Glad to hear it helped. I also have another video that answers some questions about these batteries. ruclips.net/video/WKY1-JNijqo/видео.html Thanks for watching, and please share.
Hi, Very carefully followed your instructions. Cut the trace cleanly and completely. Soldered the 51k resistor on the two points indicated. But when I insert the battery into the charger, I still get the red/green flashing lights, and when pressing the button on the battery, all four green LEDs on the battery flash four times. Any recomendations? Thanks
Excellent video. I tore mine apart and noticed the board looks different than yours. There's a large glob of solder closer to the negative terminal. I've tried boosting it enough to get recognized by the charger by charging it at 1amp 31v from power supply, but only get one blinking light and still won't get recognized by the charger. I ordered a DC DC voltage booster and hoping that can do something since I can jump the voltage to 40 or 41v vs the 31 that my power supply tops out at. I saw another comment where you mentioned to check the voltage of each individual cell and balance the cells. How do you do that when this back is assembled in a way where I can't get terminals to the parts of each cell pack that I need to?
The board measures the voltage of all the banks of cells, so you should have access on the board. You may have one of the newer boards that is very different, but all cells should be accessible from there.
Hi, Newbie here and working on to fix my Ryobi 36v, 2.6A lawn mower battery. Since it was manufactured in 2015, I was thinking its time to replace all batteries (since it is not performing well) and I did. After changed, pretty much I am getting 40v at the pcb boards pins. But, when I measure across 2 main terminal point, T1 and T2, I am getting only 16.5v. Is this normal? With this condition, I was able to recharge and use it again but performance almost the same. Is the mosfet failing? Any ideas to fix my problem, please let me know. Thanks in advance.😊
I don't think the mosfet is failing. Those things either short out or stay open, which would cause no power or full power. I would ask where you got the batteries from. Laptop batteries won't work as these ryobi batteries are high current batteries. If they are new batteries, I would test them with a load to see if you were scammed as their are a lot of cell sellers that are not trustworthy. Good luck.
@@thecityviking The batteries might be the cause. I use cheap China batteries but with higher current, 5800mAh each. I assumed it should give me more hours, 11.6Ah 😂, will it?
Bit late question to ask this but idk, My dad has a 40V 5 Ah 180Wh Ryobi battery (Model: OP4050) for a lawnmower, Which was like a entire set that he picked up somewhere on the side of the road, But when it went into sleeper mode we have done everything from going in and out with the charger before it goes back into sleeper mode,
To tring to use the reset terminals (I think that is what it is called). And he thinks its something to do with the "Mof" thingy (atleast what he thinks its called. Idk didnt watch the full video). Any suggestions or?
GREAT video - thank you!! You said, "don't charge these without being attentive", does that mean the charger will/can overcharge using this modification? Any insight you can share about your warning would be appreciated!!
Nice video - I have a later 40v battery so the circuit board looks a little different - at around 9.40 you implied that when you have done the mod you are disabling the charge controller BMS and there is a concern there - what exactly do you mean? Will this result in the charge system not switching off when the batteries are charged?? My battery got left out in the rain, no corrosion but is now only 15.5v and the four green lights. On charge it gets the usual oscillating red and green lights on the charger.
Yes, the mod does bypass the BMS charge circuit and you become the BMS for the battery. Only charge the battery while you are there to monitor it. I hope that clears things up for you. Thanks for watching.
The charger and the battery communicate on the T1 pin. If the battery tells the charger the battery is no good, there is not much you can do to get the Ryobi charger to charge that battery. I have been trying to get an older Ryobi charger to see if I can "hack" it.
My battery's LEDs are all blinking green when I press the button, and the battery won't charge. If I cut the trace connecting the pin and capacitor for the Fet, and then don't solder in a resistor, can I still charge the battery without any problems?
Blinking lights o. Your battery probably means you have an unbalanced pack. You need to check all the individual cell pairs and see if they are all at the same voltage. I would try and charge them equally and see if it charges on your charger first.
For the FET that will not turn on why not just solder a jumper between the Source and the Drain of the FET, this will have the same effect as the FET being turned on using the Gate, but without cutting any traces.
I agree that will work. The reason I decided to cut the trace and tie it to the gate of the other FET is to possibly get some protection. If the pack starts to overheat or overcharge I was hoping the intelligence in the pack may try and shut down the other FET to protect itself. By modding either way you are defeating a safety mechanism that is why I never charge my modded packs unattended.
@@thecityviking That's a safety minded approach and is probably the better idea, but it is based on hope and not fact, but it is the better idea. And any item that is modded without having an accurate understanding of how the mod _WILL_ effect the circuit should always be personally monitored.
Great video, thanks. With this MOD will the original charger work? or do we need a constant 40v? or can I bypass T1 to charge gate to open it and use original charger? thanks
The 2nd option at 10:54 you said, can’t work after the battery is charged with the cover on? If the voltage is above the (30 )threshold doesn’t that mean it will work fine, with the cover on unless the voltage dips below that threshold?
When I have a battery that won't take a charge, I always leave the screws loose that hold the cover on. That way I can easily open it for charging and also monitor individual cells to ensure even charging. The BMS in these batteries seem to lock out charging from the factory charger once they have detected a problem with the cells. The mod I show in this video with the resistor only works on older firmware.
Hello, I must say Great video! You really seem to know your 40v ryobi batteries. Now for my question, I have built a robot from hoverboards and retrofitted a lead acid scooter to both use 40v ryobi batteries. My issue is when using 2 batteries in parallel one of the 2 batteries will be greedy and hog all of the load, thus making the motors over draw the battery and drain it to quickly while leaving the other battery at a full charge. Do you have any idea on how to make them share the load nicely? Sometimes I can get them to share if they are both fresh off the charger and I unplug the one that has the load and apply a load and press the charge indicator button then plug back in the original battery with the load still active. Kind of a convaluted process. I am hoping for a resistive solution. Thanks
I noticed the same problem when trying to power my bike in my other video. I just run on one until dead and then switch. I know this is not a solution, but there is no real easy way to get around this, at least not safely.
That would definitely bypass the FET's, but that could be very dangerous. You would have nothing preventing the pack from over discharge, or over heating. I do not recommend that.
Hello City Viking I have same problem with a Ryobi 36volts 5.0 ah battery it blinkes when i slide in the battery in to the charger after few seconds stop's to blinke and there's no more any other issue than that it's all Dead at not charging not blinke please help me with this battery to fix
Have you opened the battery and checked the voltage of each pair of cells? All of the cells inside should have a voltage that is close to all the others. It could also be your charger. I will be posting another video soon about these batteries and how to check cell voltages. Stay tuned!
@@thecityviking I think you got it because I think I have forget it about that it's been like 6 months ago the charger it bloud a spark lights made this with like a shot because the charger goted spilled some water inside but i didn't think it was it was the charger because it is still working regularly with all the function
I have tired different approaches and cannot seem to get any of my old batteries to come back. I have 11 of them. I am wondering if I should make a battery pack out of them for something else.
I have 20 and plan on making a battery pack. I have some ideas but not sure what final voltage I want. If I make it for my trailer it will either be a 24v or 12v. I may make one for my new bike motor. A 1000W mid drive that runs on 54v
I have a battery that came and it never took charge. I tried the jump reset and it didn't work. I am wondering if this would work. When I try the jump reset method the light for the battery doesn't come on until I press the button and when I do that it stays on, thoughts?
is there a formula or method you used to determine which resistor to use? i'm not clear on how you got there but it's a creative as heck bypass and the resistor idea is fantastic - a second question is - have you seen other batteries use two fets to work in the same way? i'm thinking this is some kind of standard practice - but then i'm not sure why manufacturers would sometimes use only one fet lol so many things to learn.
The gate resistance is not critical for slow switching. Many gate resistors are around 1k and higher resistance will still work but may slow down the switching on of the FET. Since this is just on or off not rapidly switching back and forth I picked a larger value. The formula is something like this. IGPEAK=(VG(on) - VG(off))/(RG+RG(int)). Keep in mind though, that if you go too small, you could kill the FET, or the drive circuit. Often, most BMS circuits I have seen have many FETs, but it is to increase the current they can switch. If you need to switch 100A, you would have to use many FETs to accomplish this. I have never seen a BMS that has seperate charge and discharge FETs like these Ryobi boards. The earlier Ryobi 40V batteries only had one FET, and maybe they found an issue that they felt warranted this. Most BMS circuits have FETs in parallel to increase their current switching, while these Ryobi BMS circuits have them in series. I think they may have done this as an extra safety. FETs can fail as a short or as an open, so to have a runaway short circuit you would have to have 2 FETs fail the same way.
