Milwaukee Battery Won't Charge Fully - FIXED!
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- เผยแพร่เมื่อ 16 ก.ย. 2024
- This M18 battery would only charge up to 3 bars. Walk through on how to fix this problem!
Buck Converter Used - amzn.to/3qCQMQo
Power Supply - amzn.to/3P4KjaZ
Battery Clamps - amzn.to/3PjwOUJ
Multimeter - amzn.to/3qzkYvC
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The cells in these M18 batteries, as well as many other electronics like ebikes and laptops are 18650 batteries. I already had an 18650 battery charger since I use them in my flashlights and other devices. Just jumped the charger to the lower voltage bank on my M18 9.0, charged that bank to the same voltage as the other banks. Drained the battery to 3 bars, recharged on the M18 charger and works almost as good as new now! 15 minutes worth of work and saved $300 from buying a new one.
I have a m18 8.0 xc will this method work for me? I basically rigged my m18 to run a led light/work light and I let it run til it turned off. Went to charge just went to green light on the charger. I opened up the battery pack and I have 4 cells that are dead
Really appreciate this video. I build the trickle charger set it to 4 V and 1.75 amps and was able to save my Milwaukee 9.0 and a Dewalt 5.0 batteries. Both hold their charge, discharge normally in use, and recharge normally too - green light on the charger and full bars on the battery. Thanks a lot for putting this out and all the details.
I'm glad it worked for you. Thanks for the comment!
Is it a permanent fix or do you have to constantly do that ?
It will likely happen again. However, I got another year of use out of this one before it started acting up again!
I just found this video because my 8AH battery stopped working. It worked fine last fall but won’t work this spring. The symptoms you have are exactly the same as mine.
I disassembled it and tested the cell groupings the same as you did and I also had a single group at 3.4 volts. Based on your procedure, I charged it up using an old 5.1 volt transformer for a phone. I cut the end off and simply inserted a rectifier diode which reduces voltage by 0.7 volts which which left me 4.4 volts. This is a very low amperage output so it took 2 hours to get the voltage up to 3.6 volts at which point, all 4 light would light. I put the battery back together and everything works fine. Thank you. This saved me $150.
Glad it worked for you!
Appreciate your video I followed it and it seems to be working well to bring my batteries back up to 4 bars.
I’m currently working on one of my batteries at the moment. Was curious since the video is a year old if you had to repeat this practice any to keep your batteries from doing this again.
Thanks!
This battery did great for about a year, but has since developed a different problem, unfortunately!
Great video! Thank you for sharing! I have (4) 12ah HO and (3) 8ah HO batteries that i marked 3 bars full and 2 bars full so i know they arent half charged when i hit the button (they are but i cant fix that until i revive the low cells).
What really frustrates the hell out of me with Milwaukee is that circuit board on top of the cells is supposed to be a BMS (Battery Management System). It is supposed to automatically balance the different cells internally, as well as protecting the battery from over charging and over discharging.
I have a really good battery charger for hobby car /airplane batteries and it does just that. With multiple cell batteries, not only does it charge them but it automatically balances the cells. Im going to see if I can wire that thing up to revive my crap batteries.
Thanks for the comment!
Yeah, I have this exact same battery and am having the same problem. Looking around on the internet, apparently this is a SUPER common problem. I think you nailed it... the BMS just isn't working properly.
I got a 12amp that only goes 2 bars did it work ??
I had this happen on a 12.0 battery, it wouldn’t charge completely. I left it on my rocket light till it died, then put back on charger and it fully charged.
Thanks for sharing.
I have the same problem right now
I am completely unimpressed with the quality of the HO series batteries. Yeah, they have a great c-rating so you can get good power out of the saws and stuff but... apparently they suck pretty hard in the charging management department. Honestly, I'd rather have two XC 5.0 batteries than one HO 8.0
After some months of use, the HO 6.0 batts don't appear to have the same problem. I've got three of them and have them run them all down completely multiple times and haven't encountered this problem with any of them yet.
@oneandy2 Thanks for the follow up!
This is a Fantastic video thank you for taking the time. These Milwaukee batteries are not alone with this issue and I'm certain this video will also help those using other tool manufacturers using cordless technology. I've subscribed & liked 🏁
Thank you!
To unscrew you need a bit with a hole or drill the pin off carefully to maintain the tines in the screw.
