Spoiler Saver Please remember that this is just for entertainment, what you will see in this video IS DANGEROUS!!!! Please do not copy anything that you see! I hope you enjoy it.
Already salvaged a few 18650 from a power tool battery, just one out of 10 was bad, useful cells to have hanging around I am powering my bike lights off them :), also I agree if you don't know what you are doing don't play with them, and definitely don't solder them.
Pro tip: take off your wedding ring when working on energized circuitry - or get a silicone ring. You could easily lose that finger if the battery welded itself to the ring. I still have a large scar from a metal watch-band that exploded when working on a car near the starter (the battery lead is always hot). I cringed every time you touched the sides of the battery with your ring on. Stay safe, I love the content, cheers!
Nearly mentioned the same thing in my comment Thomas...couple of years ago I managed to short a laptop cell on my ring and suffered with severe burns for weeks - super heating to say the least!
Great video! The circuit board is for balancing the cells, if you charge a few cells, the voltage will drop because it's being redistributed over all cells. Either connect the battery to a full other battery(with enough discharge) or charge each cell separate bypassing the board. Smart chargers will most likely detect the battery once it's about 15Volts
The mosfet besides the cap is probably blown. You can replace it with a mosfet from taken a motherboard. Measure in diode mode between source and drain, you should get 0.4 to 0.7 V.
Yeah my thoughts aswell. I would've checked the pads where the cap was, see if there is still a short with the cap removed. That mosfet looks like it took some heat and might have shorted.
I have worked with a lot of failed 18/36v batteries. I normally use a current limited supply across the whole battery set to the equivalent of 2.5v per cell and the current limit at 50ma per cell (150ma for 3 in parallel). Usually find most of the cells quickly (mins not hrs) rise to 2.5v if they haven't leaked and started rusting out. I find the bms is often the problem or is deliberately blocking re-use due to past excessive discharge. I end up discarding typically one bank per battery at most.
One trick to make the solder stick to the battery ends is to scratch it before soldering. So the solder has a mechanical connection with the battery. I repaired a vacuum like that and is going really strong. This will also make it easier to solder, you don't need to apply so much heat because the solder will flow to the scratches and grab into.
Protip when using continuity in-circuit: Always check both ways. Your meter uses voltage to check for continuity. However, the circuit may have voltages across two points that will provide a false reading. I learned this fairly quickly when doing car fuses. All fuses read perfectly, including blown ones, until out of circuit.
The safety issue with charging cells that have gone that flat is simple. They need reforming. You can do that by charging them @50mA per cell up to a voltage of 2.6 and keep them there awhile. That should recondition the cells adequately enough. The board and it's components may be another story entirely. If it has a fault lockout like other commenters have mentioned it could be completely rooted. The real acid test for the cells is to charge them and see if they keep it without self discharge over a reasonable amount of time.
I really enjoy your warts and all videos on repair strategies. It's always entertaining. I really enjoy the dépistage and admire how you refuse to quit
If cells drop below 2.7v the bms ic will destroy circuit for protection. I guess that ic is BQ and they will destroy the fuse near cells to protect them and some newer BQ types will lock themselves. In this case you can charge them from output so it’s look like that just ic is locked. You can try unlocking it by shorting data and clock to ground. If that doesn’t help, you will need to reprogram it. But, if you want to program it, be aware that in mostly cases, manufacturers protect them with the password.
Interesting. I was speculating the chip next to the replaced cap was effectively a system management controller that had gone brain dead. I assume it talks to the charger to relay system health (of the battery) and it was bad
On these batteries unless its something serious the IC bricks itself after 3 failed charge attempts. Good luck for anyone trying to hack these and unlock them. Tons of talented people have tried but Milwaukee has put lots of money into making them unfixable. However what you can do is get a new grey market board if you've charged the cells. This bricking behavior is why if it flashes red and green due to low charge it's important not to attempt again but to manually charge it back up. All of this is pretty readily available info.
I hate to chime in so late my friend, but I couldn't help notice the fuse was possibly the cause of the scorching. A damaged trace was loose and all the solder appeared to have vapourized.Thrown off by the continuity test you did as I have been many times. Funny that the fuse didn't blow from whatever the cause. Not that the resoldering of that fuse would solve the problem of course, but I bet the board would come to life for a better prognosis. These HD12 are very expensive. I have one on my bench that reads 17V all groups of 3 are in at 3.36V and yet the first LED blinks 8 times. I have not been able to find any damage to the board. Going to have a much closer look at the PCB and all. Here in Canada these cost $379 CAD
Don't know if this has already been mentioned but Doctor Lefthandthread replaced a Milwaukee battery CB with a knock off one to revive the unit in one of his videos, so they must be available. Love the videos Vince, keep 'em coming.
Hi there my name's TheCod3r from your mate TheCod3r dcom and in this comment today is another comment telling you to keep up the great work! Looking forward to this one
I know its over a year later and you may not care, but the Cap value on my board is 10uf. It is suprising that it's that large so I checked on the 12ah and double checked on the 8ah board. They are both showing 10uf. I have been working on one of these 12ah for a while now off and on. The boards on these HO packs are strange. Both the 12ah and the 8ah, once I removed the power from them to do a reset now they will not power on. Both boards did just like yours. No power. This maybe a HO pack issue? Just throwing it out there as I try to edit my video while troubleshooting mine. I hope collectively we can figure out much more about them. I do know the cells in these has issues with the 1st gen and Samsung now has the V3 of this cell out now. Take care!
Unfortunately you cannot measure the resistance of a power source like a battery with your ohm meter. As it uses voltage to determine the resistance, it will read wrong if there is voltage.
