system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If it's bad for the battery for a computer to be plugged in while at 100% charge, why can't the charger detect a full charge and disconnect the power?
gpt
It can and does.

(Speaking for Lithium-Ion batteries)

If it didn't, the battery would overcharge, which would result in the battery failing (possibly catastrophically, read: explosively).

What's bad for the battery is remaining at 100% battery for extended periods of time.  It can result in the chemicals in the battery becoming crystalized, and unable to discharge.  

Imagine if you had a bottle of water and ice formed if you left it filled for too long, and that ice never melted.  The total drinkable capacity of the water bottle would be reduced by the ice.