Help! My DeWalt string trimmer battery won't charge - flashing red light

Hey everyone, hoping someone can help me out here. I've got a DeWalt 20V Max string trimmer (model DCMWSP220T1) that I bought about 8 months ago. Yesterday I went to use it and the battery was dead, no problem - threw it on the charger. But now the charger just shows a flashing red light and won't charge at all. Tried a different outlet, same thing. The battery itself doesn't feel hot or anything. Anyone run into this before? Really don't want to buy a new battery already!

Classic DeWalt issue man, their batteries are overpriced and fail way too soon. I had the same thing happen with my Ryobi trimmer last year. Before you drop $100 on a new DeWalt battery, try this: clean the contacts on both the battery and charger with some rubbing alcohol and a q-tip. Sometimes dirt or corrosion builds up and causes bad connection. Also check if the battery has any physical damage - dropped it recently? If cleaning doesn't work, you can sometimes revive these by jumping it with another battery for a few seconds (look up YouTube tutorials). Or just buy a cheap aftermarket battery on Amazon - half the price and works just as well IMO.

Tim, stop recommending off-brand junk that'll burn someone's house down. Dan - first, check if your battery is still under warranty (DeWalt has 3-year on tools, 2-year on batteries). Call their customer service, they're actually really good about replacements. Second - have you tried a different DeWalt battery on that charger? Or that battery on a different DeWalt charger? Need to isolate whether it's the battery or charger. The flashing red usually means charging fault - could be battery protection circuit tripped. Sometimes letting it sit for 24 hours off everything resets it. But seriously, stick with OEM parts - I've been running DeWalt on my crew for 15 years and their support is worth the premium.

Thanks guys! Tim - I did try cleaning the contacts, no luck there. Battery looks fine, no drops that I remember. Carl - good call on the warranty, I'll check my receipt. I don't have another DeWalt battery to test (this is my only 20V tool so far). The charger works fine with my drill battery though, so seems like it's the trimmer battery. Let it sit overnight like you said, still flashing red this morning. Guess I'm calling DeWalt today. Will update what they say!

Let us know what DeWalt says, but I'm betting they'll charge you shipping at minimum. My Ryobi battery died after 14 months (just out of 1-year warranty) and they wanted $65 for replacement. Got a knockoff for $28 on Amazon that's been going strong 2 years now. Sometimes brand loyalty just costs you money. Good luck though!