I just bought myself a nice new set of Makita LXT tools (SDS, Combi Drill, Screw Gun, Angle Grinder and Circular Saw) and I was gobsmacked. £120 for a battery and charger and they don't even come with the tools. Really is unbelievable how much they can charge for a few basic 18650s
Defiantly worth getting a battery welder, even just a small portable one as they are so much easier to use with these cells. Have you thought of just getting another 3P 5S BMS to manage the charging? It wont do all the LED's but may let you charge from the Milwaulkee charger
The black burnt thing you IPAed off was the bug- a worm or slug. Cant check resistance on a battery as it is a power source and will screw up the resistance measurement. The sets of parallel batteries ALTERNATE polarity - think batteries end to end like in a flashlight except in this case back and forth. Recharging fully discharged lithium cells is NOT unsafe (I've recharged HUNDREDS of fully discharged cells and lipos), the full discharge just reduces battery capacity sometimes all the way down to NO capacity.. The dangerous thing you did was to REVERSE POLARITY most of the other parallel sets. The way I rescue packs is to use a TP4056 and charge each parallel bank slowly. Your cells are probably around 4Ah and when in parallel (by threes) will be 4Ah x 3 or 12Ah and charging lithium batteries is safe at up to 1C so 12Amps per bank. Really safe at 1A of the TP4052 charger.
Great video Vince =D I think you're right regards the cap being the initial fault. Cells then drained, some more than others =/ That cap size, it may be 100nF, could also be 1uF, or 10uF maybe? Likely won't make much difference I think. Either side of that area where what looked like 2 mosfets, maybe one of those had failed too? Regards desoldering batteries etc - the time they are most dangerous is when they have charge, that's where the explosive energy is, although chemical reactions can create energy too. So when dealing with a battery where its almost completely flat, there's a lot less chance of a major runaway reaction. The risk is when charging, or draining high current (or puncturing / heating a battery with charge). You might be able to get a 3rd party charge circuit for that - mod it to balance charge using a different supply maybe - but probably more hastle than its worth... I certainly wouldn't like a fault to develop in a battery like that, the fire that follows could be quite something with so many cells in such close proximity! What ever you do I wouldn't charge that unattended, although it seems like the batteries are good quality and fairly well balanced!
Thanks for the advice Chris. I'm hoping it will only need charging once a year to power that work light. If it becomes a regular thing that needs charging, then nerves will get the better of me and I will leave it be. Even when I was charging it then, I was checking for heat build up obsessively every few minutes🤣🤣 It is so complicated and I'm gutted the cap and cells didn't fix it. Thanks Gadget 👍👍👍👍👍
Buy a cheap used 2ah battery and swap out the circuit board, or even a cheap clone battery and use that circuit board. It would certainly be interesting to see if you can get it working. Great vid, really enjoyed it.
They also use the new 21000 cells instead of the older type 18950 cells so different boards used to deal with the faster charging and 50% higher output power 🔋
I know there are Makita knock-off BMSs. Maybe there's a possibility of finding one for this, or, a generic BMS that you can hookup that will prevent over discharge and over charging. You would still have to charge it with your bench power supply, but, you would have protection for the battery pack. You could even have a battery indicator with a pushbutton to check power level.
Looks like this pack is built similarly to a laptop battery. Those battery controller ICs will disable themselves as soon as the cell voltage (even on one single cell) goes too low. They can be reset, but it's not a trivial thing to do. Interestingly, I've encountered exactly the same situation when salvaging cells from a very old (~20 years) Dell battery. Out of 3 banks, one was OK (even had OK capacity), other two were totally shorted. Well, at least now you have some good quality Samsung cells which most likely can still be charged individually. I've charged dead (close to 0 V) cells before - those with at least some trace voltage present usually will still take a charge. I would charge them at low current and watch out for them while charging to make sure they aren't getting hot. I would also check for self-discharge some time after charging. Expect capacity to be degraded. I would not risk charging cells with totally 0V on them though as they can be (and usually are) internally shorted.
With the Milwaukee I've heard that the rapid charger won't charge a battery if it gets too low the regular slower charger will that's why they run deals to get all the batteries sold about twice a year so they don't die on the shelves
If the batteries are below 1v you need to take them out of the casing remove the welds. Then individually charge them at low amperage. Start with 100mil amp. until they get to 2.25v. then they will charge normally. I then wait a week after fully charged to see if the lose voltage. Any that drop below 4v after a week i get rid of and replace. Batteries that are deep drained can be renewed. Using you bench power supply. Once the get passed 2.25v you can up the amperage to .5amps. I have never had issues with Lithium cells. Its just a case of making sure the cells when in series and parallel are balanced. When you put them back in the pack they will self balance when in situ but most pack have a balancing control unit on the battery back. Just need to find a similar capacity and test the drain time.
If I was a company that doesn't want its equipment go up in flames, I'd put protection onto the controller board, that triggers when something goes wrong. You'll probably have to reset that for the charger to work again.
There is a little tab underneath one of the (+) terminal on the cell which breaks contact (hence 0.0v). You can stick a small needle under the (+) terminal and reset that breaker. This is not recommended but it is possible for educational purposes.
I don't know if someone has already commented on this, but you cannot test for a short on a battery with a multi meter, try it with a known good battery and you will see for your self. The above is also true for internal battery resistance.
I know some battary protection circuits record data on the battary and if they know the battery is dead they wont let the battery charge, had it on laptops when I try to rebuild the packs
From my previous play with 18650 cells I can say even though it’s not safe I have slow charged single cells at a time on a very slow rate NMHB of .2amps and got cells to come back to life. Your safety aside it did bring the cells back and lasted about 3 years till they finally did not want to hold a charge anymore.
