My Drill Battery Won't Charge - Is It Toast?

Hey everyone, I've got a 3-year-old Makita 18V drill (the XFD07 model) and the battery just stopped charging. It's the 5Ah battery. When I put it on the charger, the light stays green (indicating full) instead of flashing red or whatever it does when charging. I've tried a different charger and it's the same. Is it dead? Any way to revive it or should I just buy a new one? Thanks!

Sounds like the battery's BMS (battery management system) might have gone into sleep mode or the cells might be unbalanced. I've had some luck reviving a battery by jumping it with another battery - but that's risky. First, try leaving it on the charger for a few hours, sometimes it wakes up. If not, check the voltage with a multimeter. If it's below like 10V, the cells might be too dead to recover. At 3 years, it might just be time for a new one, especially if it's had heavy use. I've got Makita batteries that are 5 years old and still going, but I don't run them to dead too often.

I'm with Mike, but I'll add that if you use your drill daily, 3 years is about the lifespan of a lithium-ion battery, especially if you've been draining it fully. I buy the knockoff brands on Amazon for cheap - they work fine for my crew. But if you want to stick with OEM, check the date code on the battery, might still be under warranty if it's within 3 years from purchase. Makita has a good warranty, so you might get a free replacement. I'd call their support before you toss it.

Before you give up, try the freezer trick. I know it sounds crazy, but sometimes putting a completely dead NiMH battery in the freezer for a few hours can give it a little kick. But for lithium-ion, that's a no-go. Actually, for Li-ion, you might try jumping it with another battery if you're careful - you're essentially giving it a 'boost' to wake up the BMS. I've done it with a few car batteries, but it's risky. The safest bet is to check if there's a reset button on the battery (most don't have one), or you might have to open it up and check the cells individually. But if you're not comfortable with that, just recycle it and buy a new one. The new ones have better cells anyway.

Thanks for the input, everyone! I checked with a multimeter and it shows 5V, so it's really dead. I guess it's time for a new one. Carl, I'll check the warranty - I actually registered it when I bought it, so maybe I can get it replaced. If not, I'll grab a new one - might even get the newer 6Ah for longer runtime. Appreciate the help!