Hope the video saves you money! If you're going to charge Lead Acid batteries, set the output voltage between 13.8V & 14.2V. Always charge in a cool, shady area. To be safe, place the power supply on a concrete or tile floor. The PSU simply supplies a maximum output of 30-31 amps @ the voltage you set, the BMS, if it's any good, is what handles the charging and tapers off the current as the 12V battery nears full charge. If you're concerned about "stressing" the BMS, then the solution is simple, use a lower charging voltage of 14.4 to 14.5V, doing so will also extend the cycle life of the battery. Thanks for watching
That is exaclty what I wanted to say.. this needs a Current control pot.. which I think it can be done by taking one small dc-dc module which have cc and adapt the control part to this power supply.
@@cgmarch2359 No need for it, the PSU output based on my tests is limited to around 30-31A. All you have to do is set the correct output voltage, and the BMS if it's any good, will take care of the charging and stop the flow of current as the battery nears full charge.
This is in fact a CV-FloatCharger and setpoint (charge voltage) is limited to 14.65v in this case. You ofcourse can charge also @ true float voltage lead acid eg @ 13.4v. CV-FloatCharging = CC/CV.
A few people have raised extremely valid concerns below. Being, it doesn't stop charging. it will keep pumping in current, even if it drops down below half an ampere. Most battery chargers will stop the charging process at 0.5 amps, but this will not. The problem with that is, BMS's built onto most 12V batteries are primitive and will prevent over voltage charging to prevent battery fires. But relying on the batteries BMS, charging right up to that point every time will definitely cause irreversible damage to your battery. What you need to add to this setup, is a relay and an automatic low current (0.5A) off switch to prevent serious damage to your battery... and if you value your power supply, maybe consider over current protection too. One point that no one has raised is the charge current when the battery is under 30% charged needs to be limited (especially for batteries under about 120ah). This is usually accomplished by 3-stage chargers, by limiting the charge voltage (3 stage = constant voltage , constant current, constant voltage) the absolute gold standard and bare minimum requirement in charging 99% of batteries. Over currenting batteries with less than 30% charge is crazy damaging to any battery. If you really want to use this cheap method, there is a safe way to do it... Typically you need to know the C rating of your battery. Or at least the maximum charge rating in amps. Then choose a power supply that will taper the voltage to maintain the integrity of its max current. Then choose a power supply whos maximum current that is 10 to 30% of your batteries maximum current rating. The other thing you must do is also set the voltage for lithium to about 13.4 - 13.6V. You might only reach 95% charge but you won't F your battery either by (slightly) overcharging it. This will ensure you don't destroy your batteries too fast. Another thing, don't believe what this guy says about the magic he believes about what a BMS does. A BMS will not assume you have hooked up a random power supply to it. Its certainly not smart enough to regulate current. The reason the current falls, is due to the nature of the chemistry within the battery changing as it is becoming closer to being fully charged. The BMS will balance-charge the cells at a very slow rate, it will protect (with on/off ONLY state mosfets). It will never regulate voltages or currents. It will only completely STOP fire-causing voltages or currents. It WON'T stop you from destroying your battery. Another good idea is to get a cheap solar pannel lithium charger and use that in conjunction with this power supply. Just use the power supply at 15V and plug it into the solar pannel input on the solar charge controller. 95% of your problems (5% still being exposed high voltage) solved.
hello there i need some help, i have about 16s 24v 512ah ,i just did the setup with headway cells so which configuration do i look our for or do i need more than one charger?
This is very well explained for safety and longetivity of the batteries, yeah safest way is run it through the SCC and let the SCC take control, cheers!
Noticed the guy never responded to your concerns. I have one of these power supplies and was interested in using it as a charger for my LifePO4 battery. I suppose I could just stop the charger manually when it hits 14.6 volts which require constant monitoring.
After watching your video, I purchased one. It took about two weeks to arrive. I just finished wiring it up and am charging a 200 amp hour system of two 100 amp hour LiFePO4 batteries that are wired up in parallel. It is working great! Perfect! Just what I wanted and for only $25. Thanks for posting this video!
I run three of these in parallel to throw 62.5 Amps in to my 120 AH lifepo4 battery. Always check the output with a multimeter before charging, only takes a second but is a good thing to do so you don't accidently fry your batteries or BMS.
Not at all what a battery charger is mate. This is a voltage regulated power supply, a battery charger is, at bare minimum, a 3 stage (constant voltage, constant current, constant voltage) charger. There are many reasons why a dedicated charger is better. This guy has posted a video relying on a potentially fatal fail-safe built into batteries in the case that a battery charger fails. Leaving you with a single fail-safe (battery BMS) which are very cheap to say the least, which, if fails, will result in a lithium fire! A very ferocious type of fire. This guy is insane for not knowing what he is doing, and then posting a video showing other people how to charge lithium batteries on the cheap without discussing the dangers.
Finally good advice for LFP cells . Yes keep the output under 14.6v for 4 cells to avoid clogging the SEI layer and slowly but irreversibly reducing capacity. I have one for 5 volts that can be brought down to 3.65 volts with a DC to DC converter and similarly a 24v version that can be increased to 29.2v for an 8S string.
This is not a good way of charging a lifepo4 or even lead acid, it will put very heavy strain on the mosfets as it's delivering everything it can, I expect the psu to fail very soon you have to have a constant current and constant voltage module or cc/cv then adjust until you get a steady 20ah out regardless of how drained or full the battery is and I think 14.1v is a better voltage for the absorption process, I'm still testing to determine that one
@@jovetmaniebo3904 could be anything, does anything look blown? Any burn marks missing components? You need a cc cv regulator or forget doing it this way
as someone else said "That's just a power supply, not a battery charger. There is nothing to limit the current or stop the charge when the battery is full." that is a reasonable point which how will that stop?
@@electronicsNmore Thanks I was curious on this. So even if you leave it plugged, the BMS on the battery would automatically limit the draw from the power supply supply efffectively protecting the battery right?
