Charging up sealed lead-acid batteries - uses roughly constant charging voltage with minimal high frequency ripple and three distinct current/voltage-with-time characteristics

摘要

When charging up sealed lead-acid batteries, a roughly constant direct voltage from a rectifier is used, the voltage deviating no more than 2%, and preferably less than .8%, from its mean value. This occurs through the use of a primary or secondary circuit controller which maintains the AC ripple on the DC charging current at less than 5% of the five hour discharge current of the fully charged battery. The ripple has a frequency of at least 10 kHz, preferably at least 30 kHz. The battery uses a thixotropic gel as electrolyte. The charging uses a three stage characteristic, with constant current up to a certain voltage, falling current at this voltage to a certain minimum level, then this value current at a reduced voltage.