Battery not charging beyond ~50-60%
A few months ago, I replaced by battery (from a third-party seller, not ifixit). It was working great, until recently, when it ran out, then was plugged in overnight and got stuck at 55%. Unplugging it and plugging it back in resulted in it very slowly charging up to 60%. It is stuck at 52% right now. I've tried a SMC reset, I've tried calibrating by fully discharging, and I've tried reseating the connector.
The computer doesn't shut down gracefully when the battery runs out; it always hard powers off around 5-10%. This has been an issue since before I replaced the battery.