@@electronicsNmore thats not true. The BMS doesn't do that. What slows the current is a combination of 2 things. 1 the internal resistance of the battery increases as there is less chemistry available to charge the battery. And the other reason is the lower voltage difference between the battery and the charger. Please what you are doing is dangerous. Relying on these BMS systems is a bad idea. They are meant to stop over volting the cells and causing fires, not for being the limit for charging the batteries. At the very least leaving one of these charging will damage your battery! A battery is absolutely 100% charged when the current reaches 0.5A at 14.7V even left at 14.6V until the current goes under 0.5A will cause damage.
No it will still trickle charge the battery. Lithium batteries do NOT like being at 100 percent all the time unlike lead acid. I recommend shutting it off at 90 or having it on a timer or relay
Hi from uk. I cant find a 30a. I have two agm 120ah=240. Im thinking of getting the 50a. To much for my needs. Can i adjust the voltage and measure the amps with my meter then mark the aduster when im at 30a. I rarely go below 12.2v but im also thinking of another marker at 15a to slow charge before the 30a bulk. Ill be using my genny 2200w early am for about 45 minutes and watching the amp meter on the charger. Hope fully after the bulk charge the solar mppt will float it during the rest of the day. Am i on the right track? Oh when switched on do you see the volts then it switches over to the ampage. Regards, Ray.
Really nice setup, and well explained.👍 I would like to have similar, but with an output to match requirements of my 48V e-bike battery. The stock charger takes it up to 100%, and I'd rather see it peak at 90% or so to prolong battery life.
Exactly You can use any p/s not too much above your pack voltage if you have a bms. (Most server power supplies are engineered to support wiring multiple units together in parallel or series. And they are dirt cheap.) If you don't have a bms, YOU are the bms. I believe what he's showing is a DROK. They also make a 60v 10A model. You won't get 10a at 60v. At 50.2 you'll get about 8 amps. Without a bms, cell voltages will start to creep, and you'll get a voltage for the combined pack of 50.2, bit it will be some cells at 4.2, some at 3.9, some at 4.5.... If you're going to be charging with odd ball chargers, a bms and an active balancer are highly advised. You can get a bms with the feature baked in, or you can get a separate balance board. You can get an inexpensive 6S charger that will active balance while charging half your pack for about $40.
I purchased one of these about a month ago from aliexpress and it just came in a few days ago. I hooked it up and although I got the 30a version, it pushed 42a (I set the voltage at 14.4 for my lifep04) and began to smoke after about 10 seconds. I was monitoring the voltage and it stuck exactly at 14.4 on the output terminals. I unplugged the unit quickly and it still works, but it seems there is nothing limiting the max current. I hooked it up to a different lifep04 battery I have which was near full, and the psu current tapered all the way from 10a which was what it was when I plugged it in, to 0.5a within about 30 seconds. So the current does taper down at least on my unit. I hope I got a defect and my max current limiter is either broken or missing because they are sending me another one. I did charge some SLA batteries fine with it as the SLA chemistry has a much higher resistance and will not take nearly as many amps as a similarly sized lifep04.
Hello Kevin. If that happens, a simple way to avoid the problem is to set the output voltage to 13.8v to 14V for the first 30 mins to 1/2 hour, then set at 14.5 to 14.6V. My unit does not go that high when the battery is low in voltage, strange.
Nice one! The Voltage can be controlled but the current is 30A anyway? My LiFePO4 battery says charge 5amps (recommend) 10A max! Should I buy the 15V - 5A option? Sorry if it is a silly question, thanks mate!
I was thinking you'd have to be careful not to overcharge the battery, but the BMS of the battery should take care of that, correct? I have a 24v DIY LiFePO4 and need an option to charge it in my van via shore power (invertor does not have built in charger, oops). I was thinking I could add a 24v version of this between a standard shore power connector on the outside of the van and the battery inside. Does this sound logical to you? Thanks for sharing all your projects. Very helpful many times over...
Another good source for AC power wires is electronics recyclers or thrift stores. I got 3 heavy duty 14 ga. AC power wires for $3 plus tax at RePC in Seattle.
I just bought this today because of your video! However it sais its only 220v. I hope I am able to switch it as I got the 12v 40A version and it never gave me an option for 120 or 240
Okay, total novice question; If I have an "Overkill 12v 120amp BMS", can I use 4 of these and connect them in parallel for 120 amp at 14.4v output or would that risk damaging some components?
What happens if my bms doesn't have over charge protection and i bump the potentiometer (or the voltage regulation just fails in this cheap power supply) and now the power supply is giving 15V? I will have no way of knowing. Will my battery explode in a crazy fireball? The answer is, almost definitely. Yes.
Excellent video. I am definitely going to make one of these chargers for my self. Question, why didn’t you go for the 40A power supply for just $10 bucks more? Thanks!
i bought the 40 amps one but when i charge, the amps goes from 7 amps to 20 amps(and its rarely stay long at 20 to 24 amps amps) and i dont now why since it suppose to charge at 40 amps.Does anyone have this problem?
Wow, impressive as always. How else do people charge those batteries? Solar? Shore power? Also, can someone use this setup to charge the battery, and use an inverter to power various appliances/electronics if not using solar? Thanks for your very specific instruction.
Usually connected to solar panels with a charge controller that keeps the voltage being supplied to the batteries at or just below 14.6V if using LiFePO4 batteries. Thanks for watching!
What does this do if the battery voltage is greater than the defined output voltage? (i.e. I charged the battery elsewhere.) Does it damage the unit, or does it just turn off temporarily until the battery voltage lowers?
Glad you liked the video. Too much work would be involved in a long-term test for the HQST battery. Ideally I would want to discharge it at least 4-5 times per week and see what the capacity rating is after a year.
This is awesome. My battery chargers for lifepo4 have been giving only a 13.9 - 14.0v and 15A charge. When I contacted support they said the voltage was controlled by the battery BMS? After a year, do you still recommend this charger?
