BATTERY PACK DISCHARGE RECOVERY CIRCUIT

摘要

A charging circuit (10) for a lead-acid battery pack (11) includes a sacrificial battery (30) with a voltage less than that required to charge the lead-acid battery (11) and connected across the input terminals (18 and 19) of a power converter (20), which boosts the sacrificial battery voltage to an output voltage sufficient to charge the battery pack (11). A processor (14) operating under stored program control is connected across the lead-acid battery (11) and monitors its voltage and produces an output signal when the voltage drops below a predetermined level, for triggering the power converter (20) to apply its boosted voltage to the lead-acid battery (11) for charging. The processor program ignores normal battery voltage conditions which occur during normal operation of an associated device powered by the lead-acid battery (11) and will activate the power converter (20) only when the lead-acid battery voltage has reached a significantly low level or has reached a low level for a sufficiently long period of time, to be consistent with a deep discharge condition of the lead-acid battery (11).