Isn't that a knockoff? I have 4 of those 12.0 high output batteries and the side labels are very different from that one. Unless they use different stickers for what they ship to the UK?
Might sound silly but did you check the fuse again after you had done all the work? Maybe have another look at the board and continue to fault find. Might be more than 1 failure
try disconnecting the end terminals from the board then add cells a bank at a time starting at the negative end. you need all the cells ready to be monitored once you connect the final positive. every time you connect the BMS in the wrong order - it sees the missing bank as a fault and shuts down again.
Milwaukee M18 boards lock out as soon as you disconnect them. Doesn't really matter what you do after it crosses that low voltage threshold...it will never work again. Maybe a certified Milwaukee repair shop will have a tool to reset them...but for a DIY person Milwaukee screws you.
I call BS on they saying it was a bug. I am an authorized service centre for Milwaukee and I am constantly replacing batteries. I would replace it no question. Only time I do not replace is water damage.
The board/bms may be damaged after the capacitor issue but the bms may have turned off because of the zero battery voltage. You could try to reactivate the bms. You could try taking a jumper wire and touch it against the positive end of the battery pack before it connects to the board/bms. While holding it in place touch the other end of the jumper wire to the positive output of the board, the positive pin that connects to the charger. Hold it for a second then press the button to see if the bms has woken up. It works with laptop 18650 packs and their bms. If not your probably stuck, 10 out of 10 for effort though. Also if the bms isn't working your light will probably deplete the batteries below their safe 2.5v if you don't keep checking. I won't lie, I was waiting for a bang 😅
Alot of milwaukee tools have a Battery Gauge built into the tool itself. So you could still monitor the battery if you have a tool with gauge built in.
Bug or metal shavings is my theory. A bug is possible because some bugs zap themselves over and over again and cause a huge mess burning up. This looks like bug damage based on how wide the area is and the type of damage. Metal shavings as you can imagine and guess can cause a nasty short too but usually those burn out fast and hard. Edit: noticed the thick board coating, probably not bug damage or shavings.
I took a Makita apart few yrs back . The 1st cell always goes faulty if you run right down . Then the micro chip tells it battery is no good and to stop changing. I gave up in the end and bought a new battery
As per another post, when the BMS chip sees an issue and stops the ability to charge, this is not resettable. You can swap the charge board + chip for a cheap clone, but that's about all. They build the failure mode as permanent for safety. There was nothing you could do.
48:50 I was waiting when the ring makes contact with the batteries and start glowing red hot and leave 'nice' imprint in finger. I must say this guy is much braver than I. I would have taken ring off 'just in case'.
I know makita boards lock up and you have to replace the board. Also shows how good guarantees are any trick in the book to worm out of replacing stuff
You may call me crazy, but there was a hack to revive Ryobi LiIon battery, once it dropped below the threshold where the charger would think it was broken. Basically, you'd take a 12v battery charger, set to the 2ah setting and for just a second, tap the positive and negative. It would temp charge the cells to a high enough voltage to go above the threshold and allow to charge normally. Just editing to clarify, you'd tap the charger leads to the battery pack buss positive and negative, not individual cells.
My father has dozens and dozens of Milwaykee powertools, never used better tools! He even have about 6 Milwaykee radios/loud speakers (which uses these same batteries) and a Milwaykee pool table which he won from some draw :D
I use my bench power supply to boost lithium batteries. Normally I set it for 1A 4V and this sometimes brings those cells to life. And that's a 10 uF ceramic SMD capacitor.
I think once you disconnect the power the chip ram is wiped and the board will not allow the battery to charge as the battery has been below the minimum for safe recharging. Just a thought.
Hi Vince, I'm trying to fix a playstation 4 controller with trace damage and thought to ask you what the product was that you painted onto the plastic pcb that leads to the l1 l2 buttons, and where can I buy some? Thanks for any help
Wow them batteries where dear nice video made me smile a few times you need to regulate your charge current to about 500ma Set the voltage to 4.2 on lab supply turn current nob down connect battery and rise it up to 3 to 400ma voltage will be low but as it charges it rises.. make a spot welder MOT transformer good donner microwave really good video enjoyed it I'm in 🇬🇧 to ebikes next lol
Hi watch all your videos with great interest just to help you out a you tuber called Andy mechanic has previously done some videos on repairing milwaukee batteries and he had to replace the circuit board after he replaced the damaged cells in the battery. Keep up the fantastic educational videos.
Blimey. What a challenge that was. Brave to take apart a lithium battery but at least they are individual cells so you can't puncture them easily by mistake. Being lithium I do think you will lose charge even when not using the torch from natural discharge. So it may need charging sooner than you might think. But for continuous load it will last ages. Probably run that light for many hours. I can see why they're so expensive now given the cost of the cells and the complex circuit. My 1.5mah in my Ryobi kit is tiny in comparison yet still weighs loads. That must be seriously heavy
It was a bit nerve racking, more so with the fully charged cells!!! Yes, it is very heavy. Maybe the work light might not be an option then, time will tell 👍 It's my go to torch of choice right now when I have to do bin and recycling duties late at night, even though it weighs more than the bin/recycling 🤣🤣
Battery test lights works independently so you can check state of charge before fitting My batteries get hot when charging but never thought it was dangerous Even bought Chinese copies and seem to work well So expensive torch next revisit you will have reworked a charge jack plug within ? saves you stripping it down again to charge .. even a fly lead ?
The first think I would have done was to hook up another 18v battery (whatever brand I had to hand) and given it a 2 minute jump start. Used this method to revive a dead battery to the point the charger would charge it more than once.
