Dewalt drill battery not charging – blinking red light

Hey everyone, my Dewalt 20V max drill battery just stopped charging. When I put it on the charger, it blinks red. I've had it for about 2 years. Any idea what's wrong? I'm hoping it's not dead for good. Thanks!

Blinking red usually means the pack is too hot or cold, or it's a bad cell. Let it cool down for a bit and try again. If it still blinks, try another charger if you have one. If not, check the contacts for corrosion or dirt. Sometimes you can clean them with a pencil eraser. Also, if you have a multimeter, check the voltage at the terminals – should be around 20V. If it's way low, one or more cells are shot. I've rebuilt packs before, but it's tricky. Might just get a new one.

Don't give up on it yet! I had a similar issue with my 18V drill battery. Ended up being a broken wire inside the pack. If you're comfortable opening it up, you might see a loose connection. But careful with the lithium cells – they are dangerous if punctured. Also, make sure the charger is plugged into a live outlet and the contacts on the battery are clean. Sometimes it's just a bad connection. If you have another Dewalt battery, does it charge? If not, it's the charger.

Thanks for the tips! I checked with another battery and it charges fine, so it's the battery. Tried cooling it, no luck. Cleaned contacts, still blinking. Guess I'll have to open it up or just replace it. I use this drill a lot, so probably just buy a new one. Appreciate the help!