My cordless drill won't charge, any ideas?

Hey everyone, new here. I've got a DeWalt 20V max drill, and the battery won't charge. I plug it in, the light on the charger blinks red, but no charging. I've tried different outlets, no luck. Anyone had this issue? Think it's the battery or the charger?

Had this happen to me last year. It's usually the battery contacts. Try cleaning them with a pencil eraser or some rubbing alcohol. If that doesn't work, could be a dead cell in the battery pack. Check if the charger works with another battery if you have one. If the charger is fine, it's probably time for a new battery. I got a knock-off on Amazon for half the price and it's been working fine.

Before you go the cheap route, check the battery voltage with a multimeter. If it's below a certain threshold, the charger won't recognize it. Sometimes you can 'jumpstart' a dead battery by putting it in parallel with a good one for a few seconds. I've done that with my 18V NiCd packs, works like a charm. But be careful, don't overdo it. Also, make sure the charger is the correct one for the battery chemistry. Li-ion charging is different from NiCd.

True, but honestly, if it's an old battery, might just be cheaper to replace. I've had good luck with aftermarket batteries, they're like half the price. Just make sure the specs match. Also, don't leave the battery on the charger too long, that can kill it too.

Thanks guys. I'll try cleaning the contacts first, and if that fails, I'll check the voltage. I don't have a multimeter but I can borrow one. If it's the battery, I'll look into replacements. Appreciate the help!