Milwaukee M18 battery won't fully charge

[Fodeman]

I've got this M12/M18 combo Milwaukee charger that works fine on all of my M12 & M18 batteries except for one M18 XC 5.0.
The charge indicator light toggles between green/red soon after plugging the battery in. The light on the battery only shows 3 bars, which, to me, would indicate a cell going bad.
Has anyone had the same problem with their's? If so, what did you do to repair?
I bought the battery in factory packaging on Ebay. The seller sent me another, no questions asked and didn't have to return the old one. The replacement works fine. I'm just trying to salvage this "freebie" to charge completely.

 

[sparky 1971]

I've had the green-red flash on a few batteries but never paid attentionto the charge level indicator since it was dead. A couple of times I was able to reinstall the battery and push it down a little harder. All of the other times I tossed the battery in the trash when method #1 was unsuccessful.

 

[Fodeman]

Yes, I'm with you about it being firmly seated in the charger, as well as giving the battery a firm slap on the bottom when plugging it into, say, a drill.
If nothing else, if I take this one anywhere besides the home ground, I'll be sure and have a spare also.

 

[cgrutt]

Bad cell. Prob Samsung 18650 25R but open pack up and confirm.

 

[Sumboodie]

I've had a couple that only worked on certain chargers.

Need a charger? I have like 4 or 5 of them.

 

[dnschmidt]

That's Milwaukee's way of telling you you've got a bad cell in the battery. Time to throw it out. HD has a recycle bin that I put mine into.

 

[Fodeman]

Bad cell. Prob Samsung 18650 25R but open pack up and confirm.

Appreciate it, but I'll just keep recharging (it will still hold a charge) until it's completely dead. It's not worth my time to isolate the bad cell.

 

[Fodeman]

I've had a couple that only worked on certain chargers.

Need a charger? I have like 4 or 5 of them.

Appreciate it, but I'm good with my charger.

 

[Fodeman]

That's Milwaukee's way of telling you you've got a bad cell in the battery. Time to throw it out. HD has a recycle bin that I put mine into.

Good to know about HD. Thanks

 

[cgrutt]

Appreciate it, but I'll just keep recharging (it will still hold a charge) until it's completely dead. It's not worth my time to isolate the bad cell.

I'd keep an eye on it while charging as these are Lithium cells and can pose a fire risk... I wouldn't leave unattended if you're having problems with pack but charging anyway. Pack comes apart with a few screws and you can visually check cells for damage. Good luck.

I have an M18 pack with a bad cell that I've been meaning to replace I try to post a pic later bad cell looks corroded and has significantly lower voltage than other cells. Pack won't charge though just gets alternating green/red warning on charger.

 

[Fodeman]

I'd keep an eye on it while charging as these are Lithium cells and can pose a fire risk... I wouldn't leave unattended if you're having problems with pack but charging anyway. Pack comes apart with a few screws and you can visually check cells for damage. Good luck.

I have an M18 pack with a bad cell that I've been meaning to replace I try to post a pic later bad cell looks corroded and has significantly lower voltage than other cells. Pack won't charge though just gets alternating green/red warning on charger.

A couple of hours ago, I removed the 4 screws with a T10 security bit and there weren't any obvious signs of corrosion or overheating. I'll have to youtube how to check each cell. Even though I'm a retired electrician, it might not be something I want to get too involved in.

 

[captain14]

Maybe for peace of mind get a simple mechanical timer to run the charger for a designated amount of time.

 

[cgrutt]

The M18 battery packs usually have one or more sets of five 18650 cells connected in series. The 5-cells in series provide the nominal 18v. There is one set on the lower amp packs and two, three or four sets connected in parallel for higher amp-hour packs. Each cell has a nominal voltage of 3.6 or 3.7v but can vary between about 3.0v and 4.2v depending on charge status. You can test voltage of each cell with a voltmeter set on DC-volts. A bad cell will typically measure significantly different than the good cells. Say 1.5v when other cells are reading 3.5v. Easy to check if you have a volt meter.

