Solar Charge Controllers

Solar charge controllers manage the energy coming from the solar panels into the battery. In practical terms, they protect the battery from overcharging, improve charging performance and make sure the solar side of the system is doing something useful rather than merely existing on the roof.

For most campervan, leisure and small off-grid systems, the right choice is an MPPT controller. MPPT controllers are more efficient than older PWM types, especially where panel voltage is higher than battery voltage or where light conditions change through the day. In the real world, that usually means better harvest, better charging behaviour and a battery that gets treated rather more properly.

If you are choosing between models, the key things to compare are maximum PV open-circuit voltage, rated charge current and whether the controller suits the planned battery voltage and likely system growth. The aim is not to buy the biggest unit for the sake of it, but to choose a controller that genuinely matches the array and battery system you are building.