ABSTRACT
A charge controller regulates the charging and discharging of the battery. The two most common types of charge controllers are pulse width modulation (PWM) and maximum power point tracking (MPPT). PWM quickly changes between voltages to control charging. MPPT is able to modulate the voltage and current to achieve the most efficient power production for a PV system. Other features are available for controllers such as voltage stepdown for high voltage arrays and data monitoring. Smaller charge controllers have fewer options, while larger ones have separate load control switches and relays. Larger controllers can be used to automatically start backup power generators, monitor battery temperatures, and send alarm notifications. Controllers must be able to pass the volts, amps, and watts that the system can produce. Monitors are important for verifying information displayed on controllers and inverters. Example of a controller for a 24V PV array with battery backup.
