I have boughten a rechargeable battery and a charger a few months ago and when I received it, I briefly hooked it up to a multimeter and shoved it in the back of a drawer to use on another project that I was planning to do a couple days later, but it didn't work out, and I kinda forgot about it.
Fast forward a few months. Today, I checked it again, and then I wanted to see if it would fit inside a small space with a wire. It fit perfectly without the wire, but I had to force it a little to get it into the case. When I pulled it out, I noticed that there were some weird "bumps" running along the long way of the battery, but not perfectly straight. I never looked it that closely, but I would assume I would notice it.
That isn't my question. I don't know if it was manufactured that way, it was damaged during shipping, or if I did it. It is a little late to contact the seller, my fault, of course. Is this just a cosmetic flaw that I don't have to worry about? (I found a different use for the battery, so it's not going to be crammed in there anymore.) Should I buy a new one? Test it? It's kinda weird, and it seems cosmetic (no leaks… yet), but I am reluctant to charge it or use it unless I know it's okay and safe.
Photos:
I don't mind replacing them if necessary, but I want to get this done without waiting for a part to come if I can.
They are AAs; "GTL Li-ion 14500 1200mAh 3.7v."
Best Answer
In my experience, the best way to check if a battery is damaged is to hook it up to a multimeter and check the output voltage (if it's fully charged). It should be safe to charge and test unless it is leaking fluid. It's always a good idea to keep an eye on them while they are charging, especially if you think they may be damaged.