Do I need a charge controller?
Yes, charge controllers are a critical part of solar installations. The only exception to needing a charge controller is if you have small panels smaller than five watts. The solar charge controller sits between the solar panels and battery bank and prevents overcharging of batteries by limiting the amount and rate of charge to your batteries. Solar charge controllers also prevent battery drainage by shutting down the system if stored power falls below 50 percent capacity. This helps preserve the life and health of the batteries.
What are the different types of charge controllers?
There are two types of charge controllers to consider: Pulse Width Modulation (PWM) controllers and Maximum Power Point Tracking (MPPT) controllers. PWM charge controllers are an older technology and are cheaper, but less efficient than MPPT charge controllers. Both are widely used, have similar lifespans, and preserve the life of your batteries.
What size charge controller do I need?
Charge controllers are sized based on the solar array's current and the solar system’s voltage. You typically want to make sure you have a charge controller that is large enough to handle the amount of power and current produced by your panels. If your solar system's volts were 12 and your amps were 14, you would need a charge controller that had at least 14 amps. However due to environmental factors, you need to factor in an additional 25%. This brings the minimum amps that this charger controller must have to 17.5 amps. In this example, you would need a 12 volt, 20 amp charge controller.