Yes, a security Torx is required.
I've got an old R.C. plane battery charger that was adjustable. I bet that would perfect
Well done video. What are using to power the buck converter. I have this issue all the time and finally decided to try to fix the batteries instead of buying new ones.
Thank you! I used a 18v power supply from a cheap 18v tool that no longer worked.
@@KonaBlueSVT Thanks Kona!
@@KonaBlueSVT You have been so helpful, I thought I would push my luck. Would this work to power the buck converter. Super long url. www.amazon.com/Waterproof-Transformer-Adapter-100V-265V-Computer/dp/B07MZP9247/ref=sxin_16_pa_sp_search_thematic_sspa?content-id=amzn1.sym.c8697a08-4071-4b95-a6c6-18057bcdb898%3Aamzn1.sym.c8697a08-4071-4b95-a6c6-18057bcdb898&cv_ct_cx=12v%2Bpower%2Bsupply&keywords=12v%2Bpower%2Bsupply&pd_rd_i=B07MZP9247&pd_rd_r=887ad41e-105b-4760-8d0c-48d7a7067a1a&pd_rd_w=vVENg&pd_rd_wg=qyow8&pf_rd_p=c8697a08-4071-4b95-a6c6-18057bcdb898&pf_rd_r=VZYJP9JSX8GA3BYNQY4M&s=electronics&sbo=RZvfv%2F%2FHxDF%2BO5021pAnSA%3D%3D&sr=1-1-364cf978-ce2a-480a-9bb0-bdb96faa0f61-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE2STJJMU43SE82SSZlbmNyeXB0ZWRJZD1BMTA0MTQ4NjMyOElIUUlGSDFTNjYmZW5jcnlwdGVkQWRJZD1BMDg5NzgyNE1SQlBKTlczSFEyUCZ3aWRnZXROYW1lPXNwX3NlYXJjaF90aGVtYXRpYyZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1
Obviously I am not an electrician but I did wire a house once. And it hasn't burned down yet.
All I can find is a transformer that pulses, even DC. Is your 18v 1A transformer a static output of some sort??
The 8.0 batteries are particularly bad both of mine and a guy i work with only the 8.0 does this not the 2-6ah those all work great
same as those 12Ah
same cells
How do you make the connection from the end of the power supply cord to the wires that go into the Buck converter?
I used an eyelet style connecter for the ground on the outside and a small round style connector for the center positive.
Awesome I got a 12.0 high demand doing the same thing hopefully I can revive it
Did it work?
Xc 8.0 same issue
Update: xc8.0 always charged only 3 bars. Did exactly what was described in this video, now the pack charges to 4 bars. Thanks a bunch !
Glad it worked for you!
I can’t find your video on how you made the battery charger. Can you please link it for me?
th-cam.com/users/shortsW-Yq8_o48Yo?feature=share
Thank you boss!
One more question for you. After balancing them, how long do they stay corrected? Have they fallen back out of balance since you made the video?
So this one actually just started giving me issues again. About 10 months later.
My m18 xc 3.0 wont do anything except the first red light stays lit. It wont shut off it just stays solid red. Do you know why?
Could you use a 12v power adaptor? You''ve stepped it down to 4v when charging so seems like you could use a 12v right?
Yes, I just used 18v for the potential for higher voltage in other applications.
Thank you kindly. Super informative video easily explained. @@KonaBlueSVT
@kirkdesmond Thanks for the comment!
Couldn't you drain the outside cells to the approximate the level of the lower cell easier than building a custom charger?
The circuit board won't allow them to charge if they are under a certain voltage. So they low ones must be brought above that voltage in order to still use the factory charger.
@@KonaBlueSVT ah....Roger that
Honestly this is too much to take in and a ridiculous amount of work (and I love to take apart stuff and solder and junk) for such a simple flaw. Just a buy a new one and return it with the defective battery. It’s really the only way since these are wayyy too much money. If it was $10 a battery, then no, but more than that then this is the way, child.
To each their own. I got a new battery, AND revived this one for free.
@@KonaBlueSVThow did you get a new one ? Warranty ?
Yes, Milwaukee has awesome customer service.
@@KonaBlueSVT I’ve had mine for 2 ish years. It’s Been through a lot, wonder if they’ll still do anything with it.
