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What & Why: Charge Controllers

PWM & MPPT charge controllers

Charge Controllers & Your Renewable Energy System

If you’ve checked out our Renewable Energy System Diagram, you know all alternative energy systems use a charge controller between the power source (solar, wind or hydro) and the battery bank. In simple terms, the charge controller regulates the power delivered to your battery bank, to prevent damage to either the batteries or the power source. But when you actually go to buy a charge controller for your system, choosing the right one from all the models available can be daunting.

Of course it needs to be sized appropriately for the amount of power you’ll be generating, but beyond that there’s load-diverting controls, pulse-width-modulated (PWM) models, and something called Maximum Power Point Tracking (MPPT). Knowing which controller is best for you may seem confusing. In this post, we’ll explain all that terminology, and make sure you know everything you need to choose the right type of charge controller for your needs!

Load-Diverting vs. Solar Controllers

Solar panels and turbine-based generators (wind or hydro) require different kinds of charge controllers. In short, solar panels only produce power when power is actually needed (when an electrical load is connected), so a solar controller just needs to be able to shut off the flow of electricity when your battery bank is fully charged, to prevent damage to the batteries. Wind and water turbines, on the other hand, produce power whenever they are in motion. Having an electrical load connected helps control the speed of the generator, and the turbine can be damaged if it’s left to spin uncontrolled when no power is needed.