fr A completely discharged battery will have a voltage below 11 volts. As it is charged, the voltage rise, to get around 14.5 volts. After this threshold, it is better not continue to recharge your batteries, otherwise, their life time might decrease. This is where the use of a regulator becomes important. There are two main branches of regulators: the load diverters and PWM. The load diverters are not used to regulate the voltage of wind turbines or solar panels, but to regulate the battery's charging.

That way, when the batteries get full, the load diversion controller turns on and starts diverting the surplus power to another power source, such as heating water, air, or lighting. On the other hand, the PWM charge controller will cut the power supplied to the batteries, as soon as they get full. The result is inevitably a loss of energy. A system using a load diversion controller will protect your batteries against over-charging, but your wind turbines and / or solar panels will never be disconnected from the batteries.

Now we can find on the market various types of PWM controllers. Most of them include the MPPT function that has the task of maximizing the output current of the solar panels. The MPPT controllers are the same as the PWM controllers, but will provide you about 25% more amperage from your solar panels.