So if the BMS shuts off the discharge FET, then the charge FET is also turned off (since the gates are paralleled). If that happens, how do you turn them back on?
@@thecityviking weren’t you tying the gate of the charge FET to the gate of the discharge FET through a 51K resistor? Given the high gate impedance, it seems this is driving the two gates with the same signal.
Sorry, I read your original post incorrectly. You are correct, the gates are paralleled. The charger does not charge the battery on the newer battery packs because there is communication between the charger and the battery pack. If the pack tells the charger that it is defective, the charger does not provide the charge voltage. I think possibly we need to modify the charger and the battery?
@@thecityviking perhaps so. Unfortunately, I’m not familiar with the details of the circuitry in the charger or the battery. So I have no intelligent feedback on the best way to approach it. You’re probably much further along on ideas for the best way to do that.
got super excited finding your video because im having the same issue w my 6ah 40v op40602 battery crack the case open and competely different board manfacturing date on mine is 2019 4 13 back to the drawing board lol but A+ video man keep up the good work
I have a couple newer batteries, but they both work fine so far. I was thinking of doing another video just talking about these new batteries and how to check them and possible alternative charging.
Hello there . I’m very curious in how I can reduce power curro from 120v to 40v dc my thing is , I want to install direct power to a 40v sunjoe pressure washer to stop using the battery and have direct controlled power to the machine
Hallo. I have 20 V at the + and - terminals. But when i check terminals + and T1 then it is 40V. When I connect electric motor for testing it does not start. What could be the problem??
Sounds like one of 2 possible problems. 1. The FET is damaged and not working and turning on. 2. The signal that is supposed to turn on the FET is damaged or not coming on for some reason. If it doesn't work in a tool, you could try jumpering the FET to bypass it.
I've got an older version of this 40V with the single fett (spelling?). I have 38V from Negative rail to postive terminal. But only 17v from negative terminal to positive terminal. So something in that fett is holding me back?
Thank you VERY MUCH for this fix video....but....what size resistor do I need to order? 1/4 watt, 1/2 watt, 3 watt? (51K ohm of course) Sorry for being an electronics newbie. Your resistor looks a bit small, so I would guess 1/4 watt?
Good question. The resistor I used is 1/4 watt. There is virtually no current through this resistor as it just passes the 10 volts from the one spot to the other to turn on the FET. Make sure you do have 10V at the other side. Good luck.
Basically you are cutting the trace for the gate of the FET and then tying it high to keep it turned on. Remember though that you are bypassing the BMS, and now you have to monitor cells to ensure safe charge/discharge. Thanks for watching.
Hi City Viking. Thanks for the video. Could you please clarify. Is it a faulty FET causing this problem and could I just replace the FET or is there some other issue causing the FET to remain open. One of my batteries gets the blinking light of death on the Ryobi Charger. I've pulled the battery apart and charged it manually through the postive connector and the screw terminal as you showed, but the battery will not charge on the Ryobi charger after manually getting the battery up to full charge. Therefore the problem is not because the battery is too low in voltage. I could cut the trace and apply the resistor as per your video but I could also replace the FET. Is there a way to test the FET while it is still connected to the board to determine if the FET is the problem? Cheers Marty.
It is possible that tour FET is faulty but in my experience it is unlikely. Basically what happens is the intelligence on board determines that the pack is defective and it doesn't allow charging. I will be making another video shortly that will describe how the pack works and why it fails and how to properly check each cell set.
i have a stack of the 1,5A with one mosfet, do you know how to fix them? they show 1 green when i pust the testbuttom, but in the charger it says fully charged. When i put it in a tool it will not run. Any suggestions?
You need to check voltage of the pack and the individual cells. It could be that one of the banks of cells is low, or the whole pack is too low to charge properly. thanks for watching
@@thecityviking Thanks for answer. It has the right voltage when i measure inside (around 37v) but between the + and - terminal its only half the voltage. i can take the - inside from circuit board and it will run a motor.
I wouldn't mess with lithium ion batteries the discharge safety mechanism is there for a reason they can be ticking bombs if not put back together the proper way for the BMS to function
I can not give a definitive answer to that. The Ryobi charger communicates with the battery, and that is what determines weather or not the Ryobi charger will work or not. I have had some luck with the older battery packs working with the Ryobi charger, but no luck with the newer battery packs. Thanks for watching.
You may be able to charge up individual cells on the Mikita to get a little more life from them. Unfortunately I don't have any to play with to know for sure.
I like the switch idea! I cut the trace so that high signal from the resistor mod doesn't feed back into the low signal coming from the rest of the circuit. It could cause more damage to the circuit.
i was trying to solve same issue with bunch of milwaukee M18 batteries won’t charge or flashing light what i need help is to figure out to do the jump cuz there is only one mosfet
Link to your charge board? I can't seem to find any that have a red/green indicator light. Also, is yours able to step up the voltage from something like 12v? Of are you having to power that board with a separate power supply of at least 41V?
I power mine with a 12 power supply from a computer so yes it is a boost converter. I checked my purchase and its not available any more, but I will see about finding a similar link for you. www.droking.com/150W-Power-Supply-Module-DC-10-32V-to-10-46V-16A-Adjustable-Boost-Converter-DC-12V-24V-Voltage-Regulator-Adapter-Charger-Driver
Hello, I have a 40v pack from 2013 with samsung cell in it and measures 42.2v between CL1- & BAT+ terminals. Also I measured CL1- & CL5+ and got 20.5v also CL6 - & CL10+ is giving 21.7v. But actual terminal + & - from the pack is only giving me 20.5v. Btw, Pack charges good and been sitting for a week. Is there anything I can do to revive it? Final note, the tool runs for about a minute or two and dies with battery light still on with 3 green dots and 20v. Thank you
I had a pack like that and it turned out to be a couple bad cells. It was on a pack that had a single FET and when fully charged would run lawn mower for about 2 mins then it would cycle off and on. I bypassed the FET and found that the pack would get hot in one set of cells. That set of cells would be much lower then the rest of the pack. You can not recover the pack but I did salvage individual cells to power other things.
Thank you for the response. That was my initial thought too. And yes, it’s the one with single FET. I guess it’s time for salvage. Btw, I found out that it’s not a AA size. What projects are these cells useful for if you don’t mind me asking? Thank you
@@bbg5939 These cells are lithium Ion and are 3.7V nominal, that do charge to 4.1-4.2v with a proper charger and you can use them in laser pointers, vapes and special torches, most people use them for those things but they can also be used as E-bike or E-skateboard packs, there are other uses like batteries for your solar power storage, but you need a bit more expertise to do that and a ton more batteries. BTW if you let them discharge too low it reduces the cell life, with these cells you're best not to let them get below 2.5V each but charge them when they are somewhere between 2.5 and 3.5V up to say tops 4V (as overcharging at 4.2V+ also reduces their life!) Overcharging and over-discharging Lithium cells is dangerous and can make them explode and set fire to stuff like houses and garages so beware, this is why they have a battery management system to limit the discharge.
Great video on charging.. my bat has just stopped being charged. I may actually get a non Ryobi replacement from eBay and also try to get your screw mod working. What bench power supply do you use for the DC to DC boost converted? I will probably try to use the screw mod 1st and carefully monitor the battery voltage as you say this bypasses the overcharge protection.
@@thecityviking I have 2 chargers, both see the battery as fully charged. Occasionally it shows error when first plugged in but I remove it and slide it back in it shows full. Definitely strange. Also when checking the charge by the button on the end it shows full.
I have bought completely dead ryobi batteries and was able to bring them up to full voltage with no problem. I show how in one of my videos. Good luck with your batteries.
In the video, I talk about this and explain why I don't do this. I tie the gate to the gate of the other FET so the BMS can still shut off the power. Thanks for watching.
I am looking at making another video about a Rev Q board that is in the newer Ryobi batteries. Perhaps that is what you have in your batteries. Coming soon!
hi, I really enjoy your suggestion , but after I opened my batterie, it has a different layout I wish I could send you a picture to see if you have any suggestions how to solve it .
I am looking at making another video about a Rev Q board that is in the newer Ryobi batteries. Perhaps that is what you have in your batteries. Coming soon
Cells may be just drained to 0V. I would try charging individual cells slowly. Start with 1V and 500ma. If it charges to 1V, then try 2. Once over 3V you can try charging quicker.