 

[cgrutt]

BTW this is the pack I'm having problem with you can see the bad cell, second from bottom.



These are the replacement cells.



I bought a small arc welder to repair pack but haven't used it yet.

 

[Fodeman]

BTW this is the pack I'm having problem with you can see the bad cell, second from bottom.



These are the replacement cells.



I bought a small arc welder to repair pack but haven't used it yet.

Thanks for the info. Since these batteries supposedly have a 3 year warranty, I'll try calling 800-SAWDUST first to see if they'll replace it. It's less than a year old. Only problem is, I don't have a receipt, unless they can research a serial number.
I've got a XC 5.0, which has 2 sets of 5 cells. Did you get enough cells to replace them all in yours?

 

[DerekV]

BTW this is the pack I'm having problem with you can see the bad cell, second from bottom.



These are the replacement cells.



I bought a small arc welder to repair pack but haven't used it yet.

I hope you’re not planning on putting those 25Rs in a pack full of 20Rs

 

[cgrutt]

Thanks for the info. Since these batteries supposedly have a 3 year warranty, I'll try calling 800-SAWDUST first to see if they'll replace it. It's less than a year old. Only problem is, I don't have a receipt, unless they can research a serial number.
I've got a XC 5.0, which has 2 sets of 5 cells. Did you get enough cells to replace them all in yours?

Yeah I'm going to replace all of them and bought spares for other packs. I've read about people salvaging these from recycling drop offs etc and using good cells to repair other packs but the new batteries were fairly inexpensive so will just replace all of them when time comes.

 

[ATC]

I just had to warranty a 8.0 battery that was having similar symptoms. Put it on the charger, and it would show a green light as charged. Take it off and push the button, and only one bar would light up.

 

[Fodeman]

I just had to warranty a 8.0 battery that was having similar symptoms. Put it on the charger, and it would show a green light as charged. Take it off and push the button, and only one bar would light up.

Thanks, I'm going to try the warranty route as well.

 

[Fodeman]

Yeah I'm going to replace all of them and bought spares for other packs. I've read about people salvaging these from recycling drop offs etc and using good cells to repair other packs but the new batteries were fairly inexpensive so will just replace all of them when time comes.

Thanks

 

[cgrutt]

I hope you’re not planning on putting those 25Rs in a pack full of 20Rs

I'm replacing all of them.

 

[Sweetcorn]

Thanks for the info. Since these batteries supposedly have a 3 year warranty, I'll try calling 800-SAWDUST first to see if they'll replace it. It's less than a year old. Only problem is, I don't have a receipt, unless they can research a serial number.
I've got a XC 5.0, which has 2 sets of 5 cells. Did you get enough cells to replace them all in yours?

You can Google "Milwaukee m18 date code"
and tell pretty quickly without having to call.

Here, I just Googled it:

The date code can be found stamped on the top of the battery housing. The first four digits are the year and week of production, respectively. So in this example of "150708G", this battery was made on late February of 2015

 

[Fodeman]

You can Google "Milwaukee m18 date code"
and tell pretty quickly without having to call.

Here, I just Googled it:

The date code can be found stamped on the top of the battery housing. The first four digits are the year and week of production, respectively. So in this example of "150708G", this battery was made on late February of 2015

Great! Thanks for the info.

 

[darkzero]

I wouldn't just get rid of them immediately. If you're lucky it may just be a bank of more of cells that are unbalanced. That happened to me last year, rebalanced them & they have been working fine since. A coulpe of them are from 2015 also. Yes cells do go bad but it's not uncommon for a bank of cells to get unbalanced in a pack.

https://www.garagejournal.com/forum...tery-not-fully-charging.526906/#post-10482033

 

[Fodeman]

Thanks to all! My battery code is 220125, so it is still under warranty!

 

[Sumboodie]

Good to know about HD. Thanks

I throw mine in the ocean. Helps charge the eels.

 

[dnschmidt]

If it's still under warrantee simply call 1-800-SAWDUST and all will be well.