Residual charge indicator for electrical vehicle secondary battery - calculates residual charge of main battery from voltage or electrolyte conc. of parallel auxiliary battery

摘要

The charge indicator is incorporated in the secondary battery section (1) and uses an auxiliary battery (8) in parallel with the main battery (7), and its voltage is detected for calculating the residual charge of the main battery, to operate a display (10). Pref. the main battery has a given discharge voltage constant and the auxiliary battery has an operating voltage which varies linearly in dependence on the residual charge level of the auxiliary battery. Alternatively, the residual capacitance of the main battery is detected from the measured electrolyte conc. in the auxiliary battery which decreases linearly with the residual charge. The auxiliary battery pref. has a charge capacitance which is between a third and a tenth that of the main battery. USE - For accurate monitoring of battery residual charge when battery is in use.