How to use an auto 12-volt regulator for a solar panel

Updated July 20, 2017

If you plan to use solar energy on a large scale, you will need a battery bank of deep cycle 12-volt batteries. To keep your battery bank fully charged and functioning optimally, you will need to install a charge controller between the solar panel array and the battery bank. Without the charge controller, the batteries could overcharge. Overcharging depletes battery life and causes batteries to leak and even explode. Take care of your solar power system by installing this simple mechanism.

Find a charge controller that has the correct specifications for your solar panel array. The charge controller must be able to handle the amperage load of your solar array. In many cases a 45-amp charge controller with a 50-amp fuse will be sufficient, however it is best not to leave it to chance. Consult an electrical professional or a detailed guidebook on constructing solar energy generators. You can purchase charge controllers from a variety of online retailers as well as local electronic parts stores.

Connect the charge controller to your system between the solar panel array and the battery bank. Depending on the gauge of the existing wiring, you may solder it in place or use nuts and bolts to clamp the wires together.

Set the charge controller to turn the electrical current from the solar panels on when the charge of the battery bank drops below 11.7 volts and to shut the current off when the charge of the batteries exceeds 14.3 volts.

Allow the solar array to charge your battery bank normally. Once the system is charged, you are ready to safely use the electricity you have stored.


Invest in a proper charge controller that will not only prevent the solar panels from overloading your battery bank, but will also keep the solar array from draining the battery system at night.


Mishandled batteries can be dangerous. If you have any doubts about your system, consult a professional.

Things You'll Need

  • Charge controller
  • Soldering iron
  • Solder
  • Nuts and bolts
  • Adjustable wrench or socket set
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About the Author

Joe Capristo began writing professionally in 2005. He has experience in public education, writing documents, lessons and teaching materials for Guilford County Schools. Capristo has a Bachelor of Arts in English from the University of North Carolina at Greensboro.