Battery charging apparatus and method

摘要

A battery charger and associated method for charging a DC battery utilizes a step-down transformer with high leakage reactance, and means for rectifying and regulating the step-down transformer output to continuously supply a constant charging current to the battery. Feedback from a current sensing means in series with the battery is provided for determining proper regulation. A discharge current controller in parallel with the battery contains a load resistor and switching means electrically responsive to a pulse train generator. The discharge current is applied to the battery in a rapid succession of brief pulses throughout the entire charging cycle, with the discharge current pulses being superimposed over the charging current. The discharge current pulse duration is selected utilizing the pulse train generator, between 50 and 100 microseconds with a time period on the order of twenty times the pulse duration. The amplitude of the discharge pulses, fixed by selection of the load resistor, is approximately three times the magnitude of the average nominal charging current. The rapid application of high amplitude current for an extremely brief pulse duration induces electromagnetic forces within the battery. A turbulence is produced which advantageously scrubs the battery plates to remove hydrogen bubbles, so the entire plate surface is available for the redeposition of ions.