To charge the battery, the output voltageof the solar panel must be higher than the current voltage of the battery. Ifthe solar panel voltage is lower than the battery voltage, the output currentwill be close to 0.General solar panels’peak voltage (Vpp) is about 17V, whichis set at the ambient temperature of 25°C. When the weather is hoter, the solarpanel's peak voltage Vpp can drop to about 15V, but in cold weather, the solarpanel's peak voltage Vpp can reach 18V.

       The mppt controller will track the maximumpower point in the solar panel. then improve charging efficiency.Theoretically, the efficiency of the solar power generation system using MPPT solar controller will be 50% higher than the traditional one, but according toour actual tests, the final efficiency can also be increased by 20%-30% due tothe influence of the surrounding environment and various energy losses. MPPT controllerwill eventually replace the traditional solar controller.