Measurement and display system for vehicle battery - uses initialisation and control devices to measure voltage with open circuit and after loading to determine state of charge

摘要

The system for monitoring a subassembly within the electrical circuit of a vehicle includes initialisation, monitoring and display circuitry for checking the state of the battery. The monitoring circuit measures the internal resistance of the battery, and/or the open circuit voltage. A specified current is then drawn for a given time, e.g. 10A for 100 mS, and the voltage is then measured again. These voltages are then compared, in order to evaluate a measurement of the state of charge of the battery. The circuit may take account of other factors, such as temperature. ADVANTAGE - Display of additional information to driver of vehicle, giving battery status.