Drill battery not charging - is it toast or can I fix it?

So my trusty 18V drill battery just stopped charging. It's a few years old, but worked fine until yesterday. Plugged it in, charger light stays red, no green. Tried a different outlet, no luck. Is it dead dead, or can I bring it back to life? Don't want to spend $80 on a new one if I can help it.

Before you toss it, check the contacts on both the battery and the charger. Sometimes they just get dirty or corroded. Clean them with a bit of rubbing alcohol and a q-tip. Also, if the battery has a low voltage, the charger might refuse to charge it. You can try a "jump start" by connecting it to a good battery for a few seconds (carefully, with correct polarity) to get it above the threshold. I've saved a few that way. But if it's really old, it might just be time to replace it. Look for aftermarket ones on Amazon - way cheaper.

Yeah, what Felix said! Also, some chargers have a reset function - unplug the charger and let it sit for 10 minutes, then try again. And if you have a multimeter, check the voltage of the battery. If it reads less than like 14V for an 18V battery, it's below the charger's detection. I've revived a few with a 12V car battery charger for a few minutes. just don't overdo it. But honestly, if it's more than 3 years old, those lithium cells are probably worn out. I'd say it's a good excuse to upgrade to a brushless drill - they're way more powerful and batteries last longer!

I've brought back a few old NiCad batteries, but if it's Li-ion, they have a protection circuit that can shut down permanently if one cell goes bad. Sometimes you can open the case and check the cells - if one is swollen or reading 0V, that's your problem. You might be able to replace that cell, but it's a bit of a hassle. For most folks, it's not worth it. Try the simple tricks first, but be prepared to buy a new one. I'd also check if there's a recall or warranty claim - some brands have good warranties. And if you do get a new battery, make sure it's the real deal from a reputable source, not a cheap knockoff that might catch fire. Just my 2 cents.

You guys and your aftermarket junk... Look, I only trust OEM batteries. I had a cheap one swell up and almost ruin my drill. If it's a DeWalt, just go to Home Depot and get a genuine battery. Yeah, it's pricey, but you can't beat the peace of mind. And honestly, a drill is only as good as its battery. $80 is a small price for a reliable tool. But before you buy, check if the charger itself is the problem - they can fail too. I've seen chargers die more often than batteries. If you have a friend with the same brand, swap chargers and see. But never mix brands, you'll blow something up. Trust me, I'm a pro.