Battery Not Charging on My DeWalt Impact – Anyone Else?

Hey guys, I've got a DeWalt 20V max impact driver that's been great for years, but now the battery won't charge. It's the original 5Ah battery, and I've tried different outlets and stuff. The charger light just stays red, never turns green. I've cleaned the contacts, but no luck. Any ideas before I drop $100 on a new battery?

Ah man, that's a classic. Have you checked the battery voltage with a multimeter? If it's way low, like below 10V, the charger might not recognize it. Sometimes you can 'jumpstart' it by connecting it to a good battery in parallel for a few seconds (careful though). I've done that to revive a couple old packs. But if it's really dead, you might need a new one.

I've seen this on job sites a lot. DeWalt chargers have a weird design where they won't charge if the battery is too hot or cold. You said you cleaned it, but did you let it sit for a while? Also, check the charger itself. Try another battery on the same charger – if that works, you know it's the battery. If not, charger's toast.

Thanks for the tips. I don't have a multimeter, but I might borrow one. I'll also try the other battery trick. If it doesn't work, I'll probably just buy a new one, but I hate throwing away a battery that might be fixable. Any way to tell if it's the cell that's bad? I've seen people rebuild them, but that seems like a hassle.