Newer Sony laptops come with "Battery Care" software that automatically keeps the battery between 50 and 80% at all times. According to Sony engineers, a battery that is always kept at or below 50% will essentially never degrade in capacity.
Plus, charging from 20 to 80% is much faster than charging from 20 to 100% (I estimate that about half of the time is spent just going from 80 to 100).