If you could provide a link to where to an example of the charging device that you are using it could be very helpful to people. Also, you seem to understand this circuitry pretty well. I have a couple of packs whereby I have verified each cell is charged to full voltage, yet I only get half of the voltage at the main terminals. From the main pos and neg charging terminals the pack reads 20.5v and from the main negative terminal to each individual cell I get about 2v even though each cell is charged to 4v. Any thoughts on what is causing the BMS to restrict the pack to half the voltage at the main charging terminals?
From Amazon Yeeco Boost Converter Module DC-DC Step Up Converter Board 8-32V to 9-46V 8A 150W Voltage Regulator Booster Module Adjustable Voltage Step Up Power Supply Module I use a laptop power supply to provide input power.
@@thecityviking Thank you. Any thoughts on the 2nd half of my comment? Also, any idea if we can use the "rst" location on the board to reset the chip? The available pins are: CLK, DAT, GND, 3.3v, RST. I wonder if we would briefly shunt the 3.3v to RST? Now that I have every cell at full charge I am wondering if it is possible to manually reset the chip using these locations on the board?
Sorry I didn't see the second part. I believe I know exactly what you're talking about. The voltage is not being restricted the pack shuts off the FET when the pack is not being used if you hook a small load up to the main terminals and then measure it you should get the proper voltage but it only lasts for about one minute and then shuts off. I will make another video explaining this for others.
Thanks City Viking, great video tutorial, my battery is dead as we forgot to leave it charging last winter, but it's the model with one FET, what would you suggest to do in this case, just desolder the FET completely, force charging it to some charge, then replace the FET and charge normally?
amazon.com link for power supply I use: amzn.to/3hXIysX The link was in the description. It works with an input between 10-32V and has adjustments for voltage and current on the output. Output has to be higher than the input. I use a 12V power supply from and old Computer but you could use a laptop power supply as well for the input. I Don't set the current higher than one amp for safety. Looks like they are currently out of stock but should get more. It's usually under $20. Good luck!
Hi CityViking! I have ryobi lithium pack rated at 36v 4Ah, (model BPL3640). I was told it was shot, but after placing it in a charger it charged to full - indicator shows all 4 lights - it took about 2hours with 1.7A charger. But, when i place it in a tool - it wont start - so i guess i have similar problem as shown in Your video but with discharging. I pop the battery pack open and check all cells - they show good voltage around 4.2V. And when I check battery pack voltages it gives me around 19V between + and -, 40V between + and T1 terminal, and 0V between + and T2. I have got a good pack and when i measure it, it shows 36V between + and - , 36v between + and t1, 36v between + and t2. Can You give some advice where to look? Should i check again each cell or start looking whats wrong on pcb? Where to start? Does this "hack" also work for discharge issues?
Does it need to be specific with the 51K ohm resistor? or can you go the next number up or down? Also instead of the Mod would it be possible to replace the FET with a new one to fix the charging issue? I'm just asking since the Mod does override the Over Charge protection of the BMS. Thanks in advance.
I have had a couple of those single mosfet boards. While you could completely bypass the mosfet, I would not recommend it. If you get all the cells to approximately 3.5V and are fairly balanced, you may be able to charge it, but I have no other advice at this time. Thanks for watching, and check out my other video if you haven't seen it yet. ruclips.net/video/WKY1-JNijqo/видео.html
@@thecityviking thanks for replying. When I tested the voltage across the battery (not from the contacts) it gives me a 39.25 V but the contacts only give me 18.94 V. Is it safe to bypass the mosfet? Or have it replaced?
Hi nice video. I have the same 40v battery. When I place it on the charger it appears to be charging normally and when removed the battery lights indicate it has juice. However the battery still doesn’t work in my trimmer. Any thoughts? Would be nice if I could send you my battery for this mod.
Thank you for your video about fixing ryobi 40 volt battery. my understanding, it's look like those FET are most of the time THE problem because they do not want to open for charging or discharging. You show us how to charge under monitoring. So at the end it seam to me that it always a battery problem. if I am right, i guess it will be best to removed the board, buy new batteries and placed them in a case to made too packs of 20volts and add over them the board and put everything back in the original case. what do you think about that. excuse my english i am french form canada. so in the futur it will by easy to test the bad battery ans changed only this one
The FET's rarely fail, it is usually a faulty cell or other board component. I have removed the board and disassembled a dozen packs. The board is usually damaged from disassembly and even if you could find the faulty cell and just replace it, it would be almost impossible to do it without removing the board first. You would have to buy a separate 40V BMS to protect your pack. I am planning a similar build and will post once I have gotten all the parts. Thanks for watching
@@thecityviking Thank to the replying, so even being very carefule with the board, if we need another 40 volts bms to rebuild a new battery, I have seen another Guy on youtube, doing battery for e bike and he use new bms, he ordered from internet, As I remember, that Guy even as written a couple books related of doing battery. I have looking forward to see you new video. thank again to help us with dose ryobi battery that don't last much.
I'm an EE and tried to fix my 40v battery. Ryobi is getting smart and disables the battery pack after certain conditions so ppl like us cannot fix it by replacing the batteries. The microchip sends a signal to burn a small value resistor to kill the battery and disable the gate. The hp inkjet did exactly the same thing so ppl do not refill the ink cartridges. I saw someone rest the bms using rest pins. I didn't have a such a lock. You can short circuit the mosfet s and d legs and you don't need a resistor. However I think with all the fixes the battery still won't charge by Ryobi charger and you have to charge it using your homemade charger. If you're into fixing the battery pack, look for a small smt resistor which is open and is burnt . It must be close to a transitor, since no microchip has enough current to burn a resistor. If you find that resistor, please create a clip and let us know which resistor needs to be replaced. Good luck.
*I took my battery apart and I noticed it doesn't have the FETs at all . Have you seen this before. I got the battery for used for repair so im not sure about the history of it. Do some of the come with out Fets anybody ???*
All BMS have at least one FET, at least all the ones I have ever seen. The FET is like a switch. When it is fully charged, it switches off to stop overcharging. When discharging, it switches off again to stop over discharge. This is done to preserve the life of the cells and for safety. The BMS will also switch off the pack if the cells are very out of balance. I would first make sure all cells are close to each other, say 3.600V. If all the cells are within 100mV or .100V of each other, they should be OK. Thanks for watching and check out my other video on these batteries. ruclips.net/video/WKY1-JNijqo/видео.html P.s. a FET can come in different packages, so it may look different, but it always has 3 connections.
The problem seems to be with the circuit that turns on and off that FET. The mod I show just allows the FET's to be controlled together by the other part of the circuit. Instead of the two FET's being controlled separately, they both work together. You are bypassing some of the protection of the BMS, so do not charge it unattended.
@@thecityviking Agree but as you stressed, 1A charge should have no problem. I found a nice booster on eBay as now Jan 2021 Amazon still nil stock. Good video. Thanks.
I cannot find the resistor that you used everything I have ordered 15k ohm is too big to fit in the battery to put the top on do you have the number of the resistor you used
My ryobi mower battery dies before it fully discharges. An electrician told me that it's that the relay is causing it to overheat. He told me to take the relay out of the battery. I opened the battery but don't know where the relay is. Does anyone have any suggestions?
There is no relay in the battery pack. The battery uses FETs to turn off charging and discharging of the battery. I would check individual cell voltages and see if you have one set of cells that is low. While you can bypass the FETs, you will effectively be bypassing the safety features of the battery pack. Please only do this if you understand the risks involved.
The screw itself is not actually connected to the negative of the battery, but rather is just a spot where I connect the alligator clip and the side of the clip touches the negative pads. I hope this helps. :)
Unfortunately I don't have any single FET boards. If I come across any I may make a video on it. You could bypass the FET with a short across the source and drain, but you would have to monitor all cells to prevent overcharge or fire.
For people that's not knowledgeable about electronics and how they work and especially dealing with voltage should never open this up to fix. Only experience people that knows what they're doing should do this. For those people that are not experienced in this area the easiest solution is to call the number thats in a video I made on this same topic. Because these batteries are already under warranty and they will send you another one for free. Or you can pick it up at the store for free. Video is on my page.
They won't do that in Australia. You have to return the tool and battery with original packaging. I now have 3 dead batteries and I will be trying this mod.
I have not yet had a 40V Ryobi battery die so I've not taken one apart. However, it is my understanding that there is a reset on the circuit board and once you have partially recharged the dead battery, you need only activate the reset and the battery will work properly again. No modification needed. But... I will have to wait until one of my 40Volt batteries does die before I will be able to confirm this for myself.
There is also a transistor that fails that causes the battery to not charge. I can't remember where I saw that though. Check out my other video about these batteries ruclips.net/video/WKY1-JNijqo/видео.html
Unfortunately its difficult to buy just one resistor, but here is a link to a pack that should work. The resistor value is not critical, so pick the closest one. Good luck.
