Patent ID: 8134339

Claim:
A method for preserving a battery's charge and protecting electrical devices each receiving power from an output port of a respective power control circuit coupled to the battery in a vehicle, comprising: measuring a steady state battery voltage at the output port; comparing, by a processor, the measured steady state battery voltage value to high and low battery voltage thresholds, wherein said high battery voltage threshold is based on a design characteristic of said battery and an upper voltage threshold limit of an electrical device receiving power from an output port of said power control circuit, and said low battery voltage threshold is based on a design characteristic of said battery and a lower voltage threshold limit of said electrical device; if the measured steady state battery voltage value is greater than the high battery voltage threshold, reporting an over voltage state; if the measured steady state battery voltage value is less than the low battery voltage threshold, reporting a low battery voltage state; in response to the over voltage state, sending, by the processor, a first power control signal to the power control circuit to vary the voltage or current at the output port; and in response to the low battery voltage state, sending, by the processor, a second power control signal to the power control circuit to vary or remove the voltage or the current at the output port.