Battery Not Charging? Let's Diagnose!

Hey everyone, I've got a problem with my cordless mower. It's a few years old, and now when I plug the battery in, the charger just blinks red and green and never starts charging. I've cleaned the contacts, but no luck. Any ideas?

Hey Gary, red/green blinking usually means a connection issue or a dead cell. Have you checked the voltage with a multimeter? If it's too low, the charger won't recognize it. Sometimes you can 'jump-start' it by putting it in parallel with a good battery for a few seconds, but careful—do that at your own risk!

Pete's on the right track. In my experience, blinking often indicates one faulty cell. You can open the pack and measure each cell's voltage. A lot of times it's just one bad cell. You might need to replace the whole pack, though. Also, make sure the charger matches the battery voltage—I've seen folks mix up 18V and 20V.

Yeah, what they said. But before you go tearing it apart, check the charger itself. Try charging a known good battery if you have one. Could be the charger that's toast. I had one that used to blink like a disco until I replaced the charger. And if you do open it, watch out for the BMS—some of those circuits don't like being messed with.

Thanks guys, I'll try the multimeter first and see if I can borrow a charger. I'm not too keen on tearing it open, but if the voltage is low, I might give the jump-start a try. Any tips on how to do that safely?