An electrical device, such as a power tool, includes a first battery pack receptacle configured to receive a first battery pack and a second battery pack receptacle configured to receive a second battery pack. The second battery pack is electrically connected in a series-type configuration with the first battery pack. The electrical device also includes circuitry with an electronic processor. The circuitry is configured to alter a first signal output from the electronic processor to at least one selected from a group consisting of the first battery pack and the second battery pack, and to alter a second signal received by the electronic processor from at least one selected from the group consisting of the first battery pack and the second battery pack.