Those 18650 cells does have an internal fuse against overcharge, the temperature raises too much It cuts off. You'll ser they have 0 volts. You can get around that putting It on a vice and pressing the plus nipple a little bit so it closes the circuit again. It's dangerous though, it's safer and not expensive replacing those cells. You can be sure something went south with that BMS as It demanded so much current from one or more cell that it fried.
first of all those are 21700 batteries, and second no they dont ave any internal protections on them hence the reason they are prone to bursting into flames when they fail. he even pulls the spec sheet up on them in the video and you can clearly see where it says that there is NO protection on these cells
I believe you will need to put a charge on the cells manually through a power supply and get it fully charged that way before the charger will recognize it. Put a constant ground on the battery and a temperary jump of power on the positive side at 32ish volts after each jump check the battery voltage and stop once you reach 20v. Then try it on the charger.
Are there two boards in the battery ? has the board been put back in place the correct way ? at 28:35 the copper heat sink is below the board but later it is above the board .
You can charge the battery straight from the 2 posts on top for a few minutes to wake up the cells , I usually use another 18v battery with alligator clips and then put it on the charger and it'll charge right up
I've run across problems using this type of battery with individual cells and with multiple cell battery packs in both usage and charging. In the case of your pack, each battery cell has a potential maximum voltage of 4.2 volts with a capacity of 4.0 Ahr or 4000 mAH per cell, so 3 cells in a parallel circuit = 4.2 volts @ 12 AHr or 12000 mAH. Now put 5 groups of 3 cells parallel per group in a series circuit and you end up with a maximum of 21 volts @ 12 AHr or 12000mAH @ full charge at peak battery life. I believe the industry standard minimum safe working voltage of that type of battery is 3.5 volts so the pack is considered discharged at 18 volts. The circuit board for that battery pack is likely designed to disallow any charging if the voltage has dropped below 18 volts.
Have you traded on the Milwaukee charger again yet because since you got the voltage that it needs back into the battery the charger is looking for above 16 V to charge the battery the Milwaukee charger might work now
I had this with a craft work battery 18v 5 cells dead so priced up replacement of them worked out cheaper to buy another 18v battery separated all the batteries and rebuilt into my battery pack with everything the same worked perfectly for a bodge job all the spot welds remove and soldered new strips on took a day to do new life in old combi drill/screwdriver. And pcb for this from eBay 11.59
you should be charging at 4.2 volts per cell, at a low current until they come up to 3.2 volts. Then you can charge them like a bank at the 18v charge current. one of the banks may have bad cells as it was shorted. They all likely have degradation from being shorted so long. you can also check individual cell voltages, which is very helpful to identify dead cells. You need to charge each cell to see how much of your capacity you can recover. These may have protection circuits which is why you can't take measurements.
You are priceless! You need to start a don’t try this at home channel ! Starts with : Not sure if this is going to work??? Buys the 12 amp hr battery! Buys the cheapest Milwaukee light ! Doesn’t own any other Milwaukee tools ! Complains how expensive they are ! Has his wedding ring on oblivious to the fact he could accidentally weld his finger to battery ! You remind me of my old School teacher ! Mr. Arnold ! Of course Students remember him as just Arnie !
Spoiler Saver
Please remember that this is just for entertainment, what you will see in this video IS DANGEROUS!!!! Please do not copy anything that you see!
I hope you enjoy it.
.
It won’t let me add the link on here but it seems there are sellers on eBay with replacement BMU circuit boards for that battery
Already salvaged a few 18650 from a power tool battery, just one out of 10 was bad, useful cells to have hanging around I am powering my bike lights off them :), also I agree if you don't know what you are doing don't play with them, and definitely don't solder them.
You can get the nickel strip and mini spot welder to rebuild the pack... the batteries i`d use laptop cells for it... :)
I love listening to British people talk!
Pro tip: take off your wedding ring when working on energized circuitry - or get a silicone ring. You could easily lose that finger if the battery welded itself to the ring. I still have a large scar from a metal watch-band that exploded when working on a car near the starter (the battery lead is always hot). I cringed every time you touched the sides of the battery with your ring on. Stay safe, I love the content, cheers!
More people to like this so he sees it
Nearly mentioned the same thing in my comment Thomas...couple of years ago I managed to short a laptop cell on my ring and suffered with severe burns for weeks - super heating to say the least!
Aka: Don't get married if you wanna live. 😂😂😂
Very good comment. However funny it would be to say "I'm watching 9finger Vince" I would rather Vince keeps all his fingers 😁
Nothing like a battery burn to wake you up! I worked on cell packs for years as you say first rule take your watch and ring off!!
Vince when you're using low melt solder be sure to add flux to help it flow and mix in with the regular solder. It makes a huge difference! :)
I have zero reason to watch this
I just watched the whole thing for some reason and found it very interesting! Thanks
these videos are so satisfying and they help me settle down to sleep
Great video!
The circuit board is for balancing the cells, if you charge a few cells, the voltage will drop because it's being redistributed over all cells. Either connect the battery to a full other battery(with enough discharge) or charge each cell separate bypassing the board. Smart chargers will most likely detect the battery once it's about 15Volts
The mosfet besides the cap is probably blown. You can replace it with a mosfet from taken a motherboard. Measure in diode mode between source and drain, you should get 0.4 to 0.7 V.
Yeah my thoughts aswell. I would've checked the pads where the cap was, see if there is still a short with the cap removed. That mosfet looks like it took some heat and might have shorted.
