Solar Charge Controller

A solar charge controller is used to regulate the energy flow from the solar panels to the battery by adjusting the parameters of Intensity (I) and Voltage (V). There are typically two types of charge controllers: MPPT charge controller and PWM charge controller.

What's the difference?


The two types of charge controllers most commonly used in today’s solar power systems are pulse width modulation (PWM) and maximum power point tracking (MPPT). Both adjust charging rates depending on the battery's charge level to allow charging closer to the battery’s maximum capacity as well as monitor battery temperature to prevent overheating.

Array Voltage

PV array & battery voltages should match.

PV array voltage can be higher than battery voltage.

Battery Voltage

Operates at battery voltage so it performs well in warm temperatures and when the battery is almost full.

Operates above battery voltage so it is can provide “boost” in cold temperatures and when the battery is low.

System Size

Typically recommended for use in smaller systems where MPPT benefits are minimal.

≈ 150W – 200W or higher to take advantage of MPPT benefits.

Array Sizing Method

PV array sized in Amps (based on current produced when PV array is operating at battery voltage).

PV array sized in Watts (based on the Controller Max. Charging Current x Battery Voltage).

MPPT vs PWM solar charge controller
Charge Controller

MPPT vs PMW: Charge Controller Comparison and Buyer Guide

A solar power system typically includes a solar panel or array that generates electricity, a battery bank that stores the electricity for later use, and an inverter that converts the DC power from ...