Driver won't charge - is it the battery or the tool?

Hey all, my 18V cordless driver stopped charging yesterday. I plug it in and the charger light stays red, never turns green. Tried a different battery and it charges fine, so it's the battery. But this battery is only 6 months old! Any ideas? Should I just buy a new one or is there something I can try?

Had this happen to me with a DeWalt battery. Turned out some of the contacts were just dirty. Clean them with a pencil eraser or some contact cleaner and try again. Worked for me. Also, make sure the battery isn't too hot or cold - sometimes they won't charge if temp is off.

Good point Sam. Also, check if there's any corrosion on the contacts. If it's still under warranty, you might get a free replacement. But if not, might be a bad cell in the pack. I've seen some guys rebuild them, but for a 18V, it's often cheaper to just replace. Make sure it's an original or good aftermarket.

I had a similar issue with a Makita battery. It was a faulty cell causing the charger to not detect it. I had a buddy who does electronics, he replaced the cell and it was good as new. But if you're not handy with that, just get a new one. Also, check that your charger is compatible with the battery - some chargers won't charge certain types.

Thanks, guys! I'll try cleaning the contacts first, and if that doesn't work, I'll check the warranty. Probably just gonna grab a new battery this weekend, better safe than sorry. Appreciate the help!