Features 1High Efficiency: Maximum power point tracking technology that is MPPT algorithm enables the controller to track the maximum power point of the solar panel with faster response and higher efficiency. 2Stable Charging: Using active charging voltage regulation and digital power technology when the battery is open circuit or overcharged the battery terminal of the controller will output the rated charging voltage value. 3Extensive Using: Supports charging procedures for various types of batteries such as lithium batteries gel batteries sealed batteries ventilated batteries lithium batteries etc. 4Higher Security: Enables current limited charging. When the power is too large and the charging current is higher than the rated threshold the controller will auto reduce the charging power to work under the rated charging current and supports auto recognition of the battery voltage. 5Smart Operation: Can be connected to an external LCD screen or a Bluetooth module to view the operating data and status of the device and support to modify the controller parameters. 6Other Functions: Built in over temperature protection temperature compensation automatic adjustment of charge and discharge parameters solar panel short circuit protection battery open circuit protection and so on. Specification Item Type: Solar Charge ControllerMaterial: Aluminium AlloyCharging Current: 30ADischarge Current: 30AMaximum PV Power: 400W 12V 800W 24V Package List 1 x Solar Charge Controller1 x User Manual Note Pay attention to electricity safety when using.