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Solar panel charge controller

Photovoltaic cells (PV cells) generate electricity under the influence of light. Depending on the type of PV cells and its use, the electricity can be used when generated, sold to electric utility companies, or stored for later use.

Storage is usually achieved by using a battery or battery array. A solar cell can not be connected directly to the battery so the charge controller is used.

Most 12-volt solar batteries out put some 16 to 20 volts, so if there is no regulation of the battery will be damaged by excessive charging. Most batteries need around 14 to 14.5 volts to get fully charged.

Charge controllers regulate the battery and prevent excessive charging and damage to the battery. They also add protection to prevent any leakage of current from the batteries to photovoltaic cell at night.

Charge Controller

The obvious question, why solar panels don’t just output 12 volts. The reason is that if they did this, the panel will only generate electricity when the cold and under ideal conditions i.e. when the sun is at its most intense.

This is not something that you can count on a majority of areas. The panels should provide the additional voltage that, when the sun is low in the sky, or you have a heavy haze, cloud cover you still get some output from the panel. A fully charged battery is about 12.7 volts, therefore the panel must produce this under the worst conditions.

The cost of the charge controllers range from $ 25 U.S. to $ 500 dollars depending on the complexity and current rating. But the average range of the controller should have the following functions: measuring and displaying battery voltage and ampere, temperature compensation, three-phase charging (equalization, boast and float) and low voltage disconnect.