Control strategy for pulsed lead acid battery charger for stand alone photovoltaics

Lead acid batteries are still broadly used in stand alone photovoltaics. The main concerns within the use of this type of batteries are high cycling and the prolonged undervoltage state, which leads to sulfation. This work proposes a method of reverting the battery sulfation and reducing the gases formation using a three-step battery charger. A bidirectional converter in which the output current is pulsed with both magnitude and width controllable is implemented. Those pulses are used together with constant current profiles in order to increase charge acceptance and, by that, reduce the gases formation and potentially increase the battery life.