초록 ▼

A method and apparatus for efficiently charging lead-acid batteries applies small voltage steps to probe the charging efficiency of a battery being charged. The application of a voltage step causes the current to change from a base current to a surge current immediately after the voltage step, and t

A method and apparatus for efficiently charging lead-acid batteries applies small voltage steps to probe the charging efficiency of a battery being charged. The application of a voltage step causes the current to change from a base current to a surge current immediately after the voltage step, and to decay asymptotically to a plateau current after the surge current. A current ratio, defined as the difference between the plateau current and the base current divided by the difference between the surge current and the base current, is used as an indicator of the charging efficiency. The output voltage of the power supply charging the battery is then adjusted according to the measured current ratio. A current-voltage slope, defined as the difference between the plateau current and the base current divided by the magnitude of the voltage step, may also be used as an indicator of the charging efficiency for controlling the charging process. Alternatively, in a current-controlled charging process, small current steps are used to probe the charging efficiency. For a current step, the induced voltage changes are measured, and a transient-plateau voltage ratio is calculated. The charging current is then adjusted according to the calculated voltage ratio.

대표청구항 ▼

[ What is claimed is:] [1.] A method of controllably charging a battery over a charging period, comprising the steps of:connecting a charging voltage to the battery;applying a plurality of separate and distinct voltage steps in the charging voltage to the battery, the plurality of voltage steps bein

[ What is claimed is:] [1.] A method of controllably charging a battery over a charging period, comprising the steps of:connecting a charging voltage to the battery;applying a plurality of separate and distinct voltage steps in the charging voltage to the battery, the plurality of voltage steps being distributed over the charging period and each having a step magnitude significantly smaller than the charging voltage applied to the battery, for each of the plurality of voltage steps:detecting current changes induced by said each voltage step;calculating a ratio from the detected current changes; andvarying the charging voltage according to the ratio.