Time to buy a Mini battery spot welder. A lot less chance of heat damage to batteries. Thanks for the Vids Cuzz. Rockford,IL USA
I have worked with a lot of failed 18/36v batteries. I normally use a current limited supply across the whole battery set to the equivalent of 2.5v per cell and the current limit at 50ma per cell (150ma for 3 in parallel). Usually find most of the cells quickly (mins not hrs) rise to 2.5v if they haven't leaked and started rusting out. I find the bms is often the problem or is deliberately blocking re-use due to past excessive discharge. I end up discarding typically one bank per battery at most.
One trick to make the solder stick to the battery ends is to scratch it before soldering. So the solder has a mechanical connection with the battery. I repaired a vacuum like that and is going really strong. This will also make it easier to solder, you don't need to apply so much heat because the solder will flow to the scratches and grab into.
Solder simply needs clean, bare metal and the correct flux. Solder uses a molecular level connection. No need to rough up the surface.
Protip when using continuity in-circuit: Always check both ways. Your meter uses voltage to check for continuity. However, the circuit may have voltages across two points that will provide a false reading. I learned this fairly quickly when doing car fuses. All fuses read perfectly, including blown ones, until out of circuit.
Always happy to make some time to relax and watch Vince play with dangerous things!
The safety issue with charging cells that have gone that flat is simple. They need reforming. You can do that by charging them @50mA per cell up to a voltage of 2.6 and keep them there awhile. That should recondition the cells adequately enough. The board and it's components may be another story entirely. If it has a fault lockout like other commenters have mentioned it could be completely rooted. The real acid test for the cells is to charge them and see if they keep it without self discharge over a reasonable amount of time.
I really enjoy your warts and all videos on repair strategies. It's always entertaining. I really enjoy the dépistage and admire how you refuse to quit
If cells drop below 2.7v the bms ic will destroy circuit for protection. I guess that ic is BQ and they will destroy the fuse near cells to protect them and some newer BQ types will lock themselves. In this case you can charge them from output so it’s look like that just ic is locked. You can try unlocking it by shorting data and clock to ground. If that doesn’t help, you will need to reprogram it. But, if you want to program it, be aware that in mostly cases, manufacturers protect them with the password.
So, in fact they are self destructing when they think something serious is wrong …
Interesting. I was speculating the chip next to the replaced cap was effectively a system management controller that had gone brain dead. I assume it talks to the charger to relay system health (of the battery) and it was bad
It does not "destroy" the circuit, it just shuts off the mosfets so no additional power can be drained by the tool.
On these batteries unless its something serious the IC bricks itself after 3 failed charge attempts.
Good luck for anyone trying to hack these and unlock them. Tons of talented people have tried but Milwaukee has put lots of money into making them unfixable.
However what you can do is get a new grey market board if you've charged the cells.
This bricking behavior is why if it flashes red and green due to low charge it's important not to attempt again but to manually charge it back up.
All of this is pretty readily available info.
33:15 never thought about that, only 3 out of all of those batteries, kinda thought all went bad at same time. 👍 Good info
Very strange how 3 survived. Cheers Paul 👍
I hate to chime in so late my friend, but I couldn't help notice the fuse was possibly the cause of the scorching. A damaged trace was loose and all the solder appeared to have vapourized.Thrown off by the continuity test you did as I have been many times. Funny that the fuse didn't blow from whatever the cause. Not that the resoldering of that fuse would solve the problem of course, but I bet the board would come to life for a better prognosis. These HD12 are very expensive. I have one on my bench that reads 17V all groups of 3 are in at 3.36V and yet the first LED blinks 8 times. I have not been able to find any damage to the board. Going to have a much closer look at the PCB and all. Here in Canada these cost $379 CAD
Don't know if this has already been mentioned but Doctor Lefthandthread replaced a Milwaukee battery CB with a knock off one to revive the unit in one of his videos, so they must be available. Love the videos Vince, keep 'em coming.
Hi there my name's TheCod3r from your mate TheCod3r dcom and in this comment today is another comment telling you to keep up the great work! Looking forward to this one
I know its over a year later and you may not care, but the Cap value on my board is 10uf. It is suprising that it's that large so I checked on the 12ah and double checked on the 8ah board. They are both showing 10uf. I have been working on one of these 12ah for a while now off and on. The boards on these HO packs are strange. Both the 12ah and the 8ah, once I removed the power from them to do a reset now they will not power on. Both boards did just like yours. No power. This maybe a HO pack issue?
Just throwing it out there as I try to edit my video while troubleshooting mine. I hope collectively we can figure out much more about them. I do know the cells in these has issues with the 1st gen and Samsung now has the V3 of this cell out now. Take care!
Well this way by far one of your most risky and dangerous trying to fix videos
Unfortunately you cannot measure the resistance of a power source like a battery with your ohm meter. As it uses voltage to determine the resistance, it will read wrong if there is voltage.
I always get enjoyment from your videos, thanks again, Dave
I just bought myself a nice new set of Makita LXT tools (SDS, Combi Drill, Screw Gun, Angle Grinder and Circular Saw) and I was gobsmacked. £120 for a battery and charger and they don't even come with the tools. Really is unbelievable how much they can charge for a few basic 18650s
Usually in this case, when you don't know the capacitor value, I would look up a nearest ic's datasheet.
Ayr is also a seaside town on the west coast of Scotland.
Indeed it was probably Scots who named it in Aus, just like Perth etc.