Definitely need to put a diode on this power supply if you intend to keep it connected but off, as it was not designed to prevent back feed from the battery.
It is designed to prevent back feed. Once the ac mains power supply is switched off and the battery is still connected it runs the fan and nothing else. Been using one of these to charge my batteries for over a year now with zero issues.
Seems like this charger gets an override from the LiFePo battery's onboard bms to trim the input amp rate, is that correct? Or does the charger have some sort of feedback and does that amp drop on its own? I just checked my 24v 14.6A SMPS which is the exact same form factor, alum. case, fan, etc (essentially same wattage w/dbl volts & 1/2 amps) and it also has the voltage adjustment but I don't think there is any feedback circuitry.
Great video. Is there any good reason not to go with the 50amp unit? I mean I feel guilty spending only $22 for a great charger, and feel the need to shell out at least $40.
The charger is capable of supplying 30 amps however the process of how many amps is delivered is mostly based on the state of charge before you even connect the charger to the battery. The battery will take as much current as the charger can supply if it is very low on a charge however the battery would rapidly develop what is called a Surface Charge on the plates as the rapid current is applied. The surface charge is the primary reason almost any low battery will quickly reduce the number of amps as the surface charge is in direct opposition to the charger voltage. They are basically in a stalemate position until things stabilize. In other words , Don't Worry Be Happy ! Listen to Bob Marley . Nick , NavyBlueSmoke ,LST-1195
Why dont u put one of those cheap blue 30a solar charge controllers u see on ebay for $10 on it for safety? Put the power supply of the solar input and hook up the battery to the battery storage terminal.
do you comment on other video sites and do you benefit more if watched on the other site like odysee? Also you give good details in the video but would have liked to see an image inside to see how you did the switch but you stated it well, but isnt the black wire the ground?. ;) I assume you got the 12v 30amp one on the link.
Odysee is a waste of my tiime, there's no money to be made. The switch has two black wires attached to it, one goes to the power cord hot and the other goes to the terminal marked wth the letter L. No, in the video I showed you it's 15 volt 30 amp.
Nice vid! What is the name of the copper plate connecting the screws on the output section? Also, my wires are getting really hot at the beginning, and then cool down when near full charge.
I think you mean are these suitable to charge LiIon . Indeed they are . If you have 4 Li Ion cells in series the maximum voltage is therefore 4.2 volts times 4 cells - 16.8 volts. So you need to buy a DC to DC converter also to up the voltage or buy a higher voltaged unit and drop the output voltage. I would suggest if you want the Li Ion cells to last stop charging at 4.1 volts or less . Even 4 volts .This will extend the number of cycles many times more than what you get at 4.2 volts cut off.
Will Prowse recommended 13.6V for the PSU rated at 10amps. This is because LFP "float" charges at that voltage correct? The only downside is the slower charging current correct? Or can I just set 14.4 an d trust the BMS each time to slow the current?
This can't truly be described as a Lithium Iron Phosphate battery charger as those battery chargers have at least a bulk phase, absorbtion (lower current, within which the BMS top balances) and then either cut off or float depending on battery manufacturers recommendations. This is just a high amperage adjustable volage psu and shouldn't be passed off as a charger. This will perform a bulk stage charge only and stress the BMS if it is left connected beyond 90% SOC.
Works perfectly, used over and over. The BMS is doing all the work, the PSU simply supplies 30A @ 14.65V. If you're worried about stressing the BMS, then use a slightly lower voltage setting of 14.4 - 14.5v.
The charger will magically provide the correct current curve all the way up. And, do explain the 'stress' on the BMS... the BMS can wrangle the max charge and discharge current when used at the limits all day every day... what possible stress is it subject to? Do tell.
@@babylonfive The 'charger' in this case does not correct anything it pushes out a constant 30 amps The LFP cells have low internal resistance so suck up those amps. The Bms function during charging is to completely switch off the current to any individual cell at risk of overvoltage. An intelligent LFP charger tapers the current as the overall SOC is approaching 100%. The BMS Mosfets will do the rest but they are required to only switch a low current when supplied by an intelligent charger but a full 30 amps when supplied by this power supply. This will put more stress on the Mosfets Biggest failure on LFP batteries is the BMS. Why spend hundreds on LFP batteries and then put a cheap power supply across them with cheap components and regulation? Would you pick a cheapo psu for your high end PC, or even worse one that wasn't really designed to power your PC in the first place?
@@garywaite6963 these PSU units do taper amperage... and most people that want to cycle past 4 or 5k cycles will limit their SOC to around 90% and never drain past the last 10%.
@@kevin83FL Don't see how as they're a PSU not a charger Maybe with a lead acid battery as the internal resistance goes up you'll see tapering. I had a Schaudt Ebl100 in my motorhome, basically a PSU, Distribution unit and Fusebox combined. The internal PSU didn't ever taper at over 90% SOC charge when I swapped AGM for LiFePO4. Different story with the original AGM battery. Why should they taper unless the load resistance goes up? They are not intelligent chargers.
How does it limit the current? Does it go into current limit of 30A or it goes into fold over shutdown? Do you have a way to find out? I saw some on these with adjustable Voltage and Current. BTW, good video.
When connected to a fully discharged or partially discharged battery, the output current level will be around 30 amps. The LiFePO4 BMS starts cutting back the flow of current as the battery nears full charge. When fully charged, the input current will be extremely low.
Re: 100 amp BMS Lithium Iron Phosphate battery NEw Dear Sir, I got a 30 amp power supply from Amazon , I set the potentiometer voltage to 14.6 volts as recommended . During the charging stage i measured and i got 35 amp and 13.6v on a volt-amp meter . Is that normal for a 30 amp power supply having an extra 5 amp. ? ? after 3 hours the BMS detected a full charge and 0 amp on the meter wow! My setup: 30 amp ps $20 Weize 100 amp lipo BMs $430 10 gauge wire with 30 amp fuse
same happen to my setup. im charging my 100Ah lvtopsun lifepo4 battery and my current draw reach 42A. i have been using this power supply almost 1.5 months and now i think my dc power supply was damaged because right now my dc power supply only output less than 1.5A - 17w of power.
if im planning to buy a new higher dc power supply like 42A model, will be the current draw of my battery will be the same as 42A for 30A model or it will reach to 52A for a 42A dc power supply model? the problem with this kind of dc power is that it doesn't have adjustable current output and it using dc power supply higher that in its rated current output.