@braydonkirnec1853 depending on which series it is, they have a 2 year or 3 year warranty. Check out this video for more information on that th-cam.com/video/RRR4mEqXO1w/w-d-xo.htmlsi=D5o7sDBK5oWmAP8X
Can you please explain why you put the positive lead to where the negative was to charge the second row?? I'm confused 🤔🤔🤔 appreciate your video and time👍
Because they are in series & parallel. See this link if you are unsure what that means batteryguy.com/kb/knowledge-base/connecting-batteries-in-series/
Ibe Always wanted to be able to build stuff like that....
So do it
After a while , you will have to do balancing again . Since self - discharge occurs in this cell . Only replacement with new elements will help .
2 months in, so far, so good.
@@KonaBlueSVT So you often use this battery . I had the same problem with the 9Ah battery
Yes, I've been using it weekly. I am sure it will fail again at some point. The 9AH had all kinds of problems, to the point that they discontinued them.
@@KonaBlueSVT You can check for the sake of experiment . Charge it to 100% and don't use it for ten days. And you will again have a voltage drawdown on the problem cell.
@@lutsevyat I will try that
I had the same problem, 3 bars and the charger would go to green. I fixed the problem by jumping the battery to my 48v electric golf cart battery pack for about two minutes and now the battery shows 4 bars. Haven't checked the battery lately to see if it still holds the charge but it did after 2 hours. Hope this works for you.
This is the most dangerous instruction I have found on the internet!!!
I hope you have good fire insurance?
@@Popajaja I'm still here!
Don't do this.
Mine has same problem now 😅. 12ah battery for the chainsaw
Ingenious!! So this permanently fixes it? What do you think caused it to not charge? Thanks!
Sometimes an issue with a tool, but my guess is it's using it with a tool that has a heavy power draw that pulls the charge down quicker than the shut off can shut it down.
For how long it solved your issue? Did it show up again? If yes - when?
This one went about 10 months before it started having issues again
my 12.0 only charges to the 3rd light if i discharge the 12.0 with a light adapter think is will fully charge back up?
Sometimes, this works, but you may have to balance the cells like I did in this video.
@KonaBlueSVT. So I am having a somewhat similar problem. I am guessing its because I left my batteries on the charger too long after they were charged. Now they say they are fully charged, but a 9.0 can last me 5 minutes maybe on a weed eater. Is this something I can check and fix with this? Also where could I get or make a battery charger like that?
If they are fully charging, but just draining quick. You unfortunately probably just have a bad battery. I don't know of of a way to fix that.
What causes almost new, unused Milwaukee M18/12 Aḫ to get a large voltage difference across the cells? Maybe the battery's internal electronics are slowly "stealing" electricity, and the battery has been in storage for a very long time? I buy very cheap such "defective" batteries and I didn't notice that the problem is in Li-Ion cells 5 x (3 x 4Ah connected in parallel).
Likely stored for a long time without being charged. Once the cell falls below a threshold, the board won't charge it anymore.
@@KonaBlueSVT I measured and the biggest difference in voltage is 0.5-0.6V and that's why only three diodes lit up and the charger marked the battery as full. Cells that fall below 2.5V are permanently damaged and unsafe, so I no longer use them (short circuit and possibility of fire). The intelligent Milwaukee charger recognizes damaged cells and marks the battery as broken.
Great video. However, I don't understand your voltage readings. 3 times 4.00 volts is 12 volts. However, this is an 18 volt battery.Where do you get the extra 6 volts? Also, 2 groups of 4, and 1 group of 2 batteries. How does the 2 group get 4 volts? Thanks, Barry
I mis-spoke at the beginning of the video. Each cell is made up of 2 batteries. There are 5 sets of 2. While they do call this an 18v battery they are actually 20v when fully charged. 4x5=20
@@KonaBlueSVT Thanks
there are 5 banks of batteries, wired serially., for a total of 20.0 volts fully charged. You tested banks 1, 3 and 5. You need to go back and check 2 and 4.
Ive been doing this method for several years now on the 12 Ah battery for the chainsaw. What happens is the battery management system marks banks as “bad” and no longer charges it. Why it decides they are bad i dont know, but clearly the bms is avoiding a fire hazard by shutting them down. I have “bad” banks 2, 3 and 4. I charged them individually using a 3 amp 4 volt supplies, it took 2 hours. The total voltage was 20.2 volts.
