A power device including a housing, charging circuitry, and discharge circuitry. The housing defining a first support operable to support a first battery pack, and a second support operable to support a second battery pack. The charging circuitry electrically is connected to the first battery pack and the second battery pack in a parallel-type connection. The charging circuity is configured to simultaneously charge the first battery pack and the second battery pack. The discharge circuitry is electrically connected to the first battery pack and the second battery pack. The discharge circuitry is configured to electrically connect the first battery pack and the second battery pack in a series-type connection during a discharge.