Great Video. Im saving this for future in case ba ryobi 36v gets into same problem. But i also have a question which hopefully you have solution. I have this other battery of same model that have all of its LED are on as if they are full but when used - there arent any juice. So i attempted to charge it with its charger - the charger says that battery is faulty. Any remedy for this case sir?
I have a couple batteries that show a charge like that but when I open and measure individual cell packs usually there is at least on set of cells that are dead(below 2.5 volts). I have tried charging the cells individually but they discharge quickly. I will harvest the rest of the cells for building a a new battery.
I have 2 batteries with the single FET. when I measure voltage on the contacts I get 20V. When I measure from the + contact to CL1- on the board I get 40V. Any ideas? I had another newer that was to low to charge, I charged it on a supply at work and got it from 16V to 35V, I shorted the reset contacts and got it up to 35V, took it home and now the charger is working on it. Any help would be great. Thanks
The FET is probably not on and so the voltage does not read correctly. This is normal operation. I explain it in my other video "Ryobi battery questions answered". Thanks for watching
Yes, the bleeding edge it is. But the customer is left bleeding. Profits before functionality and no alternative for early buyers except to shell out for new batteries a $300 a pop. Class action suit maybe here.
All the Ryobi stuff I have is from Kijiji or pawn stores or tossed out on the road. I picked up 2 batteries brand new in the package for $200. Thanks for watching
Hi good video. I also have a few batter with 1FET. My battery has 42v over the cells and 21v +, - the plug. Measures the voltage on Gaite at FET where it is 0v should be at least 10v. It must activate FET when you load the abbey and then get 10v. But can not figure out where the signal should come from. Has anyone had this problem.
Well, I can't go back in time, but I can give you my word that they did not charge on the Ryobi charger before the mod. I have a second video where I answer a bunch of questions about these batteries. ruclips.net/video/WKY1-JNijqo/видео.html Thanks for watching.
Not sure what you are looking for. I have everything in the description...I think. Could it be... amazon.com link for power supply I use: amzn.to/3hXIysX
@6:50 "Loupe" is pronounced the same as "loop". It's a word English stole from French. Many variations on the same premise will be called some description loupe. Like Jewlers Loupe, Dentists Loupe, etc.
I have 40 V Ryobi Battery showing full charge, When i check voltage across + and - Terminals it shows only 18-19 volts. voltage on the board -ve and +ve terminal is 41 volts . Voltage between T1 and +ve terminal is 41 volts. seems like battery is fully charged. It does not run my weed eater. can you suggest something.
Are you sure the problem is in the battery? Do you have a second battery to try in your weed whacker? Can you connect some other load up to + and - terminals? I use a 100w incandescent(old style filiment) bulb conneced to those terminals and it draws .5 maps and the bulb glows but not at full brightness.
@@thecityviking My weed eater is good have tried on a different battery and it works fine, this battery that i want to revive went into the sleep mode. I tried to charge it by pushing it into the charger a few times and it started to charge. After the full charge it wont turn my weed eater.Checked the voltage on +ve and -ve terminal it was at 19 volts. Checked the voltage between battery ground and +ve terminal it reads 41 volts. Checked the charge on the battery all the lights comes on. The charger shows its fully charged. I am lost
I have found a few batteries where the board looked the same, but they act differently. I suspect that there are different software running on the boards. Have you measured the 10 pairs of cells individually and are they around the same voltage? I am going to be making a new video about these batteries shortly.
I have the exact problem with my battery, 18 volts between the + and - terminals 40 volts between the + and main ground on the board. Today I ran a jumper wire from the main ground and + terminal to the trimmer and it ran for almost an hour. The battery discharged to 32 volts so I put it back together and charged it. No change still 18 volts between + and - , 40 volts between main ground and +.
*This video is pure gold. I was about to give up on those ryobi batteries. ryobi community seems to have ALOT OF ISSUES with those 40v batteries.*
Glad to hear it helped. I also have another video that answers some questions about these batteries.
ruclips.net/video/WKY1-JNijqo/видео.html
Thanks for watching, and please share.
That’s coz they be like crap
@@georgedavall9449 Lol . Yeah i ended up getting rid of mine because the issues became frequent.
Saw that other video you were talking about and it sketched me out as well. Thank you for this
You are welcome
This was great I fixed my expensive 40 volt battery. Thank you for the helpful video!
You are welcome. Thanks for watching.
Thanks! great video
Thanks for the super thanks!
Even though out of my skill level, this was a fantastic learning experience!!
Glad you enjoyed it.
Thanks 🙏🏼 A Million just fixed my battery pack following your video. It worked like charm. Saved me 199$ battery with simple hack.
Somehow, I missed this comment until now. I am glad you were successful, and thanks for watching.
Cracked up when you grabbed that hot lead.... been there many times LOL
:)
I was super nervous when he was fumbling around with the board exposed lol. Those capacitors don't play!
Thanks for uploading ....there is no way I could imagine doing that ....your a genius....wishing I had the skills you do ....great upload 👍
Thank you very much!
Hi, Very carefully followed your instructions. Cut the trace cleanly and completely. Soldered the 51k resistor on the two points indicated. But when I insert the battery into the charger, I still get the red/green flashing lights, and when pressing the button on the battery, all four green LEDs on the battery flash four times. Any recomendations? Thanks
Have you watched my other video Ryobi 40v battery questions answered? What is the voltage across the individual cells?
Excellent video. I tore mine apart and noticed the board looks different than yours. There's a large glob of solder closer to the negative terminal. I've tried boosting it enough to get recognized by the charger by charging it at 1amp 31v from power supply, but only get one blinking light and still won't get recognized by the charger.
I ordered a DC DC voltage booster and hoping that can do something since I can jump the voltage to 40 or 41v vs the 31 that my power supply tops out at.
I saw another comment where you mentioned to check the voltage of each individual cell and balance the cells. How do you do that when this back is assembled in a way where I can't get terminals to the parts of each cell pack that I need to?
The board measures the voltage of all the banks of cells, so you should have access on the board. You may have one of the newer boards that is very different, but all cells should be accessible from there.
Hi,
Newbie here and working on to fix my Ryobi 36v, 2.6A lawn mower battery. Since it was manufactured in 2015, I was thinking its time to replace all batteries (since it is not performing well) and I did. After changed, pretty much I am getting 40v at the pcb boards pins. But, when I measure across 2 main terminal point, T1 and T2, I am getting only 16.5v. Is this normal? With this condition, I was able to recharge and use it again but performance almost the same. Is the mosfet failing? Any ideas to fix my problem, please let me know. Thanks in advance.😊
I don't think the mosfet is failing. Those things either short out or stay open, which would cause no power or full power. I would ask where you got the batteries from. Laptop batteries won't work as these ryobi batteries are high current batteries. If they are new batteries, I would test them with a load to see if you were scammed as their are a lot of cell sellers that are not trustworthy. Good luck.
@@thecityviking The batteries might be the cause. I use cheap China batteries but with higher current, 5800mAh each. I assumed it should give me more hours, 11.6Ah 😂, will it?
Bit late question to ask this but idk,
My dad has a 40V 5 Ah 180Wh Ryobi battery (Model: OP4050) for a lawnmower, Which was like a entire set that he picked up somewhere on the side of the road, But when it went into sleeper mode we have done everything from going in and out with the charger before it goes back into sleeper mode,
To tring to use the reset terminals (I think that is what it is called). And he thinks its something to do with the "Mof" thingy (atleast what he thinks its called. Idk didnt watch the full video). Any suggestions or?
Check the voltages of each cell. They need to be above 3V each, and all cells should be about 0.100 or less of each other.
this was great thanks for a clear and concise video.
I am glad you enjoyed it and Thanks for watching.
GREAT video - thank you!! You said, "don't charge these without being attentive", does that mean the charger will/can overcharge using this modification? Any insight you can share about your warning would be appreciated!!
Nice Video. I like seeing videos like these :) .
I have a video that I have to upload about powering my ebike with 2 ryobi batteries.
Nice video - I have a later 40v battery so the circuit board looks a little different - at around 9.40 you implied that when you have done the mod you are disabling the charge controller BMS and there is a concern there - what exactly do you mean? Will this result in the charge system not switching off when the batteries are charged?? My battery got left out in the rain, no corrosion but is now only 15.5v and the four green lights. On charge it gets the usual oscillating red and green lights on the charger.
Yes, the mod does bypass the BMS charge circuit and you become the BMS for the battery. Only charge the battery while you are there to monitor it. I hope that clears things up for you. Thanks for watching.