Everything worked great for 3 recharges and then the problem returned somewhat. This time only banks 3 and 4 were not charging. rinse and repeat 3 charges later again a problem but this time with 2 and 4.
Then i tried using an older, slow mikwaukee charger instead of the newer Fast charger type. This fixed it permanently. It takes a lot longer to charge but all the banks charge normally and fully
I also have two 8.0 batteries, always using the old slow charger and never had a problem.
Why don't these chargers balance the pack and monitor each cell as its charging. RC chargers do that and you can tell what cell is bad.
What size torx do I need, looks like my battery has tamper proof torx, the smallest I have is t10 so it must be smaller than that
I believe it was a T3 tamper proof style.
Mine Charges half way, but then flashes red and green, it doesnt say fully charged. so is it worth opening up to check it?
Flashing red & green usually means the charger detects a problem with the battery. You could open it up and check it out, but I am not sure that there would be anything you can do to fix it.
@@KonaBlueSVT yeah it means error, which can also mean things like undervolt. I have some of the compact 1.5ah M12 that have a weird issue, I disassembled it and it charges, but if I press on the bottom of it or reinstall the bottom plastic cover, it stops charging and says it's full, or flashes an error, it makes zero sense.
So, I can do this with my RC Car Charger ... So, Is it 4 Cell ?? 7.4 V or 11.1 ? & Charge at .5 amps ?
if you are charging like the video on each cell individually, it would be 1 cell, or 1S. 3.7v nominal, 4.2 fully charged
@@benmeiler9070 It doesn’t have an option for 1s. 2S 7.4v & 3S 11.1.
Just checked my 8ah battery using your method. 1st bank shows 4.11v. 2nd and third banks both show 3.72v. Can I charge the second 2 banks and be okay?
It would be worth a try. Charge them slow.
Could this be due to the charger? Two of my batteries came up with this problem recently. My 5.0 at least 3-4 years old and abused so I thought it was just it’s time. Then my newer 8.0, only a few months old, started doing that a week later. Don’t want to keep using that same charger if that’s the reason. Thanks in advance
When I talked to Milwaukee, they asked about what tool it was used in. They blamed it on that vs. the charger.
The batteries are supposed to have built-in protection chips. The tools don't really have any protection, and the chargers have minimal protections. When a battery is being used on any random device/tool, it should disconnect internally before the battery is too drained, and then the charging circuit (INSIDE THE BATTERY) should be still be able to negotiate with the charger and allow the incoming current in a safe way.
If the battery is TOO dead, as a result of the internal battery protection not disconnecting it, then there isn't enough juice left on the battery for the internal safety boards to detect it. Since the battery COULD be missing entirely, or may only have 2 out of 10 cells present, it is just safer for milwaukee if they don't allow the chargers to force current into the battery.
This is similar to a cell phone. If your phone dies, sometimes (depending on the phone and battery) you can turn it back on multiple times after the first time it shuts down on its own. It leaves that extra electricity in the battery on purpose, for the health of the battery, and to make sure the charging circuit (inside the phone and battery, NOT the wall brick) still have enough juice left to poll the sensors and regulate the charging voltage and current.
You know about phone batteries and vape batteries exploding? Well, the drill batteries are the same technology, just 2-8 times bigger if they happened to explode. So, these protection circuits are important, and the manufacturer will usually err on the side of caution, because courts have sided with the "victims" and allow their insurance companies to attack the tool/phone manufacturer to recover payments used to rebuild a house that burned down. HOWEVER, this leads to a lot of batteries that simply discharged 5% too far, then stop working, and the tool company doesn't give you any core charge on these batteries that are approaching the same cost as a car battery??
You're going to see more and more videos like this, and if you do it safely, you can save a LOT of money in the long run
How did u make the small charger?? Link please
All the components are listed in the description. Here is a video on the charger itself - th-cam.com/users/shortsW-Yq8_o48Yo?feature=share
Where is the video on how to make the charger?
th-cam.com/users/shortsW-Yq8_o48Yo?feature=share
i am trying this as we speak. bought the power converter, got it all hooked up just like you showed but i noticed that my light on the converter flashes red while yours was solid red when charging... am i doing something wrong? seems to be charging...
What are you using to power the converter?
