadvantage is that any clothes worn when carrying out such battery maintenance dissolves into a mass of holes due to the effects of acid and the acidic vapour.
Yep can confirm. Old dude who has garage next to mine does it. He buys old batteries for 5euros washes them with different liquid and some other stuff and does revive them to sell after for 20 euros. Considering that he has to buy new acid and the time he sinks in I keep telling he is an idiot.
"The other disadvantage is that any clothes worn when carrying out such battery maintenance dissolves into a mass of holes due to the effects of acid and the acidic vapour."
Jebus dude, wear PPE and get a fume hood when working with acids and strong chemicals. lol
@@WarrenGarabrandtHe's probably not talking about batteries that you can just pick up and set in a fume hood.
Thanks for sharing this, I didn't know about it. 🙂
I see the potential in emergencies, but thinking about it, the procedure is reaching towards fixing a broken hammer by replacing the handle. If that doesn't help then the head, too.
Same goes for the battery; if the plates are also replaced (assuming the container is not aged/damaged), we got a new battery...
Considering the necessary labour, the involved hazards, potential pollution etc you mentioned, it seems full recycle is the way to go for good reasons.
Mind you, I'm not arguing, just saying, it's probably explaining a lot on how and why things go towards full recycling.
Thanks again for sharing this interesting aspect.
Thank you! Finally someone explaines the fact behind the myth.
And you turned it into 11 minutes for us, thank you!! Time saved for humanity. I appreciate this so much =)
You're very welcome!
But u have to multiply it with amount of view 😝
@@greatscottlab Your next project. Get a 36 amp battery connect it to a ups or 150 watt inverter but ups is better. Do a stress test on it and charge it with the 500 watt ups.
I have a dell laptop the battery is very expensive. I'm not ready to shell for the new one but a 12v 36a battery is cheaper than the dell battery.
@tiepup Exactly!
Guy is doing the work of the dislike button
Scott wasted 30 dayz and made this single compressed video of 11min 🥺 Thanks Scott! ✨
You are welcome :-) I am actually planning a video right now that takes more than 30 days of testing. Will be interesting though ;-)
i want to see the real time tracking sheet ;) it’s not 30 days 1 video. but this video spans of 30 days. how much of the 30 days is actually this video?
How is it "wasting" his time if he makes money with it?
@@greatscottlab Gude, es wäre super, wenn du in diesen Test auch den Volksbedini mit aufnehmen könntest. Er soll wohl das selbe machen können.
You don't really waste time if you learn something from it.
I've always found battery 'rejuvenation' to be no more than folly. If I have a battery that is not doing the job I need it to do, I recycle and replace. Nothing promotes peace-of-mind like a brand new battery. Thanks for the video!
You are welcome. And thanks for the feedback ;-)
NiCd are actually fairly amenable to being restored if they have suffered from the famous memory effect and i have seen wonky NiMH come back to reasonable life as well under some circumstances, i do believe there is a circumstance under which a sort of layer can form which locks away a part of capacity that is not otherwise chemically damaged. But this is an exception rather than a rule and i don't necessarily see that other battery chemistries would work like that; and anyway prevention from a reasonable usage pattern for sure has to be better than any attempt at a cure, and when it's done, it's done, they aren't gonna live forever.
actually, I saw a video the other month where some guy who sells batterys tested a few of the machines on the market on different type of errors on car-batterys. He could actually save 2 of the batterys, but most of the devices did not work :)
Yeah but you can't blame people for wanting to try! Those batteries are expensive, and we all use electricity... so logically we think maybe save money, maybe store power, but... yeah. Maybe rebuilding is the way to go if you have 3 or more batteries, because I've heard many times that usually only one cell is bad, which causes high internal resistance and the battery can never reach full voltage (about 1.5 volts per plate, 3 volts per cell?)
For example i have several batteries and a few cannot charge up to full one sits at around 11 volts after charge, meaning it has a bad cell. Get 2 or more batteries and combine the good cells into a rebuilt battery and you get a battery that works but still has some diminished capacity.
Better would be to learn how to replate the plates, with electricity. Isn't that how they make them in the first place?
Think of it this way, when you apply current to solution, water splits into H and O... the anode (+) (O-) is made there, meaning if you took a grid of wires and put it in the right solution containing lead ions, and connect to the (-) it would plate lead all over the grid. Then you just reverse it and then the thing will have oxygen generated directly on the lead, causing it to turn in to lead oxide?
@@simonlinser8286 "You can't blame people for wanting to try" specifically makes it a super fertile ground for outright scams and in general overblown claims of efficacy and safety (often but not always for malicious reasons), and you have to stay sceptical due to this. And if you leave yourself room for error, you better err on the side of not supporting scams. Which on the other hand shouldn't hold you back from trying to better the world and reduce waste but with the requisite effort and rigour at hand.
