Abstract: A method mitigates or even prevents gas swelling of a battery of a portable electronic device at high temperatures and states of charge of the battery. The method comprises: receiving “temperature” and “state of charge” signals, which are functions of a temperature and state of charge of the battery, respectively; determining, as corresponding functions of the “temperature” and “state of charge” signals, whether the temperature is within an elevated operating-temperature range and the state of charge is within an elevated state-of-charge range; cycle-forming the battery a predetermined number of cycles; and terminating the “cycle-forming” operation of the battery when the pre-determined number of cycles is reached.