Could add temperature fuses that add back the protection that the BMS would be giving
That would help for overheating, but the bms also makes sure the individual cells don't discharge too low or charge too high. Thanks for watching.
Thank you so much for this video but I do not know why we do not charge the battery with its Ryobi charger? Or is there a bad signal at T1?
The charger and the battery communicate on the T1 pin. If the battery tells the charger the battery is no good, there is not much you can do to get the Ryobi charger to charge that battery. I have been trying to get an older Ryobi charger to see if I can "hack" it.
@@thecityviking Thank you! I have got it...
My battery's LEDs are all blinking green when I press the button, and the battery won't charge. If I cut the trace connecting the pin and capacitor for the Fet, and then don't solder in a resistor, can I still charge the battery without any problems?
Blinking lights o. Your battery probably means you have an unbalanced pack. You need to check all the individual cell pairs and see if they are all at the same voltage. I would try and charge them equally and see if it charges on your charger first.
For the FET that will not turn on why not just solder a jumper between the Source and the Drain of the FET, this will have the same effect as the FET being turned on using the Gate, but without cutting any traces.
I agree that will work. The reason I decided to cut the trace and tie it to the gate of the other FET is to possibly get some protection. If the pack starts to overheat or overcharge I was hoping the intelligence in the pack may try and shut down the other FET to protect itself.
By modding either way you are defeating a safety mechanism that is why I never charge my modded packs unattended.
@@thecityviking That's a safety minded approach and is probably the better idea, but it is based on hope and not fact, but it is the better idea. And any item that is modded without having an accurate understanding of how the mod _WILL_ effect the circuit should always be personally monitored.
Great video, thanks.
With this MOD will the original charger work? or do we need a constant 40v?
or can I bypass T1 to charge gate to open it and use original charger? thanks
It depends on which charger you have. I think the older ones will, but the newer ones may not.
Thanks for watching.
The 2nd option at 10:54 you said, can’t work after the battery is charged with the cover on? If the voltage is above the (30 )threshold doesn’t that mean it will work fine, with the cover on unless the voltage dips below that threshold?
When I have a battery that won't take a charge, I always leave the screws loose that hold the cover on. That way I can easily open it for charging and also monitor individual cells to ensure even charging. The BMS in these batteries seem to lock out charging from the factory charger once they have detected a problem with the cells. The mod I show in this video with the resistor only works on older firmware.
Hello, I must say Great video! You really seem to know your 40v ryobi batteries.
Now for my question, I have built a robot from hoverboards and retrofitted a lead acid scooter to both use 40v ryobi batteries. My issue is when using 2 batteries in parallel one of the 2 batteries will be greedy and hog all of the load, thus making the motors over draw the battery and drain it to quickly while leaving the other battery at a full charge. Do you have any idea on how to make them share the load nicely? Sometimes I can get them to share if they are both fresh off the charger and I unplug the one that has the load and apply a load and press the charge indicator button then plug back in the original battery with the load still active. Kind of a convaluted process. I am hoping for a resistive solution. Thanks
I noticed the same problem when trying to power my bike in my other video. I just run on one until dead and then switch. I know this is not a solution, but there is no real easy way to get around this, at least not safely.
Thnaks this video, I have some trouble with it.
Can I soldering 10 AWG wire connected "CL1-" and "tab-"? it looks like same way to bypass FET?
That would definitely bypass the FET's, but that could be very dangerous. You would have nothing preventing the pack from over discharge, or over heating. I do not recommend that.
Hello City Viking I have same problem with a Ryobi 36volts 5.0 ah battery it blinkes when i slide in the battery in to the charger after few seconds stop's to blinke and there's no more any other issue than that it's all Dead at not charging not blinke please help me with this battery to fix
Have you opened the battery and checked the voltage of each pair of cells? All of the cells inside should have a voltage that is close to all the others. It could also be your charger. I will be posting another video soon about these batteries and how to check cell voltages. Stay tuned!
@@thecityviking I think you got it because I think I have forget it about that it's been like 6 months ago the charger it bloud a spark lights made this with like a shot because the charger goted spilled some water inside but i didn't think it was it was the charger because it is still working regularly with all the function
I have tired different approaches and cannot seem to get any of my old batteries to come back. I have 11 of them. I am wondering if I should make a battery pack out of them for something else.
I have 20 and plan on making a battery pack. I have some ideas but not sure what final voltage I want. If I make it for my trailer it will either be a 24v or 12v. I may make one for my new bike motor. A 1000W mid drive that runs on 54v
I have a battery that came and it never took charge. I tried the jump reset and it didn't work. I am wondering if this would work. When I try the jump reset method the light for the battery doesn't come on until I press the button and when I do that it stays on, thoughts?
I would charge up the battery and then try the reset method. Make sure you charge up the cells evenly though. I hope that works for you.
is there a formula or method you used to determine which resistor to use? i'm not clear on how you got there but it's a creative as heck bypass and the resistor idea is fantastic - a second question is - have you seen other batteries use two fets to work in the same way? i'm thinking this is some kind of standard practice - but then i'm not sure why manufacturers would sometimes use only one fet lol so many things to learn.
The gate resistance is not critical for slow switching. Many gate resistors are around 1k and higher resistance will still work but may slow down the switching on of the FET. Since this is just on or off not rapidly switching back and forth I picked a larger value.
The formula is something like this.
IGPEAK=(VG(on) - VG(off))/(RG+RG(int)).
Keep in mind though, that if you go too small, you could kill the FET, or the drive circuit.
Often, most BMS circuits I have seen have many FETs, but it is to increase the current they can switch. If you need to switch 100A, you would have to use many FETs to accomplish this.
I have never seen a BMS that has seperate charge and discharge FETs like these Ryobi boards. The earlier Ryobi 40V batteries only had one FET, and maybe they found an issue that they felt warranted this.
Most BMS circuits have FETs in parallel to increase their current switching, while these Ryobi BMS circuits have them in series. I think they may have done this as an extra safety. FETs can fail as a short or as an open, so to have a runaway short circuit you would have to have 2 FETs fail the same way.
So if the BMS shuts off the discharge FET, then the charge FET is also turned off (since the gates are paralleled). If that happens, how do you turn them back on?
They are not parallel they are series
@@thecityviking weren’t you tying the gate of the charge FET to the gate of the discharge FET through a 51K resistor? Given the high gate impedance, it seems this is driving the two gates with the same signal.
@@thecityviking Thanks. So if the BMS turns both gates to the two FETs off, is there a way to turn them back on to allow charging?
Sorry, I read your original post incorrectly. You are correct, the gates are paralleled. The charger does not charge the battery on the newer battery packs because there is communication between the charger and the battery pack. If the pack tells the charger that it is defective, the charger does not provide the charge voltage. I think possibly we need to modify the charger and the battery?
@@thecityviking perhaps so. Unfortunately, I’m not familiar with the details of the circuitry in the charger or the battery. So I have no intelligent feedback on the best way to approach it. You’re probably much further along on ideas for the best way to do that.
To Save not opening case? Pluggable pin hole above ground. To rase voltage above charge requirements, with your charger? May help?
Accessed grd & voltage points on 18v with accessing in plastic case. no Chang in board change.
Is this a good idea?
I think that's a great idea.
got super excited finding your video because im having the same issue w my 6ah 40v op40602 battery crack the case open and competely different board manfacturing date on mine is 2019 4 13 back to the drawing board lol but A+ video man keep up the good work
I have a couple newer batteries, but they both work fine so far. I was thinking of doing another video just talking about these new batteries and how to check them and possible alternative charging.
Hello there . I’m very curious in how I can reduce power curro from 120v to 40v dc my thing is , I want to install direct power to a 40v sunjoe pressure washer to stop using the battery and have direct controlled power to the machine
You would need to purchase a 40 volt high current power supply.
Hallo.
I have 20 V at the + and - terminals. But when i check terminals + and T1 then it is 40V.
When I connect electric motor for testing it does not start.
What could be the problem??
Sounds like one of 2 possible problems. 1. The FET is damaged and not working and turning on. 2. The signal that is supposed to turn on the FET is damaged or not coming on for some reason. If it doesn't work in a tool, you could try jumpering the FET to bypass it.
I've got an older version of this 40V with the single fett (spelling?). I have 38V from Negative rail to postive terminal. But only 17v from negative terminal to positive terminal. So something in that fett is holding me back?
Sounds like the FET may not be turning on or is damaged.
Thank you VERY MUCH for this fix video....but....what size resistor do I need to order? 1/4 watt, 1/2 watt, 3 watt? (51K ohm of course) Sorry for being an electronics newbie. Your resistor looks a bit small, so I would guess 1/4 watt?
