u/rofl1337waffle

Found this circle on a battery after taking a look underneath because it’s not holding a charge. It’s kind of old at this point and hasn’t been used in over a year, but my friend wanted to try and get a file off of it and it’s been running really slow. I couldn’t find any information on something that looked like this, and the rest of the battery isn’t inflated, but I wanna double check and make sure just in case.