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Please contact an Authorized Sony service/Support Center to have the battery pack in your VAIO Duo, Pro or Fit notebook replaced with a new one. It cannot be removed by yourself.
Battery life cycle explainedThe capacity of your notebook battery gradually declines through repeated cycles of recharging and discharging. As a result, the battery life becomes short even if it is fully charged and eventually the battery pack reaches the end of its life.
If the battery pack quickly runs out of power after being fully charged or it has reached the end of its life, have it replaced with a new one.