If it works as intended, it is precicesly what’s needed (and other laptops, including thinkpads, enable/do). That’s because:
- The battery recalibrates itself frequently, so the reported charge can move in either direction. If you haven’t already, go through that thread, especially the most recent half of it, it’s very informative.
- It’s preferable to keep the battery idle (not charging or discharging) as much as possible. If the machine is plugged into an adapter that provides enough power, let’s let the battery slooooooowly discharge (self discharge) which should be days per 1% of charge.