Charge controllers come in various types. Solar charge controllers regulate the charge from a solar panel array to a battery bank.
A solar charge controller will protect your batteries frombeing overcharged by your solar panels and it will block any reverse current (from the batteries) as well. Temperature sensors are an inexpensive addition that help the charge controller more accurately regulate the charge of the battery bank
Youll notice that solar charge controllers are specified by both amperage and voltage. You will need a charge controller that matches the voltage of your solar panel array and battery bank. (Usually 12, 24 or 48 VDC) And youll want to make sure the solar panel charge controller has enough capacity to handle the current (in amps) from your solar panel array.
Types of Solar Charge Controller
Many types of charge controller is right for application: MPPT, PWM, and PWM shunt controllers. A PWM (Pulse Width Modulated) charge controller is the traditional style. They are robust, inexpensive and widely used in PV applications. PWM shunt controllers are used less often and mostly in applications where electrical interference is an issue. The MPPT (Maximum Power Point Tracking), charge controller is the shining star of todays PV systems. These controllers actually detect the optimum operating voltage and amperage of the solar array and match that with the battery bank. The result is additional 15-30% more power out of your array versus a PWM controller. Although the MPPT controller is more expensive than its PWM counterpart.
Maximum Power Point Tracking solar charge controllers or MPPT charge controllers are relatively new to the solar energy industry. These charge controllers are different than the traditional charge controllers in that they are more efficient and in many cases more feature rich. MPPT charge controllers allow your solar panels to operate at their optimum power output voltage, improving their performance by as much as 30%. Traditional charge controllers reduce the efficiency of one part of your system in order to make it work with another. Several MPPT charge controllers can accept high input voltages (up to 120V+ DC) from your solar array and efficiently down convert the DC voltage to that of your system (e.g. 12, 24, 48VDC, etc.) which means you arent losing any generated power and you are able to use what you generate more efficiently. Additionally, using a much higher DC voltage on the input side allows you to use thinner wire, decreasing your wire cost and making installation easier.
MPPT is more expensive, but the return on your investment will come that much more quickly as your system performance will be significantly improved. Choosing a well-made charge controller is integral to the long life and efficiency of your entire solar power system. By optimizing the power coming in from your solar panels, youll get that much closer to offsetting your use of traditional on grid power sources and by protecting your battery supply you protect yourself from any unwanted and unneeded replacement costs. Your solar charge controller is an item well worth investing in and researching as your customize your solar panel electric system.