Defiantly worth getting a battery welder, even just a small portable one as they are so much easier to use with these cells. Have you thought of just getting another 3P 5S BMS to manage the charging? It wont do all the LED's but may let you charge from the Milwaulkee charger
You would need a k welder with supercaps or else you can’t weld 0.3mm factory nickel strip
The black burnt thing you IPAed off was the bug- a worm or slug. Cant check resistance on a battery as it is a power source and will screw up the resistance measurement. The sets of parallel batteries ALTERNATE polarity - think batteries end to end like in a flashlight except in this case back and forth. Recharging fully discharged lithium cells is NOT unsafe (I've recharged HUNDREDS of fully discharged cells and lipos), the full discharge just reduces battery capacity sometimes all the way down to NO capacity.. The dangerous thing you did was to REVERSE POLARITY most of the other parallel sets. The way I rescue packs is to use a TP4056 and charge each parallel bank slowly. Your cells are probably around 4Ah and when in parallel (by threes) will be 4Ah x 3 or 12Ah and charging lithium batteries is safe at up to 1C so 12Amps per bank. Really safe at 1A of the TP4052 charger.
Been waiting for some new Vince to watch whilst I'm stuck on isolation!!
Great video Vince =D I think you're right regards the cap being the initial fault. Cells then drained, some more than others =/ That cap size, it may be 100nF, could also be 1uF, or 10uF maybe? Likely won't make much difference I think. Either side of that area where what looked like 2 mosfets, maybe one of those had failed too? Regards desoldering batteries etc - the time they are most dangerous is when they have charge, that's where the explosive energy is, although chemical reactions can create energy too. So when dealing with a battery where its almost completely flat, there's a lot less chance of a major runaway reaction. The risk is when charging, or draining high current (or puncturing / heating a battery with charge). You might be able to get a 3rd party charge circuit for that - mod it to balance charge using a different supply maybe - but probably more hastle than its worth... I certainly wouldn't like a fault to develop in a battery like that, the fire that follows could be quite something with so many cells in such close proximity! What ever you do I wouldn't charge that unattended, although it seems like the batteries are good quality and fairly well balanced!
Thanks for the advice Chris. I'm hoping it will only need charging once a year to power that work light. If it becomes a regular thing that needs charging, then nerves will get the better of me and I will leave it be. Even when I was charging it then, I was checking for heat build up obsessively every few minutes🤣🤣 It is so complicated and I'm gutted the cap and cells didn't fix it. Thanks Gadget 👍👍👍👍👍
@@Mymatevince No worries! Did you see comments below from a few people regards a replacement charge board =O
I did Chris, they are on there way from China 👍👍
Being not an expert in this field of electronics, but have to admire the perseverance. Sorry it didn't work out after all those expenses.
Buy a cheap used 2ah battery and swap out the circuit board, or even a cheap clone battery and use that circuit board. It would certainly be interesting to see if you can get it working. Great vid, really enjoyed it.
You can’t swap a 2ah, they use different bms
only the high output 6 and 8ah use the same bms
2ah and 5ah have different bms
They also use the new 21000 cells instead of the older type 18950 cells so different boards used to deal with the faster charging and 50% higher output power 🔋
I know there are Makita knock-off BMSs. Maybe there's a possibility of finding one for this, or, a generic BMS that you can hookup that will prevent over discharge and over charging. You would still have to charge it with your bench power supply, but, you would have protection for the battery pack. You could even have a battery indicator with a pushbutton to check power level.
Hold the button five seconds to reset board then put on charger then push button once more then remove from charger and the put back it should work
Looks like this pack is built similarly to a laptop battery. Those battery controller ICs will disable themselves as soon as the cell voltage (even on one single cell) goes too low. They can be reset, but it's not a trivial thing to do.
Interestingly, I've encountered exactly the same situation when salvaging cells from a very old (~20 years) Dell battery. Out of 3 banks, one was OK (even had OK capacity), other two were totally shorted.
Well, at least now you have some good quality Samsung cells which most likely can still be charged individually.
I've charged dead (close to 0 V) cells before - those with at least some trace voltage present usually will still take a charge. I would charge them at low current and watch out for them while charging to make sure they aren't getting hot. I would also check for self-discharge some time after charging. Expect capacity to be degraded.
I would not risk charging cells with totally 0V on them though as they can be (and usually are) internally shorted.
Great video! Where can that ruler be purchased from? Thanks 👍🏻
With the Milwaukee I've heard that the rapid charger won't charge a battery if it gets too low the regular slower charger will that's why they run deals to get all the batteries sold about twice a year so they don't die on the shelves
I would like to see you fix the board on that battery just because I know you can I enjoy your videos Vince thank you very much
Hi Vince, I learned a lot from this. Thanks for doing the video.
Use the Jessa Jones cap delete tool an exacto knife!
If the batteries are below 1v you need to take them out of the casing remove the welds. Then individually charge them at low amperage. Start with 100mil amp. until they get to 2.25v. then they will charge normally. I then wait a week after fully charged to see if the lose voltage. Any that drop below 4v after a week i get rid of and replace. Batteries that are deep drained can be renewed.
Using you bench power supply. Once the get passed 2.25v you can up the amperage to .5amps.
I have never had issues with Lithium cells. Its just a case of making sure the cells when in series and parallel are balanced. When you put them back in the pack they will self balance when in situ but most pack have a balancing control unit on the battery back.
Just need to find a similar capacity and test the drain time.
If I was a company that doesn't want its equipment go up in flames, I'd put protection onto the controller board, that triggers when something goes wrong. You'll probably have to reset that for the charger to work again.
There is a little tab underneath one of the (+) terminal on the cell which breaks contact (hence 0.0v). You can stick a small needle under the (+) terminal and reset that breaker. This is not recommended but it is possible for educational purposes.
I don't know if someone has already commented on this, but you cannot test for a short on a battery with a multi meter, try it with a known good battery and you will see for your self.
