Grape Solar GS-PWM-165W PWM Solar Charge Controller, 165-watt Digital display shows charging current, discharge current and battery bank capacity Allows for parallel connections of smaller panels, ideally suited for grape solar panels 160 watt and less Dual USB ports for directly charging portable devices, 3 stage charging method: bulk, absorption and floating Pwm technology works on only low voltage panels See manual for more details on PWM charge controller