Grinder battery not charging? Need help!

Hey all, I'm having trouble with my cordless angle grinder. I've left it on the charger overnight and the battery light is still red. It worked fine last week. Any ideas? It's a 4.5" DeWalt, about a year old.

Have you checked the charger itself? Sometimes the contacts get dirty or the charger is just done. Also, try resetting the battery by pressing the power button for 10 seconds. If that doesn't work, it might be a dead cell. How often do you use it?

Yeah, I had the same issue with my Makita. Turned out the battery was just too hot from sitting in the sun. Let it cool down and try again. Also, make sure the charger is plugged into a surge protector, not a dimmer switch. Those can cause issues.

Before you buy a new battery, check if the charger has a warranty. Some brands replace them free. But if it's the battery, have you tried another one? It's possible the grinder is pulling too much current. My old one did that, it was the brushes going.

Thanks for the suggestions! I'll try the reset and cool-down. If not, I'll test with a spare battery from my drill. The charger is maybe a year old too, so might be under warranty. I'll post an update.