The solar charge regulator main task is to charge the battery and to protect it from deep discharging. Deep discharging could damage the battery. Regulator electronics is most sensitive and crucial to assuring stable photovoltaic system operation. Charge regulator malfunctioning result in high maintenance cost including battery replacement. An important parameter to consider is charge regulator efficiency percentage. For small photovoltaic systems charge regulators from 5 A to 30 A are available. Some of them could be used in both 12 V and 24 V DC systems.