The electrochemistry of a desulfator is solid, but often the reason capacities drop in lead acid batteries is more from "shedding": lead sulfate is less dense than lead metal, and like ice forcing against the walls of water bottle in the freezer, it can force the lead metal apart from the plate (or force itself off of the plate). This is very common in high current ignition batteries, which use a lead sponge matrix instead of a plate. Desulfators work for a very specific failure mode, but way more often the battery is simply permanently damaged by the formation of large sulfate crystals that either fall off the plate or force the plate apart. In these cases, the desulfator will do nothing more than cause a bit of hydrolysis in the electrolyte with each pulse.
Obligatory "desulfation works only at full charge" because otherwise the electrons you're pushing into the cell will only be used for the usual lead-acid electrochemistry long before any desulfation occurs (the E0 values for converting sulfate to acid are just a tick higher than those needed to convert lead ions to lead metal). If a desulfator is going to work, it will need to be used with a float charge that's enough to keep the battery charged between pulses. It need not be more than what's needed to counter self-discharge, and that's going to vary a lot from battery to battery.
And then there's the whole issue of lead oxide generation over the battery's lifetime, which also represents a permanent chemical loss of capacity.
Long story short, for 99/100 batteries, recycling and chemical processing are the only ways you can really revive them. For that one out of the bunch that's just not been used in a while, a desulfator could work but needs tuning, special conditions, and constant monitoring to make sure that there's no hydrolysis side reactions.
Thanks man, great insight about the process and the chemistry behind
That is a very awesome explanation of it!!!!
The only caveat is that some AGM batteries are built well enough with thick enough fiberglass plates that they can hold together a lot better, even after being obscenely sulphated. I have had good luck with recovering some of the AGM UPS batteries by popping the tops off and slowly adding battery electrolyte and hitting them with 15 volts and a MIG welder
Exactly this. The grey sludge inside a used battery is just lead which has been lost off the plates and had either reduced the size of the plate or is stopping the plate from functioning.
@@astrawally8448 And also sometimes actually shorts out the plates altogether, even. Deep cycle/marine/golf cart/forklift batteries have much thicker plates and that's why they can be discharged to such a low level and be recharged and still function.
@@astrawally8448 and you see videos on youtube of people washing down their drains. Just unbelievable!
Mostly unrelated to the video content, but I noticed when you were showing shots of the PCB layout in Altium that your polygons are overflowing the PCB edge. I was having the same issue and I recently figured out how to fix it. If you duplicate your board outline to the Keep-Out layer, you can assign a rule to have your polygons maintain a specified distance from any Keep-Out layer object, and effectively follow the contour of the Outline. Keep up the great work!
Thanks
This approach is fine, hovewer, more 'correct' and easier in the long term approach is using BoardOutlineClearance rule under Manufacturing rule set. This way, you will not need to manually update keep-out layer each time you need to redefine board size and/or shape.
Even easier is to use the polygon manager and define the shape from the board outline.
Even easier, send your schematics and max dimensions to China and for 5 bucks including shipping you get 5 ready made boards.
Can we just have AI learn tricks like this? 😀
The circuit I built is very similar to this. I've tried many different combinations of pulse width, frequency, voltage, and current over the last 10+ years. It has never once revived a battery in any way. It might work for some edge cases but a well cared for battery almost always fails with a dead cell like the first battery shown here (either shorted out or falls apart) and this can not be fixed without rebuilding the whole battery.
Thanks for the feedback. Appreciate it to hear this from others as well.
I agree, batteries simply fall apart. Especially car batteries.
Would those edge cases be deep cycle batteries or solid plates used? 🤔
I hope I can find a scientific paper one day that shows it possibly works, or else the products are all a lie.
Only fillable Wet cell batteries if cell has not collapsed can be revived but not using this approach, you need alot higher current and higher voltage to boil it
@@james2hackett870 Do you mean the "Arc welder fix" that boils the acid in the cells may actually have some chance of working?
From what I've had heared - reverse charging is one of the ways to restore battery:
First You should discharge the battery to 0, by adding a bulb for a day or so
Then you connect charger backwards - positive wire to "-" terminal and the positive one - to "+" terminal, charge up, than again discharge to 0 with a bulb and charge this time correctly.
The idea behind this is that sulphotation occurs, I believe, only on anods. By charging the battery backwards - anod and cathod are changing places, so sulphates from anod should dissolve.
Did you ever tried this method? did it work?
@MoonArk no, haven't ever
@@AyraSikil thank you for the idea though :)
I read some on this topic a while ago, and if I remember correctly, the sulfate that is created during normal use is thin, spongy and easily converts back into the electrolyte when charging. Left for too long however, the suflate hardens and does not covert back. The desulfators can in the best case crack this hard layer. This would verify other comments about the process not increasing the capacity (the electrolyte remains weak) but potentially getting an improved current flow (less plate resistance).
The pieces nocked off by the process fall to the bottom of the battery where there is a collection chamber. When this fills up and touches the bottom of the plates, the battery is completely toast.
Yeah this seems like one of those things that if you're gonna do it, should be done as part of a regular battery maintenance routine, not something that waits until problems arise, which by then its likely too late.