Good question. The resistor I used is 1/4 watt. There is virtually no current through this resistor as it just passes the 10 volts from the one spot to the other to turn on the FET. Make sure you do have 10V at the other side. Good luck.
@@thecityviking Thanks so much for the nearly instant reply! YOU rock!
You are welcome
i have a older 2 fet batterty mine looks different and don't see were the trace is so i need to cut the gate on neg to tie in is what im understanding
Basically you are cutting the trace for the gate of the FET and then tying it high to keep it turned on. Remember though that you are bypassing the BMS, and now you have to monitor cells to ensure safe charge/discharge.
Thanks for watching.
Hi City Viking. Thanks for the video. Could you please clarify. Is it a faulty FET causing this problem and could I just replace the FET or is there some other issue causing the FET to remain open. One of my batteries gets the blinking light of death on the Ryobi Charger. I've pulled the battery apart and charged it manually through the postive connector and the screw terminal as you showed, but the battery will not charge on the Ryobi charger after manually getting the battery up to full charge. Therefore the problem is not because the battery is too low in voltage. I could cut the trace and apply the resistor as per your video but I could also replace the FET. Is there a way to test the FET while it is still connected to the board to determine if the FET is the problem? Cheers Marty.
It is possible that tour FET is faulty but in my experience it is unlikely. Basically what happens is the intelligence on board determines that the pack is defective and it doesn't allow charging. I will be making another video shortly that will describe how the pack works and why it fails and how to properly check each cell set.
@@thecityviking Thanks for the info. I will do your mod and see how it goes. I'll let you know. Cheers Marty.
i have a stack of the 1,5A with one mosfet, do you know how to fix them? they show 1 green when i pust the testbuttom, but in the charger it says fully charged. When i put it in a tool it will not run. Any suggestions?
You need to check voltage of the pack and the individual cells. It could be that one of the banks of cells is low, or the whole pack is too low to charge properly. thanks for watching
@@thecityviking Thanks for answer. It has the right voltage when i measure inside (around 37v) but between the + and - terminal its only half the voltage. i can take the - inside from circuit board and it will run a motor.
I wouldn't mess with lithium ion batteries the discharge safety mechanism is there for a reason they can be ticking bombs if not put back together the proper way for the BMS to function
I agree. Never disassemble electronics without understanding the risks.
subscribed
great video, does this mean that you can never use the Ryobi charger again?
I can not give a definitive answer to that. The Ryobi charger communicates with the battery, and that is what determines weather or not the Ryobi charger will work or not. I have had some luck with the older battery packs working with the Ryobi charger, but no luck with the newer battery packs. Thanks for watching.
Very good video and informational. Will that work with Mikita battery I have a lot of them? Thanks
You may be able to charge up individual cells on the Mikita to get a little more life from them. Unfortunately I don't have any to play with to know for sure.
I would solder the resistor in line with a momentary switch so I only jump the gate when needed. Not sure why you need to cut the trace?
I like the switch idea!
I cut the trace so that high signal from the resistor mod doesn't feed back into the low signal coming from the rest of the circuit. It could cause more damage to the circuit.
i was trying to solve same issue with bunch of milwaukee M18 batteries won’t charge or flashing light
what i need help is to figure out to do the jump cuz there is only one mosfet
I would check to see if the batteries are balanced first(all within .01of each other)
@@thecityviking i brought them back and balamce
what's about the newer ryobi 40V battery OP40401 that won't charge?
I currently do not have any defective newer style batteries, but I am thinking of making a video on the newer batteries.
Link to your charge board? I can't seem to find any that have a red/green indicator light. Also, is yours able to step up the voltage from something like 12v? Of are you having to power that board with a separate power supply of at least 41V?
I power mine with a 12 power supply from a computer so yes it is a boost converter. I checked my purchase and its not available any more, but I will see about finding a similar link for you.
www.droking.com/150W-Power-Supply-Module-DC-10-32V-to-10-46V-16A-Adjustable-Boost-Converter-DC-12V-24V-Voltage-Regulator-Adapter-Charger-Driver
@@thecityviking It appears that link is in stock. Though the Amazon affiliate links were out of stock. So I'll try ordering directly from droking.com.
Dude... this vid is amazing.
Thank you. :)
What is this you are using? And where did it come from?
I am not sure what you are talking about. Can you explain?
Hello,
I have a 40v pack from 2013 with samsung cell in it and measures 42.2v between CL1- & BAT+ terminals. Also I measured CL1- & CL5+ and got 20.5v also CL6 - & CL10+ is giving 21.7v. But actual terminal + & - from the pack is only giving me 20.5v. Btw, Pack charges good and been sitting for a week. Is there anything I can do to revive it? Final note, the tool runs for about a minute or two and dies with battery light still on with 3 green dots and 20v.
Thank you
I had a pack like that and it turned out to be a couple bad cells. It was on a pack that had a single FET and when fully charged would run lawn mower for about 2 mins then it would cycle off and on. I bypassed the FET and found that the pack would get hot in one set of cells. That set of cells would be much lower then the rest of the pack. You can not recover the pack but I did salvage individual cells to power other things.
Thank you for the response. That was my initial thought too. And yes, it’s the one with single FET. I guess it’s time for salvage. Btw, I found out that it’s not a AA size. What projects are these cells useful for if you don’t mind me asking?
Thank you
@@bbg5939 These cells are lithium Ion and are 3.7V nominal, that do charge to 4.1-4.2v with a proper charger and you can use them in laser pointers, vapes and special torches, most people use them for those things but they can also be used as E-bike or E-skateboard packs, there are other uses like batteries for your solar power storage, but you need a bit more expertise to do that and a ton more batteries. BTW if you let them discharge too low it reduces the cell life, with these cells you're best not to let them get below 2.5V each but charge them when they are somewhere between 2.5 and 3.5V up to say tops 4V (as overcharging at 4.2V+ also reduces their life!) Overcharging and over-discharging Lithium cells is dangerous and can make them explode and set fire to stuff like houses and garages so beware, this is why they have a battery management system to limit the discharge.
Great video on charging.. my bat has just stopped being charged. I may actually get a non Ryobi replacement from eBay and also try to get your screw mod working. What bench power supply do you use for the DC to DC boost converted? I will probably try to use the screw mod 1st and carefully monitor the battery voltage as you say this bypasses the overcharge protection.
I use an old laptop power supply to convert 120V ac to 18V dc. Then I add the dc-dc boost converter to get 18V up to 40V. Hope that helps.
That's the board mine as but mine shows full charge but won't work in the blower or string trimmer. My other battery works fine.
All the lights sometimes light when the battery is very depleted. Check the charger on the battery to know if it is truly fully charged.
@@thecityviking I have 2 chargers, both see the battery as fully charged. Occasionally it shows error when first plugged in but I remove it and slide it back in it shows full. Definitely strange. Also when checking the charge by the button on the end it shows full.
I wish I saw this a year ago. I bet my battery packs are really dead now. Does the board stay dead? Can I replace the cells in this pack?
I have bought completely dead ryobi batteries and was able to bring them up to full voltage with no problem. I show how in one of my videos.
Good luck with your batteries.
Is there a way to do this same fix on the older model with the single fet? Or any other fix? Thanks
Check out my new video that shows other options for the single FET.
Why not just bridge the source drain of the fet. When your done you would only have to cut the jumper to undu. Seems a lot easier
In the video, I talk about this and explain why I don't do this. I tie the gate to the gate of the other FET so the BMS can still shut off the power. Thanks for watching.
I have a OP40301 (40v 3.0Ah) and OP40261 (40v 2.6Ah) which have both stopped charging. Do you have a fix vid for these??
Not at the moment. I do not have any of those batteries. If I get some I will see what we can do. :)
@@thecityviking I can send you some to play with.
I am looking at making another video about a Rev Q board that is in the newer Ryobi batteries. Perhaps that is what you have in your batteries. Coming soon!
Thanks very much Great video and well explained.
Well thank you for the compliment, and please share.
hi, I really enjoy your suggestion , but after I opened my batterie, it has a different layout I wish I could send you a picture to see if you have any suggestions how to solve it .
I am looking at making another video about a Rev Q board that is in the newer Ryobi batteries. Perhaps that is what you have in your batteries. Coming soon
@@thecityviking I also have a Rev Q battery and it is definitely a little different.
I have a 6AH Ryobi 40V (OP40602) took apart. Voltage on cells appear to have 0V. Any suggestions to revive it, thanks
It may be possible but I would not recommend. Look at videos showing how to revive , reset current interup device in 18650.
