I had the same problem with my M12 charger. It started after I drained a battery to nothing. My documentation says if both the Red and Green lights on the charger are flashing simultaneously there is a problem with the battery. But after plugging it into the charger for just a short period of time the charger went dead (no lights) and it wouldn't charge anything. So I took the cover off and took some voltage measurements while looking for a blown fuse. All the fuses checked good. While checking I noticed there were 4 test points on the circuit board. So I removed power and lightly pressed on it it with with the common reset tool (paper clip). Inserted the dead battery and immediately got a good red light indicating that it was charging. Didn't take long and the battery was fully charged. Hopefully it will be okay when I need to use it again.
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Problems with Milwaukee M12 Charger(S)
- Thread starter Tom4693
- Start date
KnurledNut
Well-known member
This is good info. Thanks for taking time to share the details and provide a picture. Welcome to the board.
Out of curiosity, did the reset click when you pressed it, like a button that had been tripped?
Out of curiosity, did the reset click when you pressed it, like a button that had been tripped?
dnschmidt
Well-known member
I've throw away at least five of the M12 chargers that were brand new that came with kits. I have a bank of rapid chargers that do both M12 and M18 so the M12 were useless to me.
Rusted Nut
Well-known member
Welcome!
If the battery is too cold or too hot, as maybe in your case since you ran dead; the red and green lights will flash until battery is the correct temp for charging.
If the battery is too cold or too hot, as maybe in your case since you ran dead; the red and green lights will flash until battery is the correct temp for charging.
Mike S.
Well-known member
I'll have to try this out. My M12/M18 combo charger hasn't charged my M12 batteries in over a year. I had to buy a separate standalone M12 charger. It would be nice if I could get the combo charger working again.