Recover full battery capacity

If your computer is constantly plugged in to an electrical outlet and the battery rarely discharges, the battery may not be charged to its full capacity even if the battery meter reports 100% charge. You can recover the battery’s full charging potential simply by discharging and re-charging the battery.
  1. Unplug the computer and use it until the battery charge drops below 20%.
  2. Plug in the computer and charge the battery to 100%.