30 days of strategic planning and implementation in 11 minutes video. As a fellow electronics video creator, i can really appreciate your efforts. Thanks for this lesson Mr. Scott
I would like to see one video where somebody makes a lead acid cell in a glass jar, sulfates it.... And then does various de-sulfurizing circuits with a time lapse camera.
That sounds like fun :-) I can put it on my to do list
It's great that videos like this one are put up. Too many times someone will put up a video making promises and they turn out to be little more than nonsense and in some cases, a lot of these hacks can be quite dangerous.
As a technician, one of my tasks is to physically check the batteries and determine their age. For fire alarm systems and most emergency lighting packs, we recommend strongly that the batteries are to be replaced every six years even if they pass the load test. While they may be recharged to full voltage, they would discharge too rapidly to be of use in an emergency situation and can actually create a hazard. An example of that would be a stairwell that is pitch black due to no lighting when the main power fails and the emergency lighting also fails because the battery is too old.
Lead acid batteries are a bit tricky with their capacites, the 44Ah are messured with a C20 (2.2A) discharge over 20h, if you use a higher Discharge the Capacity is much much lower.
IIRC, at C/10, you get around 70% of the rated AH. Each battery design has its own set of discharge curves. Some of the better SLA batteries I've bought have the discharge curves stenciled right on the side of the battery.
I also read in the materials from a battery tester that a good percentage of batteries returned as defective are within specs. This could account for the apparent success of magic circuits.
we test lead acid batteries mostly for load. If it can provide a high load. Like for the start of an engine. That way we know the internal resistance is low. And if we make a full test the capacity isn't far off. Its simpler and quicker to test with a real load.
After you sorted the batteries you can still test the true capacity if desired.
All types of battery (not just lead acid) have their capacity measured at some specified load, and capacity invariably dropd at higher loads. The difference with lead acid starter batteries is that they also have a CCA (Cold Cranking Amps) rating as well as capacity, which is a measure of the maximum useful current that battery can supply at -18 Celsius.
@@ferrumignis Car batteries have CCA and CA listed as that should be all they are used for, they are not meant to be discharged more than ~10%. Something like an electric forklift has deep cycle batteries, which spec time at a certain voltage and current.
@@pontiacg445 That's why I made it clear I was talking about lead acid _STARTER_ batteries.
Thanks for throwing in the issues and fix for the PCB design. I think a lot of people are put off by worrying their boards will not work as intended when they arrive, and as many people have budgetary constraints, find this a show stopper. Being able to diagnose and then repair the design with a workaround means a non-critical design failure is manageable, and you'll learn something along the way too. Dealing with faults and faulty designs is really valuable as a hobbiest, and also if you want to get into component level repair and hacking.
From what my research on these has shown, and using one myself, there is a point of no return for the batteries. If they are lightly sulfated it CAN bring them back to life. But if the battery sat dry, or has an internal short or broken plate no amount of desulfating will revive it.
One other thing to keep in mind is while the battery may not have enough juice to start a car, it can still power lower-draw devices in an emergency if you are smart. Granted it is not totally nuked, to begin with.
you're a genius and you explain things perfect, but the main reason I subscribe to your channel is I'm addicted to the way you say "scooter"
There is a KNOWN good way to desulfate batteries. Take them to a recycling point, where they will be melted down and processed into new batteries.
Jokes aside, I have had limited success with this. It seems that it is very battery dependent. I've saved only a handful with a consumer unit but most go to the "core charge" pile.
Haha sounds like a good plan ;-)
I'm glad someone finally tackled this I've been sick of the fake videos for years... An old battery is worn out it's not coming back
Be aware that lead acid batteries specifically has their nominal capacity of say 50 Ah rating under the implied C20 standard; its the capacity if run from full to flat in a duration of 20 hours, so here at 2.5A nominal.
Desulfating does nothing if the electrolyte is depleted. I have recovered many SLAs that were completely dead but they all needed topping up with deionised water. You never get the original capacity back but some got almost 80%. Useless for high drain but great for solar backups, desktop supplies and experimenting. I never used any 'special' desulfating circuitry, holding the the voltage at around 14v to outgas the cells works just fine. This doesn't do anything more than knock the sulphate off the lead plates which exposes the fresh plating and reduces the resistance to allow more charge.
I love this straightforward demonstration of how the circuit does what it claims to in terms of function but does not give the claimed result. Particularly the fact that you highlighted the importance of actually testing the thing that is supposed to be improved (capacity).
At the risk of waaay oversimplifying things, rechargeable batteries are going through the equivalent of rusting and then de-rusting. As another commenter pointed out, the starting and ending materials going from charged to discharged and vice versa have different properties, including how much volume they take up. This repetitive process of changing volume leads to mechanical degradation which cannot be reversed with a circuit.
3:14 what you might be experiencing here is actually an internally shorted cell or a cell that's been reverse charged. This can be fixed you'd need to charge it with very high current and pulsing it, essentially kinda damaging it in the process a little. Not the best solution but it does work.