Cells may be just drained to 0V. I would try charging individual cells slowly. Start with 1V and 500ma. If it charges to 1V, then try 2. Once over 3V you can try charging quicker.
If you could provide a link to where to an example of the charging device that you are using it could be very helpful to people.
Also, you seem to understand this circuitry pretty well. I have a couple of packs whereby I have verified each cell is charged to full voltage, yet I only get half of the voltage at the main terminals. From the main pos and neg charging terminals the pack reads 20.5v and from the main negative terminal to each individual cell I get about 2v even though each cell is charged to 4v. Any thoughts on what is causing the BMS to restrict the pack to half the voltage at the main charging terminals?
From Amazon
Yeeco Boost Converter Module DC-DC Step Up Converter Board 8-32V to 9-46V 8A 150W Voltage Regulator Booster Module Adjustable Voltage Step Up Power Supply Module
I use a laptop power supply to provide input power.
@@thecityviking Thank you. Any thoughts on the 2nd half of my comment? Also, any idea if we can use the "rst" location on the board to reset the chip? The available pins are: CLK, DAT, GND, 3.3v, RST. I wonder if we would briefly shunt the 3.3v to RST? Now that I have every cell at full charge I am wondering if it is possible to manually reset the chip using these locations on the board?
Sorry I didn't see the second part. I believe I know exactly what you're talking about. The voltage is not being restricted the pack shuts off the FET when the pack is not being used if you hook a small load up to the main terminals and then measure it you should get the proper voltage but it only lasts for about one minute and then shuts off. I will make another video explaining this for others.
can you make a fix it video on the OP40602 battery and the OP40301 battery packs please?!
If I get some ill take a look to see what I can do
Is there a way to basically do the same procedure with a single FET battery?
Not sure. I'll see if I have one and try and figure it out
Awaiting the same!
Thanks City Viking, great video tutorial, my battery is dead as we forgot to leave it charging last winter, but it's the model with one FET, what would you suggest to do in this case, just desolder the FET completely, force charging it to some charge, then replace the FET and charge normally?
I would try charging it like I describe in the video using alligator clips. One on the positive and one under the screw(negative)
Great video. Can you please give the name or the link of little charging device. Thanks
amazon.com link for power supply I use: amzn.to/3hXIysX
The link was in the description. It works with an input between 10-32V and has adjustments for voltage and current on the output. Output has to be higher than the input. I use a 12V power supply from and old Computer but you could use a laptop power supply as well for the input. I Don't set the current higher than one amp for safety.
Looks like they are currently out of stock but should get more. It's usually under $20.
Good luck!
11:12 Say I want to "save" what the charger thinks is a dead pack. This seems to be the solution!
Just make sure you are charging all the cells evenly as you do this. You don't want any cells over 4.2V!
Can you do one for the 18v batteries? I know they similar but don't want to screw it up
I unfortunately don't have any of those batteries, but if I find some at a garage sale or somewhere cheap enough, I will.
Thanks for watching
Hi CityViking! I have ryobi lithium pack rated at 36v 4Ah, (model BPL3640). I was told it was shot, but after placing it in a charger it charged to full - indicator shows all 4 lights - it took about 2hours with 1.7A charger. But, when i place it in a tool - it wont start - so i guess i have similar problem as shown in Your video but with discharging. I pop the battery pack open and check all cells - they show good voltage around 4.2V. And when I check battery pack voltages it gives me around 19V between + and -, 40V between + and T1 terminal, and 0V between + and T2. I have got a good pack and when i measure it, it shows 36V between + and - , 36v between + and t1, 36v between + and t2. Can You give some advice where to look? Should i check again each cell or start looking whats wrong on pcb? Where to start? Does this "hack" also work for discharge issues?
you could try bypassing the other FET to see if your tool starts to work.
Does it need to be specific with the 51K ohm resistor? or can you go the next number up or down? Also instead of the Mod would it be possible to replace the FET with a new one to fix the charging issue? I'm just asking since the Mod does override the Over Charge protection of the BMS. Thanks in advance.
Resistor is not critical. You could be thousands of ohms off. The FET usually is not broken, the circuit just won't turn it on..this mod forces it on.
Hi! New subscriber here. Have you tried to fix the older 40V with the BMS having only 1 MOSFET?
I have had a couple of those single mosfet boards. While you could completely bypass the mosfet, I would not recommend it. If you get all the cells to approximately 3.5V and are fairly balanced, you may be able to charge it, but I have no other advice at this time. Thanks for watching, and check out my other video if you haven't seen it yet.
ruclips.net/video/WKY1-JNijqo/видео.html
@@thecityviking thanks for replying. When I tested the voltage across the battery (not from the contacts) it gives me a 39.25 V but the contacts only give me 18.94 V. Is it safe to bypass the mosfet? Or have it replaced?
Hi nice video. I have the same 40v battery. When I place it on the charger it appears to be charging normally and when removed the battery lights indicate it has juice. However the battery still doesn’t work in my trimmer. Any thoughts? Would be nice if I could send you my battery for this mod.
This mod may not fix your battery but it could. I'm working on another video to show some of the problems with this battery
@@thecityviking link to the next video?
The link to Amazon for the charger is unavailable is there another charger you recommend?
The second link is valid. I don't think it has an led on it though.
Thank you for your video about fixing ryobi 40 volt battery. my understanding, it's look like those FET are most of the time THE problem because they do not want to open for charging or discharging. You show us how to charge under monitoring. So at the end it seam to me that it always a battery problem. if I am right, i guess it will be best to removed the board, buy new batteries and placed them in a case to made too packs of 20volts and add over them the board and put everything back in the original case. what do you think about that. excuse my english i am french form canada. so in the futur it will by easy to test the bad battery ans changed only this one
The FET's rarely fail, it is usually a faulty cell or other board component. I have removed the board and disassembled a dozen packs. The board is usually damaged from disassembly and even if you could find the faulty cell and just replace it, it would be almost impossible to do it without removing the board first. You would have to buy a separate 40V BMS to protect your pack. I am planning a similar build and will post once I have gotten all the parts. Thanks for watching
@@thecityviking Thank to the replying, so even being very carefule with the board, if we need another 40 volts bms to rebuild a new battery, I have seen another Guy on youtube, doing battery for e bike and he use new bms, he ordered from internet, As I remember, that Guy even as written a couple books related of doing battery. I have looking forward to see you new video. thank again to help us with dose ryobi battery that don't last much.
Would a battery tender work?
It would have to be a 40volt tender. I don’t even know if those are available. ✌️
I'm an EE and tried to fix my 40v battery. Ryobi is getting smart and disables the battery pack after certain conditions so ppl like us cannot fix it by replacing the batteries. The microchip sends a signal to burn a small value resistor to kill the battery and disable the gate. The hp inkjet did exactly the same thing so ppl do not refill the ink cartridges.
I saw someone rest the bms using rest pins. I didn't have a such a lock. You can short circuit the mosfet s and d legs and you don't need a resistor. However I think with all the fixes the battery still won't charge by Ryobi charger and you have to charge it using your homemade charger.
If you're into fixing the battery pack, look for a small smt resistor which is open and is burnt . It must be close to a transitor, since no microchip has enough current to burn a resistor. If you find that resistor, please create a clip and let us know which resistor needs to be replaced. Good luck.
Thanks for the video. it was very helpful
You are welcome. Thanks for watching. :)
*I took my battery apart and I noticed it doesn't have the FETs at all . Have you seen this before. I got the battery for used for repair so im not sure about the history of it. Do some of the come with out Fets anybody ???*
*I found a video of someone with the same type of battery having the same issue ....* ruclips.net/video/T6xMwPbcvn0/видео.html
All BMS have at least one FET, at least all the ones I have ever seen. The FET is like a switch. When it is fully charged, it switches off to stop overcharging. When discharging, it switches off again to stop over discharge. This is done to preserve the life of the cells and for safety. The BMS will also switch off the pack if the cells are very out of balance. I would first make sure all cells are close to each other, say 3.600V. If all the cells are within 100mV or .100V of each other, they should be OK. Thanks for watching and check out my other video on these batteries.
ruclips.net/video/WKY1-JNijqo/видео.html
P.s. a FET can come in different packages, so it may look different, but it always has 3 connections.
Great video. I was under the impression that once you charge up the pack, the gate would work properly again. Bad assumption?
The problem seems to be with the circuit that turns on and off that FET. The mod I show just allows the FET's to be controlled together by the other part of the circuit. Instead of the two FET's being controlled separately, they both work together. You are bypassing some of the protection of the BMS, so do not charge it unattended.
