Abstract: A charging station for charging electrical vehicles and comprising battery pack(s). The battery pack(s) comprise(s) batteries coupled in series and a control unit for controlling the batteries individually. Each battery (1) comprises battery cell(s) with a battery inlet line and a battery outlet line, an electrical circuit element arranged to lead from the battery inlet line to the battery outlet line to form an electrical path leading around the battery cell, and one switch. The switch is arranged in the battery outlet line or the battery inlet line and is switchable between first and second positions. The control unit is connected to the switch of each battery and is adapted for controlling the switch to switch between the first position, in which an electrical power is lead through the battery cell, and the second position, in which the electrical power is lead through the electrical circuit element.