A Solar Home System includes Solar PV, battery, and solar charge controller. In most cases solar energy consumer use solar energy at evening hours, but it is available in day time. So, it is required to store solar energy into battery. A solar charge controller, or charge regulator is similar to the voltage regulator. It regulates the voltage and current coming from the solar panels and goes to the battery. Most of the batteries are fully charged at 14 to 14.5 volts. On the other hand, battery’s life time drastically reduces due to the discharge over the level of 70%-80% DOD; at this discharge level the battery voltage normally goes down to 11.5±0.2 volts. Each battery has certain limit of capacity. Battery lifetime reduces due to overcharging and deep discharging. As battery is a very expensive component of Solar Home System. So, it is essential to protect the batteries from over charging and deep discharging. In this case charge controller plays a vital role to protect this battery.... Это и многое другое вы найдете в книге Low Cost Solar Charge Controller (Mohammad Shariful Islam)