Now as for desulfation, I have bought myself a battery desulfator, one of the cheaper kinds. It hasn't actually desulfated anything for me but I noticed it did solve some other problems that those batteries had. Self drainage was gone. on 1 battery the voltage would drop down to 12.5v overtime after fully charging it. Now it stays at 13.2v which is a significant improvement so it isn't entirely useless.
What I've found that actually desulfates the battery is by just cycling it with high current. I've even gotten lead acid batteries that were at 0V back to 13.1V with this method and it works really well. You just have to stop discharging the battery at 10.5v to avoid reversing the cells. What you should notice is that the capacity increases with each cycle. It might take time till it starts increasing but you will notice it. From my testing it usually takes around 20 cycles to get it back to a good condition
from nicd charging i remember that they could handle high current charging very well. the output afterwards was better compared to slow charging and they had less memory effects
high current charging gargabe cells worked several times.
Any sulphation that such a desulphator circuits can remove can be removed much easier by simply giving the battery a good charge and the occasional "equalisation charge". Those old batteries aren't primarily losing their capacity due to sulphation, but because the plates are slowly falling to bits and losing surface area.
When a cell's plates have lost enough material they tend to twist and short together (especially thin plated batteries like automotive starters), or the debris in the bottom of the cell builds up enough to touch the plates and causes much the same effect. That is why you couldn't bring the voltage of the first battery up. It has a shorted cell and is effectively a "10 volt battery" now.
Trying to rejuvenate starter batteries is pretty much a waste of time. However bigger deep cycle batteries, such as the ones they use on electric forklifts can be. Their useful period can be extended by increasing the strength of the acid. Of course that actually hastens the ultimate demise of the cells, but more utility is obtained from them during that EOL phase.
Also charging the cells to a higher voltage can get a bit more use out of them, but again, trading this for a faster total demise. 12 volt systems can be charged up to between 15.0-15.2 volts. It gives the cell/battery more useful capacity, but it speeds up the degradation of the +ve plate. This can only be done with flooded batteries. Overvolting SLA batteries such as AGM and GEL is not a good idea.
Desulfators do work. I have one and have successfully revived a couple batteries. But it only works if you also add a charger.... In other words u have to charge the battery at the same time you desulfate it. But that was 2 out of 100+ batteries
Yes this is true i thought that myself, it needs to be kept above the knee of the curve for the sulphate to convert back, as you are taking power with the de-sulphator you should be trickling it at the same time.
When the desulfator describes itself as having a 10kHz 'frequancy' you already know it is a terrible quality product... What even is a 'frequancy'...
@@someguy4915 frequency refers to the size of the pulses and listing the frequency of the pulses doesn't make it junk by any measure. An ideal desulfator would have charge frequencies that are all over the map.
Thank you for your technical integrity.
So much false information and fake products across the internet. But, it was also the case when all we had was TV, including now. Beware the pharmaceutical industry.
While travelling a lot for work last year, I had to put the batteries of both of my cars on my big battery charger (the kind with wheels) which went into desulfation mode. I thought it did a surprisingly good job and I'm still using the batteries, but I can't say for sure what a charger without a desulfation mode could've done. Now I want to try to get a couple of batteries and experiment with them.
Thanks for sharing
Great video as always. It’s interesting, that I see no comments from any farmers. I was raised on a farm and most farmers had a simple desulfator made from nothing more than a rectifier and a run capacitor from and air conditioning unit. You plug one end into 120 vac and connect the other to the battery. This gives you a DC out with a large AC ripple of 120hz which, over time, breaks down the sulfation. This will not work on batteries with bad cells but will work about 50% of the time. Something to remember though…this simply postpones the inevitable. The sulfation doesn’t magically disappear but falls to the bottom of the cells. Unless the battery is flushed this will eventually cause a problem.
Thanks for debunking this finally, I was wondering if there was a way to possibly revive my 102Ah deep cycle battery. We here in South Africa experience daily power cuts 2 hours, 3x per day (referred to as loadshedding by our power utility that currently can't provide our country with enough electricity). I recently lost a deep cycle 102Ah battery due to this constant charging, discharging cycles in my inverter. The battery is just past one year old. Lithium is better, but unfortunately outside my price range for now. Keep up the good work.
Discharging a Lead Acid battery below 50% on a regular basis will kill it off very quickly. If you are doing this then adding a second battery in parallel will almost certainly more than double the service life.
LiFePO4 can be surprisingly cheap if you by the raw cells and add a flying capacitor balancer/BMS. A good cell like the EVE 280AH ones will last around 5000 full cycles where you can discharge down to about 20%. Remember to compress the cells so prevent them bulging under use. This means it is almost twice the usable capacity of a lead acid for a given label AH and if looked after properly will last 10 years or more. Payback is surprisingly quick.
I'm off-grid with about 400AH@48V LiFePO4 and love them.