The saving magic is the built-in BMS of the battery. If you don't have a Battery Management System (BMS) built in to your battery, DO NOT USE THSI METHOD!
No, you are incorrect. The unit consists of a charger to an exact voltage that matches the highest acceptable voltage for that class battery, so it can't over charge it even if the BMS didn't work. The BMS would disconnect once any one cell goes over 3.65V, so there's no way that a working BMS would allow damage. Consider reading more about how batteries and BMS's work before making such comments.
@@babylonfive A battery charger = A power supply + a charge controller. Thats why battery chargers for LiFePO4 do not cost $25. So while a BMS can and will cut off the charge, they are not meant to be the charge controller. A charge controller is meant to be a charge controller
Nothing scary about it. If the BMS is any good, there won't be any problems. You do realize many Li-Ion and LiFePO4 12V batteries are sold for automotive/marine use? Clearly there's no issue with the alternator supply high levels of current.
@@electronicsNmore a BMS is designed to manage the exceptions to the rule. As in, the occasional over voltage protection. They are not designed to manage the rule. As in, every time you charge, especially if you cycle the batter often. Thats why a battery charger = power supply + charge controller. I do not image as a once and a while charge increaser (not battery charger😁) a bare power supply would be fine. We did not see the entire charge increase process on video for obvious reasons, what was the approximate time between full amperage and tail off to zero?
@@MikeJordanUnCamplicated Its clear you don't understand what a charge controller does, as you are overglorifying the concept. A charge controller for nearly all chemistries simply takes a constant current charge profile, then a constant-voltage one, and the delta between those voltages always causes the correct current to flow until the battery is charged and cuts off. Some batteries will just keep eating the charge and need a time cutoff, but this isn't the situation with lithium-iron-phosphate, lithium-ion, etc. Your choice if you want to use belt and suspenders and get all twitchy, but it doesn't justify your original comment. Maybe a nice question about limitations of more straightforward charger regimens, and what little benefit a (wait for the clouds to part and heavenly light to beam down, on... to...) charge-controller might bring. That might have been more reasonable.
that looks like a std psu not specifically a charger.charging will work but there is no control to stop charging.so cooking your lead acid thats got no bms real possibility
@@electronicsNmore Most lead-acid batteries don't come with a BMS. Do they make after market BMS's for lead-acid? I've only heard of a BMS for LiFePo4.
Hope the video saves you money! If you're going to charge Lead Acid batteries, set the output voltage between 13.8V & 14.2V. Always charge in a cool, shady area. To be safe, place the power supply on a concrete or tile floor. The PSU simply supplies a maximum output of 30-31 amps @ the voltage you set, the BMS, if it's any good, is what handles the charging and tapers off the current as the 12V battery nears full charge. If you're concerned about "stressing" the BMS, then the solution is simple, use a lower charging voltage of 14.4 to 14.5V, doing so will also extend the cycle life of the battery. Thanks for watching
Is the chager capable of CCCV charging ? because thats a concerne when using a fixed voltage power supply
That is exaclty what I wanted to say.. this needs a Current control pot.. which I think it can be done by taking one small dc-dc module which have cc and adapt the control part to this power supply.
@@cgmarch2359 No need for it, the PSU output based on my tests is limited to around 30-31A. All you have to do is set the correct output voltage, and the BMS if it's any good, will take care of the charging and stop the flow of current as the battery nears full charge.
This is in fact a CV-FloatCharger and setpoint (charge voltage) is limited to 14.65v in this case. You ofcourse can charge also @ true float voltage lead acid eg @ 13.4v.
CV-FloatCharging = CC/CV.
@@electronicsNmore " if the BMS is any good". Nice way to relinquish any responsibility.
A few people have raised extremely valid concerns below. Being, it doesn't stop charging. it will keep pumping in current, even if it drops down below half an ampere. Most battery chargers will stop the charging process at 0.5 amps, but this will not. The problem with that is, BMS's built onto most 12V batteries are primitive and will prevent over voltage charging to prevent battery fires. But relying on the batteries BMS, charging right up to that point every time will definitely cause irreversible damage to your battery. What you need to add to this setup, is a relay and an automatic low current (0.5A) off switch to prevent serious damage to your battery... and if you value your power supply, maybe consider over current protection too.
One point that no one has raised is the charge current when the battery is under 30% charged needs to be limited (especially for batteries under about 120ah). This is usually accomplished by 3-stage chargers, by limiting the charge voltage (3 stage = constant voltage , constant current, constant voltage) the absolute gold standard and bare minimum requirement in charging 99% of batteries. Over currenting batteries with less than 30% charge is crazy damaging to any battery.
If you really want to use this cheap method, there is a safe way to do it...
Typically you need to know the C rating of your battery. Or at least the maximum charge rating in amps. Then choose a power supply that will taper the voltage to maintain the integrity of its max current. Then choose a power supply whos maximum current that is 10 to 30% of your batteries maximum current rating.
The other thing you must do is also set the voltage for lithium to about 13.4 - 13.6V. You might only reach 95% charge but you won't F your battery either by (slightly) overcharging it.
This will ensure you don't destroy your batteries too fast.
Another thing, don't believe what this guy says about the magic he believes about what a BMS does. A BMS will not assume you have hooked up a random power supply to it. Its certainly not smart enough to regulate current. The reason the current falls, is due to the nature of the chemistry within the battery changing as it is becoming closer to being fully charged.
