10% Battery drain every time I power on Macbook Pro

r.damron wrote:

In the past week or so my battery will loose 10% of its charge immediately on startup, even though it is plugged in, and then will begin recharging to full and hold that charge for the remainder of the day. I'm not doing anything particularly power-hungry in that time, nor do I have any anything charging or drawing power from my laptop, so there is not an excessive demand. From the moment my macbook powers up the percentage slowly ticks down from 100% to 90%, then back up to 100% where it holds without further issue. This only happens on start up (not after sleeping), and there is otherwise no impact on performance.

Any idea what's going on and what can/should be done about it?

About battery health management in Mac notebooks https://support.apple.com/en-us/HT211094