Consider exploring the option of creating your own power storage system using used medical LiFePO4 batteries that will probably have around 80% capacity. This DIY approach could be more affordable and worth considering. LiFePO4 batteries are generally safer and more stable than LiIon batteries, but are less energy-dense. However, they can last up to five times longer and perform better at lower temperatures. It is possible to create a system using inexpensive LiIon scooter batteries as well. A DIY system should cost significantly less than a commercial option. Additionally, having more battery capacity than you need means that each battery capacity will be used less, potentially extending their lifespan. A good BMS should help you set the limits to charge/discharge to prolong them also.
@@chrisjc2k thank you.
@@AndyFletcherX31 thanx, i'm aware of SLA DoD but our power cuts are so severe, that it's impossible to keep a 50% DoD. I know more batteries will buffer this, but unfortunately batteries are now a commodity in South Africa, making them scarce or very expensive. But I'll explore the options suggested. Thanks
@@Martin4982 I think you should not run heavy duty appliances when the power is off . Fridges, kettles ,vacuum cleaners - these kind of things . I have small pv system but i keep only my computer on it and i fully manage it - the 15 year old 135 AH battery has about half capacity left but is usable only with direct charging
Thsnk you for your video i have been telling people for a long time that there is no simple solution to battery sulphation and that it is not practical for the average person. As usual top notch video from you as always!
I use JLC myself whenever I want a nice board. They do a great job. But the price is never just $2. It could cost just $2 or $4 for the board itself (I think the most I paid was $5), but the shipping can be as much as $15-$20, and I have never received it in a week.
Oh man… I was so happy to see this video and give up to build my “discharger” which was in my mind to “reset” the Pb battery from my alarm system. Now just ordered a new one, thanks you no need to waste more time and energy. Please more Busted videos!
It would be worth checking the composition of the electrolyte in the big battery. Often times the batteries dry out from overcharging and need water added over time.
My first thought too as soon as he brought out that first dead battery; top up the water if it won't hold a charge.
Even so-called SLA, just means the electrolyte holes are a bit harder to get to
Or its dropped 1 cell ?
Dear Scott, good job! Frankly speaking, I never believed in the "healing current" for lead-acid batteries.
It *can* work, but most batteries don't fail this way. Most of them shed from the plates long before sulfation is ever a real problem.
Thank you for leaving in, explaining and fixing the mistake. It greatly helps to deal with the imposter syndrome in me (and I presume the same applies to many other people).
Anyone can make any mistake. The question is, what you do to avoid it the next time and what safeguards you build into your habits in general, based on such experiences.
In short: how you learn from it.
I _love_ this approach, thank you again.
quite frankly, i was surprised Scott fell for this mistake. Or was it a planned mistake? ahem.....
Sharing the failures is also part of what a scientist does. Thanks for sharing!!
Hi. Good try. But you need to ad distilled water or (more better) mixture of water and electrolytes (1 to 8 mix). Because your separator inside the battery looks like to "dry" and sulfate crystals won't dissolve.
I just wanted to point out the other person's PCB you stated that R10 is connected to nothing, it is connected to ground, pin 1 IC & led - as per circuit if you check with the multimeter it is connected.
Anyway thanks for all the information you are great 👍👍
In my experience these things do not increase the capacity but it will increase the current the battery can put out
That actually does make a lot of sense.
I would rather have both.
senin gibi teknik bir insanın bu işe el atmasına sevindim. teşekkürler.
video's like this are great because you show you have thoroughly tested these things and proven them to be almost worthless. its better to do a video like this than just simply saying it will or wont work
Great! I had one of these circuits on my 'todo list', to recover a few of my dead batteries. It's a bit disappointing to see such dubious results, but at least you just saved me 30 days of dicking around with magic pixie circuits. Thank you, much appreciated!
So, perhaps now I'll move to plan 'B' and melt down some of my dead batteries, to harvest the lead.
I have an video idea for you. Convert a lead acid UPC (uninterruptable power supply) to one that uses 18650 Li batteries. Will there be a cost savings? What are the advantages/dis-advantages?
For sure it won't be cost effective hence why we use lead acid instead. Thought your usage may change the overall price. If you often get power lose or/and extended power outrage your lead acid will die faster and depending of how your time is worth/or how critical your infrastructure is, it could be indeed a better alternative. I was reading a litlte about that and using LiFePo4 could be a nice choice instead of the typical lithium ion. Advantage: more recharge cycle than typical Li-ion (and way more than lead acid), also safer. Downside: lower discharge rate than lead-acid (around the same as li-ion i think?) and price :/.
I have seen these little circuits for sale for years, sometimes at high prices. I was always skeptical, but didn't have the time or money to pursue it.
THANK YOU, Scott, for debunking this for us, appreciate it very much.
years ago I found a commercial desulfator advertised with great reviews for extending golf cart & forklift battery life. They were not cheap, almost double the price of the deep cycle battery, but at the time I was in need of reliable emergency back up batteries, so I combined them with solar trickle chargers to keep them going unattended for months.
6 months later I needed to call on and use the batteries, only to find everything dead, so dead that they wouldn't revive with a normal charge when I got them back to civilisation.