The BMS will balance-charge the cells at a very slow rate, it will protect (with on/off ONLY state mosfets). It will never regulate voltages or currents. It will only completely STOP fire-causing voltages or currents. It WON'T stop you from destroying your battery.
Another good idea is to get a cheap solar pannel lithium charger and use that in conjunction with this power supply. Just use the power supply at 15V and plug it into the solar pannel input on the solar charge controller. 95% of your problems (5% still being exposed high voltage) solved.
hello there i need some help, i have about 16s 24v 512ah ,i just did the setup with headway cells so which configuration do i look our for or do i need more than one charger?
This is very well explained for safety and longetivity of the batteries, yeah safest way is run it through the SCC and let the SCC take control, cheers!
Noticed the guy never responded to your concerns. I have one of these power supplies and was interested in using it as a charger for my LifePO4 battery. I suppose I could just stop the charger manually when it hits 14.6 volts which require constant monitoring.
@@philc.9280 Or buy a simple voltage cut off module board I'm sure they are cheap
Does current flow when voltages are the same? I think it doesnt
After watching your video, I purchased one. It took about two weeks to arrive. I just finished wiring it up and am charging a 200 amp hour system of two 100 amp hour LiFePO4 batteries that are wired up in parallel. It is working great! Perfect! Just what I wanted and for only $25. Thanks for posting this video!
I run three of these in parallel to throw 62.5 Amps in to my 120 AH lifepo4 battery. Always check the output with a multimeter before charging, only takes a second but is a good thing to do so you don't accidently fry your batteries or BMS.
You did it again! Very innovative and informative. This will definitely be a benefit for lots of viewers. Great job!
Glad you enjoyed the video Jon!
I really like when manufacturers will strip a product down to just a metal box with a terminal strip to sell it to me for the least possible
Agree. I see 30A LiFePO4 chargers selling for outrageous prices, $150 or higher.
Not at all what a battery charger is mate. This is a voltage regulated power supply, a battery charger is, at bare minimum, a 3 stage (constant voltage, constant current, constant voltage) charger. There are many reasons why a dedicated charger is better. This guy has posted a video relying on a potentially fatal fail-safe built into batteries in the case that a battery charger fails. Leaving you with a single fail-safe (battery BMS) which are very cheap to say the least, which, if fails, will result in a lithium fire! A very ferocious type of fire. This guy is insane for not knowing what he is doing, and then posting a video showing other people how to charge lithium batteries on the cheap without discussing the dangers.
Finally good advice for LFP cells . Yes keep the output under 14.6v for 4 cells to avoid clogging the SEI layer and slowly but irreversibly reducing capacity. I have one for 5 volts that can be brought down to 3.65 volts with a DC to DC converter and similarly a 24v version that can be increased to 29.2v for an 8S string.
I was just looking for a cheaper way to charge LiFePo4.
Thanks for the tip !
👍
I don't think you're going to find a cheaper way. Thanks for watching!
Server PSUs are great for this too. Can be had for ~10$, just isn’t as straightforward as these supplies are to set up.
Another terrific video! Thank you for the amazing review!!
Glad you enjoyed it! Looking forward to your new video today.
This is not a good way of charging a lifepo4 or even lead acid, it will put very heavy strain on the mosfets as it's delivering everything it can, I expect the psu to fail very soon
you have to have a constant current and constant voltage module or cc/cv then adjust until you get a steady 20ah out regardless of how drained or full the battery is and I think 14.1v is a better voltage for the absorption process, I'm still testing to determine that one
@@cjdelphi Still working fine.
@@cjdelphi my psu failed already. now it didn't output any current higher than 1.5A or 17Watts of power. do you think it just cause by damaged mosfet?
@@jovetmaniebo3904 could be anything, does anything look blown? Any burn marks missing components?
You need a cc cv regulator or forget doing it this way
Just ordered one of these the other day thanks for the vid this is exactly what I want to do with mine....
as someone else said "That's just a power supply, not a battery charger. There is nothing to limit the current or stop the charge when the battery is full." that is a reasonable point which how will that stop?
The BMS stops the charge, as I proved using it multiple times charging both 12V LiFePO4's shown in this video.
As usual, a very informative video from eNm! That looks like a great charger. Thanks! 👍👍
You're welcome Steve!
Would love to see a lead acid battery winter storage / upkeep when not in use. Would be pretty educational
Looks like a nice charger at a nice price. Thanks for sharing my friend.
You can't beat it for the low-cost. Thanks for watching!
Hello
Does it have auto cut off when fully charged or BMS protects over charge protection? Thanks
Nice, inexpensive solution, but might be advisable to use some sort of timer on the ac side to turn it off automatically?
Not necessary. Once the BMS detects full charge, the current drops to a trickle. :-)
@@electronicsNmore Thanks I was curious on this. So even if you leave it plugged, the BMS on the battery would automatically limit the draw from the power supply supply efffectively protecting the battery right?
@@electronicsNmore thats not true. The BMS doesn't do that. What slows the current is a combination of 2 things. 1 the internal resistance of the battery increases as there is less chemistry available to charge the battery. And the other reason is the lower voltage difference between the battery and the charger. Please what you are doing is dangerous. Relying on these BMS systems is a bad idea. They are meant to stop over volting the cells and causing fires, not for being the limit for charging the batteries. At the very least leaving one of these charging will damage your battery! A battery is absolutely 100% charged when the current reaches 0.5A at 14.7V even left at 14.6V until the current goes under 0.5A will cause damage.
I like those cheap supplies too, but dont leave them unsupervised, unless area is fireproof.
Always charge in a cool shady area and place the PSU on a hard surface like concrete or tile.
@@electronicsNmore Cinder-blocks that are vertical work really well, not too portable though
I would assume this unit will just charge and charge until the BMS inside your battery cuts it off?
No it will still trickle charge the battery. Lithium batteries do NOT like being at 100 percent all the time unlike lead acid. I recommend shutting it off at 90 or having it on a timer or relay
Hi from uk.