@@thecityviking tyvm
@@thecityviking Agree but as you stressed, 1A charge should have no problem. I found a nice booster on eBay as now Jan 2021 Amazon still nil stock. Good video. Thanks.
Thanks for watching!
I put 2 wires with alligator clips to the outer 2 terminals to a fully charged battery for 4 days now it's charging
Wow 4 days!
I cannot find the resistor that you used everything I have ordered 15k ohm is too big to fit in the battery to put the top on do you have the number of the resistor you used
amzn.to/3fL2ct0
Link for resistors that should work.
My ryobi mower battery dies before it fully discharges. An electrician told me that it's that the relay is causing it to overheat. He told me to take the relay out of the battery. I opened the battery but don't know where the relay is. Does anyone have any suggestions?
There is no relay in the battery pack. The battery uses FETs to turn off charging and discharging of the battery. I would check individual cell voltages and see if you have one set of cells that is low. While you can bypass the FETs, you will effectively be bypassing the safety features of the battery pack. Please only do this if you understand the risks involved.
@@thecityviking Thank you for responding. I don't know enough about the battery, so will give up on it and most likely buy a gas push mower.
You are welcome. Sorry to hear i wasn't able to help you.
So when I attach the negative to the screw my charge stops charging.
The screw itself is not actually connected to the negative of the battery, but rather is just a spot where I connect the alligator clip and the side of the clip touches the negative pads. I hope this helps. :)
@@thecityviking Thank you that makes since.
So how many watt hours of capacity does the hacked battery now have?
This mod will not increase your battery at all, it just allows it to be charged. Manually balancing the cells may help increase battery life a bit.
CAN YOU SHOW VIDEO FOR SINGLE FET
Unfortunately I don't have any single FET boards. If I come across any I may make a video on it. You could bypass the FET with a short across the source and drain, but you would have to monitor all cells to prevent overcharge or fire.
For people that's not knowledgeable about electronics and how they work and especially dealing with voltage should never open this up to fix. Only experience people that knows what they're doing should do this. For those people that are not experienced in this area the easiest solution is to call the number thats in a video I made on this same topic. Because these batteries are already under warranty and they will send you another one for free. Or you can pick it up at the store for free. Video is on my page.
They won't do that in Australia. You have to return the tool and battery with original packaging. I now have 3 dead batteries and I will be trying this mod.
Why not replace the FET
Thanks for asking. Usually the FET's are not the problem. I have yet to find one with a bad FET.
I have not yet had a 40V Ryobi battery die so I've not taken one apart. However, it is my understanding that there is a reset on the circuit board and once you have partially recharged the dead battery, you need only activate the reset and the battery will work properly again. No modification needed. But... I will have to wait until one of my 40Volt batteries does die before I will be able to confirm this for myself.
Reset works if no lights will illuminate on battery…older packs do not have a reset button.
There is also a transistor that fails that causes the battery to not charge. I can't remember where I saw that though.
Check out my other video about these batteries
ruclips.net/video/WKY1-JNijqo/видео.html
How many batteries are in series? Thanks.
10 batteries in series 2 parallel. 20 batteries total.
So its a 10s2p pack.
@@thecityviking batteries meaning cells?
Yes sorry for the confusion. 10 cells in series and each cell has a parallel as well.
Nice job, did you have the schematic for the battery?
I have several of these batteries and worked on figuring out some stuff, but I did find a schematic online that someone made that helped.
do you have a link for the resistor? Thanks
Unfortunately its difficult to buy just one resistor, but here is a link to a pack that should work. The resistor value is not critical, so pick the closest one. Good luck.
@@thecityviking Thanks, it would be great if you ever have a chance to make a video for Ryobi 40V 4ah. That seems most people have problem with.
What boost converter is that?
Link is in the description and here.
amzn.to/3xWVVkJ
Thanks for watching.
@@thecityviking link isn't in the description. It is only the resistor and power supply and similar power supply.
@@thecityviking I guess you just labeled it wrong, I see now. Thx
can this be done to the 40301 ryobi
I think this only works with the older packs, but you could try it.
Great Video. Im saving this for future in case ba ryobi 36v gets into same problem. But i also have a question which hopefully you have solution. I have this other battery of same model that have all of its LED are on as if they are full but when used - there arent any juice. So i attempted to charge it with its charger - the charger says that battery is faulty. Any remedy for this case sir?
I have a couple batteries that show a charge like that but when I open and measure individual cell packs usually there is at least on set of cells that are dead(below 2.5 volts). I have tried charging the cells individually but they discharge quickly. I will harvest the rest of the cells for building a a new battery.
Will this procedure work on a op40301 battery
I am not sure. Sorry.
Nice video with detailed instructions but I have a brand new battery and charger that is not charging I wonder why?
if its brand new i would take it back. Does the battery have any charge? maybe check out my other video where I give more details
I have 2 batteries with the single FET. when I measure voltage on the contacts I get 20V. When I measure from the + contact to CL1- on the board I get 40V. Any ideas? I had another newer that was to low to charge, I charged it on a supply at work and got it from 16V to 35V, I shorted the reset contacts and got it up to 35V, took it home and now the charger is working on it. Any help would be great. Thanks
The FET is probably not on and so the voltage does not read correctly. This is normal operation. I explain it in my other video "Ryobi battery questions answered". Thanks for watching
continuity beeper on a multimeter is more reliable than visual assessment via loupe
I don't like to use continuity or ohms on live circuit boards. The risk of damage to the meter is too great for me. Thanks for watching.
@@thecityviking hmm.. maybe an LED + resistor?
I like that idea!
thank you it works perfectly
Yes, the bleeding edge it is. But the customer is left bleeding. Profits before functionality and no alternative for early buyers except to shell out for new batteries a $300 a pop. Class action suit maybe here.
All the Ryobi stuff I have is from Kijiji or pawn stores or tossed out on the road. I picked up 2 batteries brand new in the package for $200.
Thanks for watching
Hi good video. I also have a few batter with 1FET. My battery has 42v over the cells and 21v +, - the plug. Measures the voltage on Gaite at FET where it is 0v should be at least 10v. It must activate FET when you load the abbey and then get 10v. But can not figure out where the signal should come from. Has anyone had this problem.
It could be a bad FET, but as I explained in my other video, you do need to load the battery before checking the voltage at the + and - terminals.
Wish you had put in on a Ryobi charger for us to see
Well, I can't go back in time, but I can give you my word that they did not charge on the Ryobi charger before the mod. I have a second video where I answer a bunch of questions about these batteries.
ruclips.net/video/WKY1-JNijqo/видео.html
Thanks for watching.
where can i buy that ? name of it ?
Not sure what you are looking for. I have everything in the description...I think.
Could it be...
amazon.com link for power supply I use: amzn.to/3hXIysX
@@thecityviking ty sir
You are welcome
@6:50 "Loupe" is pronounced the same as "loop". It's a word English stole from French. Many variations on the same premise will be called some description loupe. Like Jewlers Loupe, Dentists Loupe, etc.
I know what you mean, but i swear I had a box that said Mr. Loopy on it.
I have 40 V Ryobi Battery showing full charge, When i check voltage across + and - Terminals it shows only 18-19 volts. voltage on the board -ve and +ve terminal is 41 volts . Voltage
between T1 and +ve terminal is 41 volts. seems like battery is fully charged. It does not run my weed eater. can you suggest something.
Are you sure the problem is in the battery? Do you have a second battery to try in your weed whacker? Can you connect some other load up to + and - terminals? I use a 100w incandescent(old style filiment) bulb conneced to those terminals and it draws .5 maps and the bulb glows but not at full brightness.
@@thecityviking My weed eater is good have tried on a different battery and it works fine, this battery that i want to revive went into the sleep mode. I tried to charge it by pushing it into the charger a few times and it started to charge. After the full charge it wont turn my weed eater.Checked the voltage on +ve and -ve terminal it was at 19 volts. Checked the voltage between battery ground and +ve terminal it reads 41 volts. Checked the charge on the battery all the lights comes on. The charger shows its fully charged. I am lost
I have found a few batteries where the board looked the same, but they act differently. I suspect that there are different software running on the boards. Have you measured the 10 pairs of cells individually and are they around the same voltage? I am going to be making a new video about these batteries shortly.
I have the exact problem with my battery, 18 volts between the + and - terminals 40 volts between the + and main ground on the board. Today I ran a jumper wire from the main ground and + terminal to the trimmer and it ran for almost an hour. The battery discharged to 32 volts so I put it back together and charged it. No change still 18 volts between + and - , 40 volts between main ground and +.
@@eddiedavis346 can you post the picture