Hmmm…erratic battery readings…?
Do a thorough visual inspection, preferably with magnification, of the area surrounding the battery connector. There are several tiny SMD components just above the connector. Of particular importance is FL2400, highlighted in red. If it is missing (which can happen when you pry the connector off), then the battery state does not get communicated to the CPU and this can also cause charging issues and fluctuating readings.
[image|1782989]
This is a common error by DIY fixers and inexperienced techs (or even experienced techs not fully concentrated ;>).