Renogy ViewStar 30 Amp Negative Grounded PWM Charge Controller with LCD Display Excellent EMC design, high efficient PWM charging, nominal system voltage auto recognition. Can be use for sealed, gel and flooded battery. Dot-matrix LCD screen with backlit and HMI (human-machine interface), full control of parameter setting; charging parameters can be adjusted. Unique dual timer function; enhance the flexibility lighting systems, Automatic recognition of day and night. Temperature compensation and correcting the charging and discharging parameters automatically, improving battery lifetime. Electronic protection: Overcharging, over-discharging, overload, and short circuit; reverse protection: Any combination of solar module and battery, without causing damage to any component.