Battery charger for charging both a frequently and infrequently used battery

摘要

A battery charger used to charge a battery has a voltage detector for detecting a voltage across a battery, a memory for storing detected voltage values, and a comparator for comparing a presently detected voltage with a previously stored voltage. If the detected voltage decreases below a certain value before a predetermined period of time elapses, it is determined that a battery that has been in storage for a long period of time is connected to the battery charger. The battery charger will then apply a constant current to the battery until a second predetermined period of time has elapsed.