I cant find a 30a. I have two agm 120ah=240. Im thinking of getting the 50a. To much for my needs. Can i adjust the voltage and measure the amps with my meter then mark the aduster when im at 30a. I rarely go below 12.2v but im also thinking of another marker at 15a to slow charge before the 30a bulk. Ill be using my genny 2200w early am for about 45 minutes and watching the amp meter on the charger. Hope fully after the bulk charge the solar mppt will float it during the rest of the day. Am i on the right track? Oh when switched on do you see the volts then it switches over to the ampage.
Regards, Ray.
I thought a lithium charger needs to be constant-current constant-voltage. Does this charge have that? How how did you know it did?
Really nice setup, and well explained.👍 I would like to have similar, but with an output to match requirements of my 48V e-bike battery. The stock charger takes it up to 100%, and I'd rather see it peak at 90% or so to prolong battery life.
You should be able to find a SMPS with slightly lower output voltage. Thanks for watching!
there are 48V psu available they are rather cheap. just make sure your battery has a bms
Exactly
You can use any p/s not too much above your pack voltage if you have a bms.
(Most server power supplies are engineered to support wiring multiple units together in parallel or series.
And they are dirt cheap.)
If you don't have a bms, YOU are the bms.
I believe what he's showing is a DROK.
They also make a 60v 10A model.
You won't get 10a at 60v.
At 50.2 you'll get about 8 amps.
Without a bms, cell voltages will start to creep, and you'll get a voltage for the combined pack of 50.2, bit it will be some cells at 4.2, some at 3.9, some at 4.5....
If you're going to be charging with odd ball chargers, a bms and an active balancer are highly advised.
You can get a bms with the feature baked in, or you can get a separate balance board.
You can get an inexpensive 6S charger that will active balance while charging half your pack for about $40.
I purchased one of these about a month ago from aliexpress and it just came in a few days ago. I hooked it up and although I got the 30a version, it pushed 42a (I set the voltage at 14.4 for my lifep04) and began to smoke after about 10 seconds. I was monitoring the voltage and it stuck exactly at 14.4 on the output terminals. I unplugged the unit quickly and it still works, but it seems there is nothing limiting the max current. I hooked it up to a different lifep04 battery I have which was near full, and the psu current tapered all the way from 10a which was what it was when I plugged it in, to 0.5a within about 30 seconds. So the current does taper down at least on my unit. I hope I got a defect and my max current limiter is either broken or missing because they are sending me another one. I did charge some SLA batteries fine with it as the SLA chemistry has a much higher resistance and will not take nearly as many amps as a similarly sized lifep04.
Hello Kevin. If that happens, a simple way to avoid the problem is to set the output voltage to 13.8v to 14V for the first 30 mins to 1/2 hour, then set at 14.5 to 14.6V. My unit does not go that high when the battery is low in voltage, strange.
What would you suggest to power a 24s 105ah battery pack??
Nice one! The Voltage can be controlled but the current is 30A anyway? My LiFePO4 battery says charge 5amps (recommend) 10A max! Should I buy the 15V - 5A option? Sorry if it is a silly question, thanks mate!
I was thinking you'd have to be careful not to overcharge the battery, but the BMS of the battery should take care of that, correct? I have a 24v DIY LiFePO4 and need an option to charge it in my van via shore power (invertor does not have built in charger, oops). I was thinking I could add a 24v version of this between a standard shore power connector on the outside of the van and the battery inside. Does this sound logical to you? Thanks for sharing all your projects. Very helpful many times over...
Thank you sir ! Me n my mom going to order this power supply 😊
You're welcome! Thanks for watching!
When did your house burn down?
Another good source for AC power wires is electronics recyclers or thrift stores. I got 3 heavy duty 14 ga. AC power wires for $3 plus tax at RePC in Seattle.
Junk yards are great too 😊
I just bought this today because of your video! However it sais its only 220v. I hope I am able to switch it as I got the 12v 40A version and it never gave me an option for 120 or 240
Okay, total novice question; If I have an "Overkill 12v 120amp BMS", can I use 4 of these and connect them in parallel for 120 amp at 14.4v output or would that risk damaging some components?
What happens if my bms doesn't have over charge protection and i bump the potentiometer (or the voltage regulation just fails in this cheap power supply) and now the power supply is giving 15V? I will have no way of knowing. Will my battery explode in a crazy fireball?
The answer is, almost definitely. Yes.
Excellent video. I am definitely going to make one of these chargers for my self.
Question, why didn’t you go for the 40A power supply for just $10 bucks more? Thanks!
i bought the 40 amps one but when i charge, the amps goes from 7 amps to 20 amps(and its rarely stay long at 20 to 24 amps amps) and i dont now why since it suppose to charge at 40 amps.Does anyone have this problem?
Wow, impressive as always. How else do people charge those batteries? Solar? Shore power?
Also, can someone use this setup to charge the battery, and use an inverter to power various appliances/electronics if not using solar? Thanks for your very specific instruction.
Usually connected to solar panels with a charge controller that keeps the voltage being supplied to the batteries at or just below 14.6V if using LiFePO4 batteries. Thanks for watching!
Now how do you get it to turn on and off according to the battery level
That shit might blow up. I feel more comfotable with a commercial one.
It will fizzle out if it's in correct polarity, no warranty after that. Best to hard wire it.
Thanks for the Information.Great Reviews.Electric 🚹.
You're welcome!
What does this do if the battery voltage is greater than the defined output voltage? (i.e. I charged the battery elsewhere.) Does it damage the unit, or does it just turn off temporarily until the battery voltage lowers?
Great review! I liked the idea of installing a switch(any type) to turn the PSU on/off.
Any plans on a long term review of that HQST? LiFePo4 battery?
Glad you liked the video. Too much work would be involved in a long-term test for the HQST battery. Ideally I would want to discharge it at least 4-5 times per week and see what the capacity rating is after a year.
This is awesome. My battery chargers for lifepo4 have been giving only a 13.9 - 14.0v and 15A charge. When I contacted support they said the voltage was controlled by the battery BMS? After a year, do you still recommend this charger?
