Part 4 – Charge Controllers

The solar charge controller is a critical component in your RV solar system. The controller maintains the life of the battery by preventing overcharging. When your batteries are low, the controller provides a full flow of current from your solar panels to replenish your battery banks. When your batteries achieve a 100% charge, the controller limits the current flowing from your solar panels to the batteries.

There are different types of solar charge controllers. While simple one or two stage controllers will shut off solar current when your battery is full, Pulse Width Modulated (PWM) controllers offer more functionality. They provide greater control of the current flowing from your solar panels and better ‘trickle charging’ of your batteries.

Maximum Power Point Tracking (MPPT) controllers are up to 30% more efficient than PWM controllers and provide even more control, however the high cost of MPPT controllers remains prohibitive. A top-quality PWM controller is recommended for almost all RV applications.

Buying tips

  • Cheaply made charge controllers can give off a lot of electrical ‘noise’ and interfere with some electronics like stereos and televisions. Look for a charge controller that has been UL-certified or undergone other independent standards testing.
  • Consider emerging features — options such as Bluetooth connectivity that will allow you to monitor and manage your controller remotely.