The above is also true for internal battery resistance.
great job ! lots of patience vince .....
I know some battary protection circuits record data on the battary and if they know the battery is dead they wont let the battery charge, had it on laptops when I try to rebuild the packs
From my previous play with 18650 cells I can say even though it’s not safe I have slow charged single cells at a time on a very slow rate NMHB of .2amps and got cells to come back to life. Your safety aside it did bring the cells back and lasted about 3 years till they finally did not want to hold a charge anymore.
Isn't that a knockoff? I have 4 of those 12.0 high output batteries and the side labels are very different from that one. Unless they use different stickers for what they ship to the UK?
hi mate were did you get the ruler that was in the video
40:23 Battery spot welder is dirt cheap
Might sound silly but did you check the fuse again after you had done all the work? Maybe have another look at the board and continue to fault find. Might be more than 1 failure
Yeah I think he should check the board in more detail. He could get it fixed.
try disconnecting the end terminals from the board then add cells a bank at a time starting at the negative end. you need all the cells ready to be monitored once you connect the final positive. every time you connect the BMS in the wrong order - it sees the missing bank as a fault and shuts down again.
Milwaukee M18 boards lock out as soon as you disconnect them. Doesn't really matter what you do after it crosses that low voltage threshold...it will never work again.
Maybe a certified Milwaukee repair shop will have a tool to reset them...but for a DIY person Milwaukee screws you.
I can't believe you think you measured the resistance of the cells with your DMM
That was a great repair, Vince. Not quite what you wanted, but nonetheless it is working. 👍👍👍👍
I call BS on they saying it was a bug. I am an authorized service centre for Milwaukee and I am constantly replacing batteries. I would replace it no question. Only time I do not replace is water damage.
I will check on my 18v alot smaller battery tomorrow morning, how many cells should do no difference would it?
The board/bms may be damaged after the capacitor issue but the bms may have turned off because of the zero battery voltage.
You could try to reactivate the bms.
You could try taking a jumper wire and touch it against the positive end of the battery pack before it connects to the board/bms.
While holding it in place touch the other end of the jumper wire to the positive output of the board, the positive pin that connects to the charger.
Hold it for a second then press the button to see if the bms has woken up.
It works with laptop 18650 packs and their bms.
If not your probably stuck, 10 out of 10 for effort though.
Also if the bms isn't working your light will probably deplete the batteries below their safe 2.5v if you don't keep checking.
I won't lie, I was waiting for a bang 😅
Your voice is so soothing
Great video buddy, was hooked watching this, well waiting for the “BANG” haha, unlucky though, was a great effort
Hey Vince, great video as always. I wanted to ask, what it the blue mat you work on called?
Alot of milwaukee tools have a Battery Gauge built into the tool itself. So you could still monitor the battery if you have a tool with gauge built in.
Bug or metal shavings is my theory.
A bug is possible because some bugs zap themselves over and over again and cause a huge mess burning up. This looks like bug damage based on how wide the area is and the type of damage.
Metal shavings as you can imagine and guess can cause a nasty short too but usually those burn out fast and hard.
Edit: noticed the thick board coating, probably not bug damage or shavings.
I took a Makita apart few yrs back .
The 1st cell always goes faulty if you run right down .
Then the micro chip tells it battery is no good and to stop changing.
I gave up in the end and bought a new battery
As per another post, when the BMS chip sees an issue and stops the ability to charge, this is not resettable. You can swap the charge board + chip for a cheap clone, but that's about all. They build the failure mode as permanent for safety. There was nothing you could do.
Killed it! Good work!
Hi sir when you say bug damage do you mean insect or beatle damage shorting the board ?
The board is about £5 on eBay. As far as I can tell ..
Peace and love brother 👍🏻☮♥️
Jesus loves you
Nice video , BMS has tripped 👍👍👍👍 the cap could be 1uf 10 uf
48:50 I was waiting when the ring makes contact with the batteries and start glowing red hot and leave 'nice' imprint in finger. I must say this guy is much braver than I. I would have taken ring off 'just in case'.
You can't check batteries for shorts by beeping them out. And batteries are supposed to be shorted, which means they have a low internal resistance.
I know makita boards lock up and you have to replace the board. Also shows how good guarantees are any trick in the book to worm out of replacing stuff
You may call me crazy, but there was a hack to revive Ryobi LiIon battery, once it dropped below the threshold where the charger would think it was broken. Basically, you'd take a 12v battery charger, set to the 2ah setting and for just a second, tap the positive and negative. It would temp charge the cells to a high enough voltage to go above the threshold and allow to charge normally. Just editing to clarify, you'd tap the charger leads to the battery pack buss positive and negative, not individual cells.
My father has dozens and dozens of Milwaykee powertools, never used better tools! He even have about 6 Milwaykee radios/loud speakers (which uses these same batteries) and a Milwaykee pool table which he won from some draw :D
Nobody ask you
I use my bench power supply to boost lithium batteries. Normally I set it for 1A 4V and this sometimes brings those cells to life. And that's a 10 uF ceramic SMD capacitor.
I think once you disconnect the power the chip ram is wiped and the board will not allow the battery to charge as the battery has been below the minimum for safe recharging. Just a thought.
Hi Vince,
I'm trying to fix a playstation 4 controller with trace damage and thought
to ask you what the product was that you painted onto the plastic pcb
that leads to the l1 l2 buttons, and where can I buy some?
Thanks for any help
Excellent video my friend! 👍😊
Did you remember to to check that white e fuse again as it showed that showed it wasn't open due to a shorted capacitor right next to it.
