Help! My circular saw battery won't charge after a drop

Hey all, I'm pretty new to the whole power tool scene. I've got a cordless circular saw (18V Ryobi) and I accidentally dropped it onto a concrete floor the other day. Now the battery won't charge - it still fits into the saw and the light on the charger doesn't even blink. I've tried cleaning the contacts with a pencil eraser and checking the charger with another battery (which works fine). Any ideas what could be broken? Is it worth opening up the battery, or should I just buy a replacement?

Honestly, if you dropped it and now it won't charge, it could be a cracked solder joint inside the battery pack. The drop might have knocked something loose. I've resurrected a few packs by opening them up and re-soldering the connections. But if you're not comfortable doing that, replacement is safer. Also check if the battery is swollen or damaged - if it's swollen, don't mess with it, just recycle it. Good luck!

I've seen this happen more times than I can count on job sites. Usually it's the battery's own protection circuit tripping from the impact. Sometimes you can reset it by leaving it in the charger for a minute then pulling it out and putting it back. But if that doesn't work, and the battery is not swollen, I'd try opening it up (carefully!) and checking the BMS board for loose wires or a cracked trace. If you can't fix it, just replace it - a new battery is cheaper than a new saw. Also, always keep an eye on those contacts, a slight bend can cause charging issues.

Thanks, guys! I'll try the charger reset trick tonight. If that fails, I'll probably take the battery apart (I've watched some youtube videos). But I'm still a bit worried about messing with lithium batteries. Any tips for safely opening it? And how do I know if it's swollen if it's inside the case?

To check for swelling, look at the seams of the battery case - if they're starting to separate or the case feels puffy, that's a bad sign. Also, if it's noticeably heavier than a similar battery, that could indicate swelling inside. When opening, use a plastic pry tool and be careful not to puncture the cells. Only work on a non-flammable surface, have a fire extinguisher nearby, and don't use metal tools that could short the terminals. If you see any damage to the cells, stop and recycle. Good luck, and let us know how it goes!