Inventors:
Richard B. Alexander - Clear Lake IA
Dennis P. Kindschuh - Mason City IA
Assignee:
Alexander Manufacturing Company - Mason City IA
International Classification:
H02J 710
Abstract:
The characteristic voltage-versus-time curve for a nickel-cadmium battery on a fast charge, e. g. , being charged at the C/1 rate, increases to a peak voltage and thereafter decreases. To ensure that the battery is fully charged, the fast charge is discontinued on the decreasing portion of the voltage-versus-time curve. The fast charge may be stopped when a predetermined negative rate of change of the voltage is obtained. Or the fast charge may be cut off when the battery voltage decreases a predetermined amount below the peak, that is, when the difference between the maximum measured battery voltage and the present battery voltage exceeds a setpoint. After the fast charge is discontinued, a trickle charge, e. g. , a C/10 charge or less, may be instituted or the charging current may be interrupted altogether, i. e. , the battery charging circuit may be opened.