BMS do not talk to charger. it will only disconnect the charger once it reaches set voltage/temp for individual cells threshold in the BMS.
Definitely need to put a diode on this power supply if you intend to keep it connected but off, as it was not designed to prevent back feed from the battery.
I'm just going to have mine hooked up in line with an anl fuse holder and when im ready to use I'll just insert the fuse
It is designed to prevent back feed. Once the ac mains power supply is switched off and the battery is still connected it runs the fan and nothing else. Been using one of these to charge my batteries for over a year now with zero issues.
Seems like this charger gets an override from the LiFePo battery's onboard bms to trim the input amp rate, is that correct? Or does the charger have some sort of feedback and does that amp drop on its own?
I just checked my 24v 14.6A SMPS which is the exact same form factor, alum. case, fan, etc (essentially same wattage w/dbl volts & 1/2 amps) and it also has the voltage adjustment but I don't think there is any feedback circuitry.
The BMS does all the work. When the BMS senses the battery is near full charge it automatically tapers off the current.
if you didnt have a bms you just made a potential bomb
Nice one believe I'll invest in those always need spare lights. 🙂
Great video. Is there any good reason not to go with the 50amp unit? I mean I feel guilty spending only $22 for a great charger, and feel the need to shell out at least $40.
As long as your battery c rating can handle the current I dont see why not. I got a 40 amp cause my c rating is 50 amps
@@SpeakersIsGod great info, thank you.
Will that work for 70ah agm car battery ? Wouldn't 30 amp overheat and damage the battery?
The charger is capable of supplying 30 amps however the process of how many amps is delivered is mostly based on the state of charge before you even connect the charger to the battery. The battery will take as much current as the charger can supply if it is very low on a charge however the battery would rapidly develop what is called a Surface Charge on the plates as the rapid current is applied. The surface charge is the primary reason almost any low battery will quickly reduce the number of amps as the surface charge is in direct opposition to the charger voltage. They are basically in a stalemate position until things stabilize. In other words , Don't Worry Be Happy ! Listen to Bob Marley . Nick , NavyBlueSmoke ,LST-1195
I connect the battery, and the power led illuminates and the fan runs, even though the mains power is off. Is that normal, and ok ?..
Sounds like an over heat protector when switched off, a capacitor.
Is there any particular reason you did the charge test outside and not inside?
Less work. LOL.
Why dont u put one of those cheap blue 30a solar charge controllers u see on ebay for $10 on it for safety? Put the power supply of the solar input and hook up the battery to the battery storage terminal.
I don't think that would limit the current as it thinks the input is a solar panel, the safest way is a cc cv module
do you comment on other video sites and do you benefit more if watched on the other site like odysee?
Also you give good details in the video but would have liked to see an image inside to see how you did the switch but you stated it well, but isnt the black wire the ground?. ;)
I assume you got the 12v 30amp one on the link.
Odysee is a waste of my tiime, there's no money to be made. The switch has two black wires attached to it, one goes to the power cord hot and the other goes to the terminal marked wth the letter L. No, in the video I showed you it's 15 volt 30 amp.
Nice vid! What is the name of the copper plate connecting the screws on the output section? Also, my wires are getting really hot at the beginning, and then cool down when near full charge.
You must be using wires smaller than 10ga.
@@electronicsNmore Ordered some stranded 10 gauge. What is the copper plate on the Out screws called?
@@jusphit I believe he just cut them out of a copper strip.
Nice can you also build a cheap Li-ion charger with 20 amp.+?
It doesn't pay to build one when these are so cheap. Thanks for watching
I think you mean are these suitable to charge LiIon . Indeed they are . If you have 4 Li Ion cells in series the maximum voltage is therefore 4.2 volts times 4 cells - 16.8 volts. So you need to buy a DC to DC converter also to up the voltage or buy a higher voltaged unit and drop the output voltage.
I would suggest if you want the Li Ion cells to last stop charging at 4.1 volts or less . Even 4 volts .This will extend the number of cycles many times more than what you get at 4.2 volts cut off.
@@aprilsteel9466 START charging at 4.1 or less is what I think you meant to say
What is the efficiency of this power supply?
I tested it at 75-80%. Same setup.
Great thanks for sharing
You're welcome Ed!
Will a 20A power supply work?
The lower the amps, the longer it takes to charge. What ever you want as long as it doesn't exceed the c rating
Why wouldn't this setup burn up the power supply if the bms charging circuit is 100 amps?
The power supply appears to have the current output limited.
Will Prowse recommended 13.6V for the PSU rated at 10amps. This is because LFP "float" charges at that voltage correct? The only downside is the slower charging current correct? Or can I just set 14.4 an d trust the BMS each time to slow the current?
I have a modification that I made to this charger which I'm going to be showing soon and another video.
@@electronicsNmore Great, thank you! 👌
This is just a power supply not a charger. This is usually used in a 3d printer
This can't truly be described as a Lithium Iron Phosphate battery charger as those battery chargers have at least a bulk phase, absorbtion (lower current, within which the BMS top balances) and then either cut off or float depending on battery manufacturers recommendations. This is just a high amperage adjustable volage psu and shouldn't be passed off as a charger. This will perform a bulk stage charge only and stress the BMS if it is left connected beyond 90% SOC.
Works perfectly, used over and over. The BMS is doing all the work, the PSU simply supplies 30A @ 14.65V. If you're worried about stressing the BMS, then use a slightly lower voltage setting of 14.4 - 14.5v.
The charger will magically provide the correct current curve all the way up. And, do explain the 'stress' on the BMS... the BMS can wrangle the max charge and discharge current when used at the limits all day every day... what possible stress is it subject to? Do tell.
@@babylonfive The 'charger' in this case does not correct anything it pushes out a constant 30 amps
The LFP cells have low internal resistance so suck up those amps.
The Bms function during charging is to completely switch off the current to any individual cell at risk of overvoltage.
