Device with multiple, concurrently-installed power modules and method for controlling same

A set of power modules for providing a DC voltage to a device when one or more of the power modules is installed therein, the set of power modules comprising:

• a rechargeable battery pack including a first housing, one or more rechargeable battery cells and a battery charger mounted within the first housing, wherein the battery charger applies a charging voltage to the battery cells, the charging voltage being derived from an externally-applied DC voltage, and wherein the rechargeable battery cells generate a first DC voltage suitable for use by the device;
• a non-rechargeable battery pack including a second housing and one or more non-rechargeable battery cells mounted within the second housing, wherein the non-rechargeable battery cells provide a second DC voltage suitable for use by the device;
• and
• an AC power pack including,
• a third housing,
• an AC-to-DC converter mounted within the third housing, and
• an electrical interface for providing an externally-applied AC voltage to the AC-to-DC converter, wherein the AC-to-DC converter converts the applied AC power to a third DC voltage suitable for use by the device,
• wherein the electrical interfaces for the rechargeable battery pack and the non-rechargeable battery pack and the AC power pack have different pin assignments within the same configuration.