In off grid photovoltaic system, solar charge controller is indispensable to protect battery overcharge and over discharge and prolong battery life. After years of development, the technology of PWM charging controller has been very mature. But we found that in the actual, after the operation of photovoltaic power station, the power generation is often lower than the original design value, which not only causes waste of the system.
Fangpusun MPPT controller is a good choice, MPPT is the maximum power point tracking, real time monitoring of the solar panel voltage, and tracking the highest voltage and current value, through the output of the highest electric energy, the system with the highest efficiency to charge the battery.
The output voltage of the solar panel must be higher than the voltage of battery. If the voltage of the solar panel is lower than the voltage of the battery, the output current will be close to 0.
PWM solar charge controllers transfer the energy of solar panels by setting parameters (or by constant voltage or constant current), which will not change according to the changes of surrounding environment. On the one hand, it is easy to cause the battery to be always in the state of insufficient charge, on the other hand, it can not make full use of the solar energy panel when the weather is good, resulting in waste.