A power tool may include a housing that supports an electrical circuit. The electrical circuit may include at least two terminal sets that are arranged in parallel to each other. The at least two terminal sets may include a first terminal set configured for engagement along a first axis to a battery pack having a first configuration and a second terminal set configured for engagement along a second axis to a battery pack having a second, different configuration. A battery charger may include a housing, and an interface that is electrically and mechanically compatible with at least two battery packs having different configurations and battery cell chemistries.