Milwaukee M18 Batteries won't charge past 3 bars?

[Matt Meiser]

My 2 original Milwaukee M18 compact batteries are about 4 years old. Recently I've noticed that when I charge them they won't charge past 3 of the 4 bars on the built-in gauge. I'm assuming this means they are wearing out? I tried putting them in the flashlight and running them completely down but it doesn't seem to make a difference.

I also have some of the full size packs that are only slightly newer and all of those seem fine.

[Dan Rude]

I will have to check mine, last time I charged them I didn't have any problem. I do mainly use my M12 and the ext M18's now, but I want to try them on my new brushless impact to see how long they last. Dan

[Matt Meiser]

I tried calling Milwaukee....there's 10 minutes of my life wasted. Pretty much all she was able to tell me is that the compact battery is smaller than than the full size batteries. I was aware...

[Rob Feldner]

I have an M18 drill that is about 4 years old, no hassles with the batteries. In the past I've had success looking for bad cells and replacing them with other batteries, but it can be a bit of a hassle to do.

[Kevin Bourque]

I was told by a battery expert that : You should never let the batteries totally drain down like when you put them in the flashlight. It actually makes the problem worse.

The batteries are just getting old and you will need to replace them.

[Matt Meiser]

I don't think the electronics in these batteries allow them to actually totally drain. When they run out they'll suddenly stop dead and won't work until recharged, unlike old "dumb" batteries of the past.