The present invention includes a system and method of charging a rechargeable battery. The system can further include a processor that is adapted to control one of the high power charger or the low power charger to charge the battery in response to the high power input voltage relative to a predetermined high power voltage value and the low power input voltage relative to a predetermined low power voltage value. The method can include the steps of determining a high power input voltage of the high power source, determining a low power input voltage of the low power source, causing a high power charger to charge the battery in response to a sufficient high power input voltage, and causing a low power charger to charge the battery in response to an insufficient high power input voltage and a sufficient low power input voltage.