THERMALLY RESPONSIVE BATTERY CHARGER

摘要

A battery charger (10) includes a capacitor (20) which establishes a level of current sufficient to fast charge a battery (18) having from one to twenty cells. An SCR (16) is controlled by a timer (42) to initially delay the supply of current while determining whether the battery (18) is hot or cool. If battery (18) is cool, charger (10) proceeds to fast charge the battery. After battery (18) is fully charged, the battery heats to a temperature where an NTC thermistor (58) responds to trigger a second timer (52) which controls SCR (16) to stop the fast charging operation. Charger (10) is then controlled to prevent the charger from thereafter re-entering a fast charge mode. If battery (18) is initially hot, charger (10) is controlled to further delay the initiation of a fast charge operation until the battery cools to or below the charge-start temperature. A second NTC thermistor (90) is provided to compensate for the potential effect on the operation of the thermistor (58) in response to temperature levels emanating from any environment other than from the battery (18).