I helped my neighbor take down a wooden fence with my older 18V circular saw. I used a cheap 18V-20V adapter without realizing it didn't have a low voltage cutoff feature like the official ones do. It drained my 5AH battery all the way down to 7 volts, which is way too low. Jumping with another good battery isn't working, and the charger shows a steady red light indicating it's not charging. The battery is older, so it's out of warranty. I'm curious if there's any way to charge it using alternative methods like a lipo charger. Any advice on whether the battery can be saved?
2 Answers
Seven volts is definitely not good news. It sounds like the battery has been seriously damaged, and trying to pump unregulated current into it could make things worse. I’d recommend just disposing of it safely to avoid any fire hazards. Better to be safe than sorry!
Did you not notice the saw losing power? They drop off significantly when they get to around 15 volts; 7 volts is basically dead!
Advice taken! I put it out on the patio for the night and won’t bother opening it up. It really stinks to ruin a perfectly good battery. It makes me wonder why they even sell these knockoff adapters that can drain batteries so dangerously low. I started an Amazon return for the knockoff and bought 2 legit Dewalt ones, but man, they’re not cheap!