Milwaukee M18 dead battery

[julianf]

Just come to use my drill, which i use fairly frequently, and nothing - battery flashes error codes on charger.

Its not had heavy use at all, just died. Just out of warranty, of course.

It would have had a reasonable state of charge, so not left empty or anything.


Are there any tricks to "reboot" items like this? I mean if the BMS has failed, then its stuffed, but, if, somehow, one of the cells has got below threshold, and the BMS has declared the unit a write off, id probably like to do some meddling.

Any ideas?

 

[Kram]

Yes, first thing is check voltage of the pack, what does it read? Then open it up and check voltages on each cell.
Ideally disconnect the cell pack from the pcb and try it on a RC balance charger to rule out the BMS.

 

[J1nx]

Contact Milwaulkee, I know Makita often replace faulty batteries even out of warranty. After that I’d open it up as above and check individually the cell voltages.

 

[ChrisBailey]

I think the battery shutsdown entirely if the voltage drops below a certain value.
People get this problem when buying new M18 batteries that have been sitting on the shelf a while.
I think you can forcibly charge the batteries by putting some volts on the cells.
The balance charger that comes with the tool just gives up when it sees an error code.

Once youve got the cells above the shutdown voltage, the normal charger will work again.

 

[Munkul]

My cousin used to use M18 batteries heavily on his vacuum cleaner and car polisher and kill them, he revived them by "jumpstarting" them with a 12v car battery charger for 10 seconds and quickly putting them onto the proper charger.

 

[Craig-SM]

 

[500e]

We used to get it a lot on hire radios they could switch them on but never off posted back . could be a week switched on , jump start worked oh 90% of them

 

[gordon stephenson]

I jumped a couple of Milwaukee batteries that the charger indicated faulty, Just a couple of wires from a PP9 battery to the two outside contacts On the Milwaukee battery for a few seconds, then the Milwaukee charger charged them normally, really easy,

 

[Turbo]

On the Makita LXT 18v batteries if you get the error lights 3 times when trying to charge them the bms shuts down & will not work again, effectively rendering the battery as scrap! This happened to a battery at our Men's Shed, luckily I spotted it the first time it happened before somebody else tried to charge it. I took it home & used my Imax B6 rc charger to do a balanced slow discharge & recharge and it's now charging fine on the Makita charger.

So I'd advise looking into this before trying to charge your Milwaukee again!

 

[Munkul]

On the Makita LXT 18v batteries if you get the error lights 3 times when trying to charge them the bms shuts down & will not work again, effectively rendering the battery as scrap!

I buy the cheap ebay BMS boards and fit them to bricked batteries, they seem to work just fine for years after

 

[knighty]

Milwaukee batteries are screwed together, you can take them apart without damaging them

then check the voltage of each pair of cells, check if there's a dead one


I had a dead cell, tried to force charge it a bit from a bench top power supply but it just go thot :-(



I somehow lost all my ryobi chargers (must have half a dozen of them) - tried to charge one from a power supply but they won't take a charge unless connected to a charger - there's a 3rd contact on them, (+ve -ve and 3rd one)

can't take them apart to investigate so plugged it into a drill with wires jammed in to join to the power supply.... and it wouldn't take charge unless the drill was in use, their must be some specific on/off system for that 3rd contact controlled by the chargers/drill - not a simple "it's plugged in" system

left a cable tie pulling the trigger very gently so could push some charge into it..... then found a charger 2min later :-o

 

[julianf]

Milwaukee batteries are screwed together, you can take them apart without damaging them

...only if you can find a "security" torx key

(of course, i can find all the others in the set, but that one got damaged, and i never got around to making the "halfords advanced" claim)

 

[123hotchef]

one of mine would not charge on one charger but it did on another weird. it was a m12 battery though

 

[anto44]

I've had problems with m12 batteries not charging and showing as faulty.
Getting a pick and bending out these 3 contacts so they make a better connection cured it.

 

[123hotchef]

i just had a play with my dodgy battery m12
it shows 1 bar on the tool
put it into the charge it is red and charging but after a ew minutes it shows fully charged
put it back into the tool and it goes flat or back to 1 bar in 0 seconds to a minute of using the tool

 

[julianf]

just got the multimeter on it - battery is showing 17.6v

my good battery, direct from charge, is showing 20.somthing

17.6 doesnt seem that low?

 

[julianf]

Ok, so i "jumped" it up to 18.somthing volts, and stuck it on the charger, and its still flashing error.

When jumping i pressed the "state of charge" button, and that still didnt even light, even though the cell voltage was 18 ish - the other battery (the good one) showed about half charge when on jump.

So, my suspicion is that the cells are fine but the electronics are stuffed.

I buy the cheap ebay BMS boards and fit them to bricked batteries, they seem to work just fine for years after

Can you tell me more? That sounds like it may be what i need?

edit:

Im guessing this -

For Milwaukee 18V M18 Li-Ion Battery Case PCB Charging Protection 9Ah Sticker # | eBay

Find many great new & used options and get the best deals for For Milwaukee 18V M18 Li-Ion Battery Case PCB Charging Protection 9Ah Sticker # at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

but at £15 plus tax, plus parcefarce processing fee, im probably £35 toward a new battery!

 

[julianf]

For Milwaukee &M18 18V PCB Board Electric Power Tool Replacement Lithium Battery Protection Circuit Board - AliExpress 44

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

£8.50 plus tax (no processing) is a bit better gamble

still need to find that security torx though!

 

[123hotchef]

Ok, so i "jumped" it up to 18.somthing volts, and stuck it on the charger, and its still flashing error.

When jumping i pressed the "state of charge" button, and that still didnt even light, even though the cell voltage was 18 ish - the other battery (the good one) showed about half charge when on jump.

So, my suspicion is that the cells are fine but the electronics are stuffed.



Can you tell me more? That sounds like it may be what i need?

edit:

Im guessing this -

For Milwaukee 18V M18 Li-Ion Battery Case PCB Charging Protection 9Ah Sticker # | eBay

Find many great new & used options and get the best deals for For Milwaukee 18V M18 Li-Ion Battery Case PCB Charging Protection 9Ah Sticker # at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

but at £15 plus tax, plus parcefarce processing fee, im probably £35 toward a new battery!

what battery is it? size and model

 

[J1nx]

If it’s a cell out of balance then the ‘jumpstarting’ wont achieve much. Tbh it’s not a great idea anyway, the protection is there for a reason, should you get it working I’d take precautions such as charging in an outbuilding and away from anything combustible. I know that sounds a bit Safety Simon, but a li-ion pack can cause some damage.