Positive Battery Terminal Antenna Ground Plane

A method, comprising:

• providing a positive terminal of a battery, comprising a first electrically conductive external surface with a first surface area;
• providing a negative terminal of a battery, comprising a second electrically conductive external surface with a second surface area less than the first surface area;
• providing an antenna impedance matching circuit;
• and
• electrically connecting the antenna impedance matching circuit to the positive terminal of the battery.

A method, comprising:

• providing a negative terminal of a primary alkaline battery, comprising a first surface area;
• providing a positive terminal of a primary alkaline battery as a ground plane of an antenna, comprising a second surface area greater than the first surface area;
• providing an antenna impedance matching circuit;
• electrically connecting the antenna impedance matching circuit to the positive terminal of the battery;
• electrically connecting the antenna impedance matching circuit to a communication circuit and an antenna;
• and
• calculating data relating to the remaining capacity of the battery including corrections for load on the battery related to transmission and reception of data using the communication circuit, the antenna impedance matching circuit, the antenna, and the positive terminal of the primary alkaline battery.