Mains will be used only when the battery voltage is below a preset voltage (adjustable). When mains is on, Solar and Mains do not load each other like in other UPSs, but the charging is done with the intelligently shared current. An outstanding feature is that if the UPS gets overloaded while working on Solar, the load gets shifted to Mains, automatically. Again when the Battery charge reaches a preset high level, Mains is cut off and the load gets shifted to Solarbattery.