Wow them batteries where dear nice video made me smile a few times you need to regulate your charge current to about 500ma
Set the voltage to 4.2 on lab supply turn current nob down connect battery and rise it up to 3 to 400ma voltage will be low but as it charges it rises.. make a spot welder MOT transformer good donner microwave really good video enjoyed it I'm in 🇬🇧 to ebikes next lol
Hi watch all your videos with great interest just to help you out a you tuber called Andy mechanic has previously done some videos on repairing milwaukee batteries and he had to replace the circuit board after he replaced the damaged cells in the battery. Keep up the fantastic educational videos.
Blimey. What a challenge that was. Brave to take apart a lithium battery but at least they are individual cells so you can't puncture them easily by mistake. Being lithium I do think you will lose charge even when not using the torch from natural discharge. So it may need charging sooner than you might think. But for continuous load it will last ages. Probably run that light for many hours. I can see why they're so expensive now given the cost of the cells and the complex circuit. My 1.5mah in my Ryobi kit is tiny in comparison yet still weighs loads. That must be seriously heavy
It was a bit nerve racking, more so with the fully charged cells!!! Yes, it is very heavy. Maybe the work light might not be an option then, time will tell 👍 It's my go to torch of choice right now when I have to do bin and recycling duties late at night, even though it weighs more than the bin/recycling 🤣🤣
Ayr is also a town in Scotland that is about 20 mins from where I live.
Battery test lights works independently so you can check state of charge before fitting
My batteries get hot when charging but never thought it was dangerous
Even bought Chinese copies and seem to work well
So expensive torch next revisit you will have reworked a charge jack plug within ? saves you stripping it down again to charge .. even a fly lead ?
The first think I would have done was to hook up another 18v battery (whatever brand I had to hand) and given it a 2 minute jump start.
Used this method to revive a dead battery to the point the charger would charge it more than once.
Vince you are a very good man and again i loved that video so much❤️
Individual cells can short on the inside, you can replace single cells, you just need to find a way to spot weld them back :)
Those 18650 cells does have an internal fuse against overcharge, the temperature raises too much It cuts off. You'll ser they have 0 volts. You can get around that putting It on a vice and pressing the plus nipple a little bit so it closes the circuit again. It's dangerous though, it's safer and not expensive replacing those cells. You can be sure something went south with that BMS as It demanded so much current from one or more cell that it fried.
first of all those are 21700 batteries, and second no they dont ave any internal protections on them hence the reason they are prone to bursting into flames when they fail. he even pulls the spec sheet up on them in the video and you can clearly see where it says that there is NO protection on these cells
I believe you will need to put a charge on the cells manually through a power supply and get it fully charged that way before the charger will recognize it. Put a constant ground on the battery and a temperary jump of power on the positive side at 32ish volts after each jump check the battery voltage and stop once you reach 20v. Then try it on the charger.
Did this on a black and decker battery that was part of a job lot of DIY stuff. Basically got everything else for free.
Are there two boards in the battery ? has the board been put back in place the correct way ? at 28:35 the copper heat sink is below the board but later it is above the board .
You need to look at the board for jumper pins. I think you need to reset the board.
You can charge the battery straight from the 2 posts on top for a few minutes to wake up the cells , I usually use another 18v battery with alligator clips and then put it on the charger and it'll charge right up
I love how a flashlight is called a torch?
I've run across problems using this type of battery with individual cells and with multiple cell battery packs in both usage and charging. In the case of your pack, each battery cell has a potential maximum voltage of 4.2 volts with a capacity of 4.0 Ahr or 4000 mAH per cell, so 3 cells in a parallel circuit = 4.2 volts @ 12 AHr or 12000 mAH. Now put 5 groups of 3 cells parallel per group in a series circuit and you end up with a maximum of 21 volts @ 12 AHr or 12000mAH @ full charge at peak battery life. I believe the industry standard minimum safe working voltage of that type of battery is 3.5 volts so the pack is considered discharged at 18 volts. The circuit board for that battery pack is likely designed to disallow any charging if the voltage has dropped below 18 volts.
Around the capacitor it looks like a few MOSFET's en they may be worth checking. They are the ones switching the power.
Have you traded on the Milwaukee charger again yet because since you got the voltage that it needs back into the battery the charger is looking for above 16 V to charge the battery the Milwaukee charger might work now
vince now you have met the proper company get them to sponsor you
I had this with a craft work battery 18v 5 cells dead so priced up replacement of them worked out cheaper to buy another 18v battery separated all the batteries and rebuilt into my battery pack with everything the same worked perfectly for a bodge job all the spot welds remove and soldered new strips on took a day to do new life in old combi drill/screwdriver. And pcb for this from eBay 11.59
Another great video Vince. Love your content ! Pity this one didnt result in a fix, but well done for trying ! Have Fun !
you should be charging at 4.2 volts per cell, at a low current until they come up to 3.2 volts. Then you can charge them like a bank at the 18v charge current. one of the banks may have bad cells as it was shorted. They all likely have degradation from being shorted so long. you can also check individual cell voltages, which is very helpful to identify dead cells. You need to charge each cell to see how much of your capacity you can recover. These may have protection circuits which is why you can't take measurements.
You are priceless! You need to start a don’t try this at home channel ! Starts with :
Not sure if this is going to work??? Buys the 12 amp hr battery! Buys the cheapest Milwaukee light ! Doesn’t own any other Milwaukee tools ! Complains how expensive they are ! Has his wedding ring on oblivious to the fact he could accidentally weld his finger to battery !
You remind me of my old School teacher ! Mr. Arnold ! Of course
Students remember him as just Arnie !
It was crazy watching this guy tapping the top of that battery circuit board with that ring on his finger...