An expensive learning experience.
@@bigbadwolf1966 And did you measure if the trickle charge could keep up and more with the consumption of the desulfator. Seems in your case you simply flattened the battery completely, sitting in that state for while will ensure failure.
The problem is not that lead batteries only sulphate, they can have lots of other faults, such as internal short circuits, interruptions or most commonly one plate simply stops working.
If you've seen YT videos where people in more southern countries repair batteries on the street, note that even these skilled craftsmen MUST buy one plate new, I can't remember which one, it CANNOT be recreated in the kitchen/on the street!
Thanks for the feedback. Good info
Dude i have been following you since the olden days of instructables and i gotta say you have always found a way to make projects so interesting even if they were a gimmic or trivial!
I love your videos
Thanks mate :-)
Priceless!
This is the content type we need to learn and go forward in knowledge.
I believe your results. Not sure what's going on with them, either... I can't make sense of why it would drop like that.
Hmm...
Pretty complicated thing to put together and test for the same amount of time, though.
It is a mystery
@@greatscottlab couldn't the capacity dropped even more due to the "stress" of discharging them again in order to measure their capacity, since they were already in bad shape?
@@RussellTeapotyep..discharging under like 50% for lead acid is a death sentence
I have a "smart" charger from Dunlop,and after some speculating,it's way off desulfating is turning on every 1-2 seconds with it's max charging voltage and the max current (14.8V 1 amp each second or so)
It managed to revive 3 of my lead acids that i changed(or added) distilled water in order to refresh the cells. Their capacity more or less refreshed and they were strong enough to not drop their voltages too fast under heavy loads. Although i forgot about them and now at least 2 of those are definitely dead for sure,still gotta try to see what they can do some day
Yeah some will raise voltage upto 16 maybe 16.5v for this
It would be good to see a forklift mechanic's opinion. My old pop used to disulfate and get some good results. Or see what happens if you ran these on the dead battery.
Forklifts have much more durable batteries than a car.
The lead plates in a car battery are paper thin and covered in a paste that falls apart.
Unless you have a brand new car battery that got sulfated in storage, the possibility of restoring it is near 0. They are just far too delicate. The more often a car battery is drained, the quicker it falls apart internally. It's really only intended to start an engine, or get discharged a small percentage.
Forklifts, and batteries designed for renewable energy and deeper discharge are vastly more durable, with golf cart batteries and backup batteries still being better than car batteries.
So if there is ever a battery worth attempting to desulfate, it's a forklift battery.
Commercial "desulfators" are typically first and foremost chargers, lead-acid batteries likes to be kept charged, so keeping them charged for a while makes them better for a time compared to not keeping them properly charged. They might also seem much better after a prolonged charging session, as in keeping a higher voltage without load or with insignificant load. But lost capacity is lost capacity.
Creators who upload on a Sunday are the best
;-)
Very few times I got to make Lead-Acid batteries, that have been through a deep cycle, ever work again. Your results do not surprise me in all honestly.
Has anybody though tried to mechanically breakup the crystals? Like with an ultrasonic transducer? I have absolutely no idea if it would work but wouldn´t
mind seeing a video on it! :-)
That sounds interesting. Soon there will be a video about ultrasonic cleaning............we will see ;-)
The shed crystals, if you decided to do it this way, would then be permanently excluded from the electrochemical reaction going on in the cells. That would mean a potentially large, permanently lost capacity; but it probably would restore the peak current output. In a pinch it could work, but that battery would need prompt replacement since the drop in capacity would mean quicker sulfation the next go round.
Keep in mind that high current batteries are made of lead sponge, not solid plates. SLI batteries could be destroyed if you're too mechanically rough on them this way.
thanks for this enlightening video. now the discussion with my colleagues is over after years. always make sure your battery is in good condition.
Its along the same thing as "free" power. very interesting video 2x 👍
Thanks ;-)
You will never fail to amaze me with your boardless soldering skills. Somehow you make a jumbled mess of leads more functional than anything I build on a breadboard.
Hehe, if you attend a uni like I did and all the labs keep reusing PCBs ruined by tens or hundreds of other students before you, such skills are quickly developed.
Though I don't expect the same reasons in his case ;-)
The problem is the pulses. They have too short a duration imo and cannot wait sufficiently to break down the sulphate crystals any better. Please note that Maintenance free lead acid battery is not compatible with this technique.
Please make a battery protection circuit for a lead acid battery. Would be interesting.
First off, the battery should have been cleaned. A starting battery doesn't have the extra room that an RV battery has to allow debris to build up. So, flushing the acid out, flushing the plates with distilled water helps. Replacing the acid with fresh acid AFTER a good series of cleaning/rinsing and charging would be a far better test. I think the distilled water helps draw the build up off the plates.
The battery is a simple device and the lead/zinc is still there and usable.
