HQST 20A MPPT Solar Charge Controller Multiple Load Control Modes Advanced Maximum Power Point Tracking (MPPT) technology, with efficiency no less than 99.5%. High quality components, perfecting system performance, with maximum conversion efficiency of 98%. Reliable automatic limit function of maximum PV input power, ensuring no overload. LCD panel display design, dynamically displaying tool's operating data and working condition. Multiple load control modes: manual mode, light ON/OFF, light On+Timer and test mode.