A charge controller regulates a battery’s SOC, providing full power when necessary and reducing the charge when the battery’s SOC is at sufficient levels. This is important for maintaining the state of health of the batteries installed.

There are two types of charge controllers that are available:
PWM stands for “Pulse Width Modulation” and is basically a 3-stage charging cycle type controller. Most of your DC applications use this technique for lower power ratings typically up to 2 KVA.
MPPT stands for “Maximum Power Point Tracking”. This is a new type of controller that not only provides multi-stage charging but also delivers more power to installed batteries by comparing PV voltage with battery voltage, thus delivering the best current to charge your batteries. This makes it more efficient as compared to a PWM charge controller.