Could use some expertise with troubleshooting an m18 battery.

Thread Starter


Joined Oct 9, 2023
Hey ,so battery had worked fine though was a bit dirty and being in a hurry (plus had wire brush in my hand already... reflexive ) before puttin it on the charger my hand proceeded to use wire brush to clean the terminals... of course felt stupid instantly though after self forgiveness and hours of google/youtube research, i cant find any similar situations...
So i used multimeter to check each cell individually.. all are alive from what i can see but the charger blinks red and green and wont charge it.. obviously i shorted somthing though was low juice so dont think its too major.. only visual hotspot that has me thinking is in these photos it looks like a microchip or 555 type thing that has a crater in it. Any help as too possible repairs and or chip substitutes for circuit repair and or clarification on where why how it mightve fried in that spot woulf be greatly appreciated!!! Thankyou



Joined Jan 27, 2019
Welcome to AAC.

The component with the crater is toast. It is hard to say what it is but at a guess it is a multi-MOSFET package df some sort. Sadly, it is it appears unmarked, but that could be an artifact of the blurry photos.

Can you read any markings on it? You can try putting something chalky on it then wiping it off which may expose light laser etching. Failing finding a part number your best bet is to find a pack that failed due to dead cells or some other cause that doesn’t involve that chip and swapping.