An intelligent LFP charger tapers the current as the overall SOC is approaching 100%. The BMS Mosfets will do the rest but they are required to only switch a low current when supplied by an intelligent charger but a full 30 amps when supplied by this power supply. This will put more stress on the Mosfets
Biggest failure on LFP batteries is the BMS. Why spend hundreds on LFP batteries and then put a cheap power supply across them with cheap components and regulation?
Would you pick a cheapo psu for your high end PC, or even worse one that wasn't really designed to power your PC in the first place?
@@garywaite6963 these PSU units do taper amperage... and most people that want to cycle past 4 or 5k cycles will limit their SOC to around 90% and never drain past the last 10%.
@@kevin83FL Don't see how as they're a PSU not a charger Maybe with a lead acid battery as the internal resistance goes up you'll see tapering. I had a Schaudt Ebl100 in my motorhome, basically a PSU, Distribution unit and Fusebox combined. The internal PSU didn't ever taper at over 90% SOC charge when I swapped AGM for LiFePO4. Different story with the original AGM battery. Why should they taper unless the load resistance goes up? They are not intelligent chargers.
I just recently bought (2) 12v 10ah lithium batteries. Do I need to charge them out of the box - or do they come precharged? Thanks!
They should come at around 50% charged. Fully charge them before use.
@@baneverything5580 Thanks!
How does it limit the current? Does it go into current limit of 30A or it goes into fold over shutdown? Do you have a way to find out?
I saw some on these with adjustable Voltage and Current. BTW, good video.
When connected to a fully discharged or partially discharged battery, the output current level will be around 30 amps. The LiFePO4 BMS starts cutting back the flow of current as the battery nears full charge. When fully charged, the input current will be extremely low.
The charger/psu is already limited. Max power or max amp depending on the charge voltage is already limited. Its a 30A 12v psu.
Its in Spanish (I think), how do I order it of i can't read it?
Copy & paste to online translator
Good in a pinch, but not recommended for 24-7-365.
Re: 100 amp BMS Lithium Iron Phosphate battery NEw
Dear Sir,
I got a 30 amp power supply from Amazon , I set the potentiometer voltage to 14.6 volts as recommended .
During the charging stage i measured and i got 35 amp and 13.6v on a volt-amp meter .
Is that normal for a 30 amp power supply having an extra 5 amp. ? ? after 3 hours the BMS detected a full charge and 0 amp on the meter wow!
My setup:
30 amp ps $20
Weize 100 amp lipo BMs $430
10 gauge wire with 30 amp fuse
Set output voltage a little lower, and you should be fine. 14.4
same happen to my setup. im charging my 100Ah lvtopsun lifepo4 battery and my current draw reach 42A. i have been using this power supply almost 1.5 months and now i think my dc power supply was damaged because right now my dc power supply only output less than 1.5A - 17w of power.
if im planning to buy a new higher dc power supply like 42A model, will be the current draw of my battery will be the same as 42A for 30A model or it will reach to 52A for a 42A dc power supply model? the problem with this kind of dc power is that it doesn't have adjustable current output and it using dc power supply higher that in its rated current output.
The saving magic is the built-in BMS of the battery. If you don't have a Battery Management System (BMS) built in to your battery, DO NOT USE THSI METHOD!
Exactly. The BMS makes it all work.
You are using the batteries BMS to stop charging. No doubt.
Correct, and it works just fine.
A battery charger = Power supply + charger controller. You only have half of the equation here. Would not be my choice. Looks scary to me
No, you are incorrect. The unit consists of a charger to an exact voltage that matches the highest acceptable voltage for that class battery, so it can't over charge it even if the BMS didn't work. The BMS would disconnect once any one cell goes over 3.65V, so there's no way that a working BMS would allow damage. Consider reading more about how batteries and BMS's work before making such comments.
@@babylonfive A battery charger = A power supply + a charge controller. Thats why battery chargers for LiFePO4 do not cost $25. So while a BMS can and will cut off the charge, they are not meant to be the charge controller. A charge controller is meant to be a charge controller
Nothing scary about it. If the BMS is any good, there won't be any problems. You do realize many Li-Ion and LiFePO4 12V batteries are sold for automotive/marine use? Clearly there's no issue with the alternator supply high levels of current.
@@electronicsNmore a BMS is designed to manage the exceptions to the rule. As in, the occasional over voltage protection. They are not designed to manage the rule. As in, every time you charge, especially if you cycle the batter often. Thats why a battery charger = power supply + charge controller. I do not image as a once and a while charge increaser (not battery charger😁) a bare power supply would be fine. We did not see the entire charge increase process on video for obvious reasons, what was the approximate time between full amperage and tail off to zero?
@@MikeJordanUnCamplicated Its clear you don't understand what a charge controller does, as you are overglorifying the concept. A charge controller for nearly all chemistries simply takes a constant current charge profile, then a constant-voltage one, and the delta between those voltages always causes the correct current to flow until the battery is charged and cuts off. Some batteries will just keep eating the charge and need a time cutoff, but this isn't the situation with lithium-iron-phosphate, lithium-ion, etc.
Your choice if you want to use belt and suspenders and get all twitchy, but it doesn't justify your original comment. Maybe a nice question about limitations of more straightforward charger regimens, and what little benefit a (wait for the clouds to part and heavenly light to beam down, on... to...) charge-controller might bring. That might have been more reasonable.
🖖 👍
Cannot see link or brand regrettably
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that looks like a std psu not specifically a charger.charging will work but there is no control to stop charging.so cooking your lead acid thats got no bms real possibility
It is a standard PSU, the BMS is what stops the charging. As the battery near full charge, the current level drops off to near zero.
@@electronicsNmore Most lead-acid batteries don't come with a BMS. Do they make after market BMS's for lead-acid? I've only heard of a BMS for LiFePo4.
Lead acid batteries are easy to charge and don't get damaged easily. Simply set the max charging voltage, and walk away. I use 14V.
first