Battery charger capable of accurately determining fully charged condition regardless of batteries with different charge chracteristics

摘要

To provide a battery charger capable of fully charging both an active battery and an inactive battery, which have different charging characteristics near the peak level, a voltage across the battery is periodically sampled during charging the battery. A voltage change is obtained by subtracting a voltage that has been sampled previously from the newly sampled voltage. Determination of the fully charged condition of the battery is made when a voltage change falls below a critical value (S1, S2) after identifying that the battery being charged is an active or inactive battery using another critical values (K1, K2 or K1, K2). The critical values S1 and S2 and another critical values K1 and K2 (or K1 and K2) are selectively referred to depending to the battery voltage change.