I love magic batteries
Everyone does ;-)
I've used a desulfator as a annual or bi-annual maintenance for lead acid battery's but never a "revival" tool. I have had cheap garden tractor batteries last almost 10 years and my wife last battery in her SUV was bought April 2013 and have been anticipating replacement any day now.
Everyone argues about disulfation and nobody mentions the frequancy typo on the commercial charger? Very confidence inspiring...
You say the 330R resistor is connected to nothing, but you can actually see it is connected between the 555 timer ground and battery ground. Anyway, great video, as always!
It's quite fascinating to watch you build little circuits. Sadly I have no idea what you are soldering together, the only circuit I understand is the one of an ECG. But I enjoy your videos - keep going.
That's the reason why I love following you Sir. Thank u
This is what I like about this channel that he will make his own improved version
You should've been adding a distilled water into the battery, I managed to revive a couple of old UPS batteries just by adding water and charging-discharging them slowly multiple times.
0:52 R10 "the connected to nothing" resistor is connected to GND on the back of that PCB, you can see it when that video showed back of the pcb, which is at 1:23 of that video, right bottom corner.
Yep, and it has a purpose as well. Reducing supply noise for the 555.
I know somebody who bought these things to put on his batteries (very smart individual he's after all an electrical engineer who knows everything about engineering and apparently might be "God" now). there's one thing to watch out for... constant battery drain and what happens to a drained battery that's overdischarged... guess what damage. So you might think you're actually helping yourself when you might not actually be helping yourself. I much rather get a nice charger that incorporates this in the charge function and I've been very happy with NOCO chargers and even resurrected a few batteries that I thought were for sure dad. The problem with these there's too much snake oil around them so I'm glad to finally see a video. Much like big Clives air ionizer videos.
It's amazing how whenever I start looking up something on RUclips within a week or so you're making a video about the same thing.
You’re always have such neat handwriting
just another Great video form GreatScott !
Thanks for this lesson
What you need is the old school method! 100w light bulb and a diode! You get a nice half wave ripple of reasonably high current pulses!
The only desulfatation method that I've found remotely works for a lead acid battery is charging it from line AC through a 7uF polipropilene capacitor with a rectifier in series. It forces a high voltage until current flows through and then about 400mA. It's not safe nor insulated and needs to be fused to about 1A limit.
Yes, please.. keep calling out these scammy youtube channels!!
I have seen a couple of people attempt to debunk the "MIG Welder battery recovery". It only worked on the non maintenance-free batteries, he was able to dump out the old acid, then filled it up with new battery acid, then hit it with the welder (making certain to observe proper battery polarity) and he hit it just a few times for a few seconds at a time and it was able to recover it to about 90%. The problem is that the battery plates on a normal car battery are very thin and the positive plates are made with a paste of "red lead", and the sulfates causes the paste to crumble off of the plate, and that's what causes them to go bad, as the lead paste will fall to the bottom of the battery and cause a short between the positive and negative plates.
Oh, bummer. Let's see the next ideas. Putting them in the fridge doesn't work either! 😬
Thanks for all the testing and video, dude! 😊
Stay safe there with your family! 🖖😊
I have good experience with such a desulphator, but only on batteries that are good in the first place, but which have been completely discharged by 'accident'.
Have taken apart many tens of batteries, and most newer types led acid batteries have almost only lead oxide in one of the poles when they have half their capacity left
scott is a great person Respect
Thanks mate :-)
I've recently reviewed much online lore about this subject specific to sealed lead acid batteries and concluded: desulphation by purely electronic means (no opening of cells or chemical adjustment) is of very limited utility, pulsing is no more useful than constant current, avoiding overheating is critical and charge/discharge cycling helps. Ultimately, most are not recoverable but some will gain some limited life extension.
My personal method therefore is to push 0.1C for a while but avoid heating beyond 120°F, discharge at a similar rate to 90% nominal voltage then repeat this cycle as long as the discharge time continues to increase. This can take days or longer. If the battery will hold a charge and deliver at least half the original rated capacity, I'll keep using it.
Great video from Great Scott - thank you! 👍😀
I really like that we live in a time where opinions are equal to facts
@GreatScott, you have to logic this one out..... the true end goal of the desulfator would seem to be to change the internal resistance which will effect how fast the battery self drains; this will not extend capacity but may allow a person to use a battery for longer before it needs to be replaced ..another dependency is likely if all the cells are effected or only a 1 or a few; a bad battery doesn't necessarily mean all cells are equal effected or bad....with that being said I think it's why there's such a mixed bag of people either saying it works or doesn't(really really battery dependent)
I think the true test would be either desulfate each cell or possibly use a modular battery where the batteries can be separated then check individual cells before/after
Reminds me of a saying a long time ago:
The designers of battery desulphators knowledge of 555 timer circuit design are inversely proportional to Pb battery electrochemistry knowledge ;)
01:19 the giant smile of TODAY. Thanks GreatScott!!!!! ;)
I've seen videos from reputable channels where people do successfully revive batteries using a desulfator. I remember one on a channel called Steve's Small Engine Saloon where he tried it on four different batteries and if I recall correctly he managed to revive two of them. His takeaway from it was that the desulfator device he had purchased had more than paid for itself by reviving two of the batteries. It DOES WORK, but success is very dependant on the specific condition of the battery. You should look at it as something to try before spending a lot of money on a new battery. If it works, you've saved some money for now, if it doesn't, then maybe it will work on the next battery. Ultimately you will end up replacing the battery, but if it works it gives you some extra time before you have to stump up the cash!
