Factors to Consider when Deciding to Purchase a Charge Controller

renogys blog May 7th 2017

A charge controller is an essential piece of equipment for all off-grid solar power systems. That being said, it is important to determine which kind of controller would best suit your system’s needs. Charge controllers come in different amp sizes and power tracking technologies: PWM (Pulse Width Modulation) or MPPT (Maximum Power Point Tracking), which can make shopping a bit confusing. Below is some information to make your charge controller search a bit easier.

Flush Mount Controllers: Renogy carries one flush mount charge controller, which is ideal for the interior of RVs or boats. The Adventurer 30A Charge Controller is a Renogy exclusive. It features PWM technology and four pre-drilled holes for easy installation. The exterior of the Adventurer contains an LCD display screen, which allows for full control of parameters settings.

PWM Controllers: PWM charge controllers feature Pulse Width Modulation charging technology. PWM controllers are more basic in the sense that they drop the voltage coming from the solar panel(s) to the batteries. This drop in voltage equates to a loss in wattage, which results in 75-80% charging efficiency.

MPPT Controllers: MPPT controllers feature Maximum Power Point Tracking Technology. MPPT technology “finds” the maximum operating point for the panels’ current and voltage under any given condition. With this method, MPPT controllers are actually 94-99% efficient. This higher efficiency can help increase the life of the battery or battery bank you are using.

LCD and LED Display Controllers: Renogy carries several charge controllers that feature LCD display screens and LED indicators. These added functions can help diagnose system faults and tell you what exactly is going on in your power system. The LED lights, for example, can help you determine whether the system is on and functioning properly. An LED display screen shows various icons as well as numerical data to tell you how well the system is working. All Renogy charge controllers feature LED lights, while the Commander, Rover, and Adventurer, and Viewstar also feature LCD display screens.

Why are charge controllers important: Charge controllers are an essential piece of equipment because they prevent the battery from charging over 100%. Once the battery is nearing full charge, the controller slows the amount of electricity flowing to the battery. When the batteries aren’t otherwise being used, the charge controller can “float” charge the battery, or continuously top off the charge to prevent the battery from dying.