What is a Charge Controller?

A charge controller is an important part of power systems that moderates the level of energy entering and leaving your batteries. While the right charge controller will protect your batteries from overcharge and excessive discharge, any charge controller will ensure its base function: to maximize the lifetime of your energy storage.

Your perfect charge controller is closer than you think, but many options exist to suit your particular needs. Some base criteria for selecting a charge controller are as follows:

  1. What is the operating solar PV voltage and the solar PV panels rated current?

    A solar charge controller should be able to handle the rated current of all the panels combined.


    • One 85W solar panel is rated at 5.02 amps. As a result, your selected controller should handle 5.02 amps.
    • Two 85W panels connected in parallel are rated at 5.02 amps + 5.02 amps. Knowing this, your selected controller should handle 10.04 amps.
  2. What kind of mandatory/optional features do you want for your charge controller?
    • Is an indicator required to indicate the solar panel and charge controller is working?
    • Would an LED charging indicator be sufficient or would you rather have a meter that displays battery voltage and charging current?
    • Is conformal coating an important feature?
    • Is Gel, AGM, lead-acid, or lithium-ion battery selection important?
    • Do you need to be able to connect to your charge controller with your smartphone (or any other Bluetooth-enabled device)?

    With so many options on the market, consider your preferences and requirements before purchasing!

  3. Do you need an MPPT charge controller?

    MPPT charge controllers maximize the effiiency of the power transfer from solar panels to the battery through use of Maximum Power Point Tracking (MPPT). An MPPT charge controller constantly seeks the maximum power point on your solar panel to transfer its energy.


    • Given a 17V output from a solar panel, an MPPT charge controller might reduce the voltage to only the 13V required to charge your battery. Furthermore, during conversion, the current increases from the solar PV panel up to a possible 25%.
  4. Would a Diversion Load Controller be more suitable for your installation?

    A Diversion Load Controller monitors your battery voltage and limits its maximum value by diverting some of that energy into loads.

    When used in combination with solar PV panels, a diode is inserted between the solar panel and the battery bank eliminating discharge power in the evening. Most Diversion Load Controllers use a resistor to dissipate the excess energy in the form of heat, or, in some cases, the energy is placed into an onboard hot-water tank.

If you need further assistance finding your perfect charge controller, feel free to contact us and any of our knowledgable salespersons will be happy to assist you!