Very good explanation about bateries cycle life. I have expend a lot money in motorcycle bateries and now I can understand better why by less than a year they failed to me... Thank you for your efford and your time to share all this information to us!! Keep creatived as today!! Regards from mx
One thing to watch for with lead acid battery capacity testing is the purkett effect. Basically the faster you drain them the less capacity they have by a very significant amount. The name plate rating on them is a 20 hour discharge. It's not hard to hit 50% capacity on perfectly fresh batteries. Not saying that explains the sulphator not working but it's something to watch for when testing lead acid cells.
Yes. Presumably he did not change the discharge rate between tests.
Add a diode to the 12v rail between 555 and mosfet. Power the 555 with a 15v(watch limit of VCC ON 555 timer) plug pack and it trickle charges the battery at the same time pulsing it higher. I increased CCA and reduced mOhms on two car batteries that weren’t too dead.
I was told many years ago that it was best to use these while the battery was charging not that I've had need for them great vid.
I have had some success using a standard DIY circuit, but using it while charging as well as discharging,. I used a 'wall wart' 12V supply and linked it to the positive rail. via a diode , and added another diode between the positive rail and the battery.
this is the sad part of YT removing the dislike button since it causes time lost scenarios like this, comments can be deleted dislikes can not and show if the source is trust worthy or not by using the voice of many
I have partially restored a deep cycle battery to at least 30% last time I checked. It was left to sit and discharge down to 1.03V when I measured it.
The method I've always used was the tried and true (Some call it a farmers trick, others say it's a mechanics trick.... pick your favorite...) just put it on 15 volts, 2-3 amps limited current and keep the battery topped up with fresh distilled water. Sulfates come out of solution when you discharge the battery and will go back into solution when you charge the battery (There is some % that will never revert... but that is a small percentage)
When you essentially overcharge the battery while making sure you have proper fluid level you end up putting a good chunk of the sulfate back into solution. The deep cycle battery I talked about above holds 12.45V and I use it in winter to start my truck when the trucks battery is too frozen to give high current.
Desulfation with some cheap AliExpress battery charger did work somewhat for me: my 54 Ah car starter battery only had 35 Ah left (tested with a 1A discharge), after 4 days of desulfation, the capacity rose to 45 Ah.
Your analysis is super bro 👍
As always I learned from your video thanks 🙏
Amazing video Scott. Thanks for that
0:52 Q6 is upside down (and the symbol could be the wrong channel type).
The body diode is shown in the direction from BAT+ to (what must be) BAT-.
Something will pop.
...and...
0:55 The resistor IS connected on the ground plane on the other side via the thru-hole.
I'm using desulfator from years and stopped to buy batteries.. i was used to change the battery of my motorbike every 2 years, but now it is 5 years old and still working.
my personal experience says it works!
In the past, we realized that Car batteries by "charging" them with 230V AC and a 25W light bulb in series, for a few minutes, sometimes that really worked
My heart skipped a beat at the end when you were taking the leads loose. A miss is as good as a mile, but bridging those terminals across that wrench would have been "bad".
Hello, big fan of your work on this channel. I recondition lead acid batteries daily at my job. And I repair battery chargers. There exists commercial grade equipment that actually properly desulfates batteries. However that equipment does not use “high frequency pulses.” Essentially in batteries “high frequency pulses” are snake oil. There is only charging with constant current or constant voltage.
I think the high frequency is largely to prevent overcharging or maybe heat losses. Since you're not replacing the electrolyte, it makes sense to me (a chemist, admittedly, not a battery technician) that you would do that. I mentioned on other comments that the electrochemistry is solid and it can work, but 99% of batteries just don't fail at sulfation and instead oxidize (forming PbO) or shed. In those cases, a desulfator does nothing, regardless of it being pulsed or not.
Yeah sulfation is only one of many issues that a lead acid battery can have that’s very true. Sulfation that is reversible usually is sulfation that is caused by negligent damage in my experience. Think of a relatively new battery that is abused and builds up sulfate groups. If you charge a battery with an equalizing charge that features higher voltage than normal, sometimes you can recover lost capacity and/or cold cranking amps. What I normally do is I discharge the battery first, then charge with constant current at a low rate. I try to deliver as many amp hours as possible into the battery without causing damage. I have a laptop controlled machine at my job that costs $11,000 new. I program all the parameters and walk away. It takes 2-3 days to complete but it can do multiple batteries at once.
Wow this video came out just in time been trying to figure out how to hook my battery to a MOSFET spot welders and the instructions were incomprehensible before this video.