US Patent 11031686 Positive battery terminal antenna ground plane

A positive terminal of a battery may act as an antenna ground plane for communicating battery status information. The positive terminal of the battery may include a first electrically conductive external surface with a first surface area. The negative terminal of the battery may include a second electrically conductive external surface with a second surface area less than the first surface area. An antenna impedance matching circuit may be electrically connected between a communication circuit, an antenna, and the positive terminal of the battery. Thus the positive terminal of the battery may act as a ground plane for the antenna.