摘要 |
A system for providing an accurate indication of the remaining life of a battery. The system includes a first circuit that provides a control signal. A second circuit employs an internal resistance value of the battery and a battery voltage to provide the indication of remaining battery life in response to the control signal. In a specific embodiment, the second circuit includes a third circuit that measures the internal resistance of the battery in response to the control signal. The third circuit also includes a circuit for measuring an output current and an output voltage of the battery at varying battery loads. The circuit for measuring an output current includes an ammeter and a switching load. In a more specific embodiment, the switching load is implemented as a transmitter that is selectively activated via the control signal. A fourth circuit, included in the second circuit, provides the indication of remaining battery life in response to the internal resistance. The fourth circuit also includes a circuit for selecting a battery discharge curve in accordance with the internal resistance. Software running on the first circuit generates the estimate based on the discharge curve, which is subsequently displayed via a display. |