Abstract: A common battery for providing power to a first of a plurality of radios. The plurality of radios includes at least a first radio and a second radio. The common battery has a size of the smallest of at least two batteries. The common battery comprises a raised concentric wall edge for enabling the common battery to lock in place when used in place of a larger of the first battery and the second battery, such as within a Vehicular Adaptor Amplifier. The raised concentric wall edge has a height of a difference between a height of the first battery and a height of the second battery. In one variation, the common battery comprises a circular piloting interface that uses an outside radius of a respective bayonet connector on the first and second radios to align the common battery to the respective radio.