@@KonaBlueSVT i bought an 120ac to 18 volt dc power converter plug like you showed in the video. it seems to be charging slowly. the power output is 4 volts at .5 amps when i test it. when i test the light is solid red. put on the battery in the correct locations and it blinks red
I have not experienced the flashing red light. Make sure your power input is not more than 8 amps. If that's not the problem and the unit is still outputting power, then I would question the buck converter itself, maybe it has an issue. These things are pretty cheaply built.
@@KonaBlueSVT i think the problem may have been, that i put the clips on first and then plugged it in. i unhooked it and turned up the amperage to 1 amp and clipped back onto the battery and it seems to be working normal now. solid red and charging. it was still charging before but it was very slow. i think when the light is flashing it puts out intermittent power in 1 second bursts when the light is on. so takes twice as long. i went from 3.5 volts on one cell to like 3.8 volts in like 7 hours
Glad you got it working!
Did it do the same thing next time you drained it down?
No, it has been working normally since then.
@@KonaBlueSVT Nice.. Ill try this on my next one.. I usually just take them to work and trade them. Shhhhh lol
@@chipsammich2078 Haha, You will see them completely die sometimes, but I have had pretty good luck bringing them back using this method.
This is not a permanent fix but only temporary
Because of this battery issue I have already switched to dewalt flexvolt
I am waiting for the day this one quits, but we are over 4 months and it is still working good!
i checked all cells and they are all at 4 v but still flashes when put in charger
Likely has a short or bad circuit then
Dude I switch from makita and I regret getting rid of my makita tools I still like Milwaukee but really disappointed because 5 high output batteries do this non of my 5amps do this my makita never did that
That's a bummer! Luckily, I've only had it on 1.
You can't test amperage this way, doesn't work. You left the clips connected to your terminals the same way for testing voltage out of the buck charger? There's something missing to get amperage reading like you're doing
You check amperage and voltage the same way, you just change your meter settings?
@KonaBlueSVT at least with Klein, it won't read a steady current out of the buck charger, but it also pulses. That's what's making be believe the power supply is not true DC but I went through a number of them connecting the outputs to the meter, not through the buck charger, and they're all blasting nothing then flare to 1.3 amps and back down? 🤔 I can't find anything testing current this way though, usually you have to have a load and I guess the multimeter is not enough?
Do you have a 2nd meter to check it? Have you checked your meter fuse?
@KonaBlueSVT I put the meter in line with the battery connected and got a reading like you show, kept it at 1A and seems to be charging. I haven't found a meter that would measure current directly out from the buck charger, not sure how you're doing that or I'm missing something in the video, that would only work for voltage.
Unless your buck charger puts that led in the output circuit, but mine doesn't, and you can't check current using the output leads from the buck charger alone from what I can tell.
and you have to build your own charger to fix the battery, don't you have a simple way to fix it?
How about discharging the high charged cells?
Any adjustable battery charger will work. If you discharge them down to match, the circuitry will prevent all of them from charging.
Milwaukee tools are great but the design of their battery packs are too complicated. Milwaukee puts the BMS inside the pack. DeWalt puts all the BMS in the charger making the pack less complex.
everyone but dewalt puts it in the battery. thats how all batteries work, they need a bms.
@@LamoidZombieDog You only need a BMS when charging. A voltage cutoff is all you need during discharge and that’s onboard. DeWalt batteries last much longer than “everyone else” because of this.
@@yolo_burrito no, DeWalt batteries do not have a voltage cutoff. This is why you have to be very careful when using them with an adapter for other tools, because they will not cut off and will undervolt. The chargers won't charge the batteries either because the voltage is so low they can't detect it (like m M12 battery at 0.5v output) or they are so discharged it's not smart enough to safely bring it back to normal voltage.
I've got a ton of Milwaukee tools and batteries. I have to say, their batteries are shit. I've had no problems with my Dewalt packs, but the Red ones are always giving this sort of problem. I'm looking at one right now that won't charge past 2 bars. Milwaukee sucks.
-- And I'm not about to go through this process.
Agreed. I have Milwaukee, Dewalt, and Makita. No more Milwaukee for me. This is ridiculous. They say their warranty is 3 years on batteries. They should have made an exception.
Incells I knew Milwaukee wasn’t getting no play
Milwaukee batteries are trash, I lost 2 of these already. I'm ghoing to buy the off brand version to replace them.
This is way to complex lmao. They can just send me a new damn battery
If it's in warranty.....