why my battery auto increase after plug out the charger

It may indicate the battery has a hardware failure. Unfortunately it probably won't be detected by the Apple Diagnostics, but it never hurts to check anyway. Also, keep an eye on the Battery Condition reported by macOS. If you see the battery condition change to "Service Recommended", then it confirms a hardware problem in this case (not necessarily in other cases). I'm not sure how often macOS actually updates the battery condition status...I know it is not very often. Also, try running the Apple Diagnostics when the battery is around 90% charge since you discovered the issue at that charge level (you may need to let the battery charge level drop to 90% before you boot the diagnostics, then connect the power adapter just before agreeing to the diagnostic's EULA so that the test may actually test the battery at the 91% point). You may also want to try running the diagnostics when the battery is at other charge levels such as 80%, 50%, 20%, or even 5%. I know from personal experience battery issues usually are more likely to be detected at low charge levels, but even the simple act of connecting the power adapter is enough to hide the battery issue although the power adapter needs to be connected to prevent a missing power adapter from causing a diagnostic error code.

FYI, I have seen this occur a few times while supporting my organization's Apple laptops. If it only increased by 1-2%, then it may be Ok and ignored for the moment. However, a 9% increase is much more significant and indicates at least one of the battery cells is beginning to fail.

krshivam wrote:

how to check?

It depends whether it is an Intel Mac or an M-series Mac. With the M-series Mac it required me to create a custom shell script to gather the information since the built-in macOS command line utility that works on an Intel Mac is partially broken on the M-series Macs.