Dewalt 20V grinder not charging - anyone else had this?

Hey guys, my DeWalt 20V max grinder (DCG413B) just stopped charging. It was working fine yesterday, plugged it in today and the charger just blinks red. Tried a different battery, same thing. Any ideas before I toss it in the trash?

Could be the charger itself, not the grinder. Have you tried cleaning the contacts? Sometimes dust and grime mess with the connection. Also, check if the charger has a fan running - if not, it might be dead.

I've had this issue with a few DeWalt chargers. Could be the battery is too hot or too cold. Let them sit for a while at room temp. Also, check if the batteries are still under warranty - DeWalt replaced two of mine for free.

Tried cleaning contacts and letting batteries cool down - no dice. The charger fan spins, so maybe it's the batteries? Both batteries are about 2 years old. Guess I'll call Dewalt. Thanks for the help!

Before you call, try pushing the battery in harder. I know it sounds stupid, but sometimes the latch doesn't fully engage. Also, check for any swollen batteries - if they're puffy, stop using them immediately.