Optimized for a 12V system; Deep cycle Sealed, Gel, Flooded, and Lithium battery option ready. Smart 4 Stage PWM charging (Bulk, Boost, Float, and Equalization) and temperature compensation increases battery life and improves system performance. Intelligent protection against reverse polarity, overcharging, short-circuit, and reverse current. Multiple LED indicators for easy to read charge status and battery information. Integrated RS232 port allows communication with BT-1 Bluetooth module and usage of Renogy BT smartphone app. The Renogy Wanderer-Li is a 30A PWM solar charge controller that integrates efficient PWM charging to increase battery life and improve system performance. Designed with a simple interface for ease of use, the controller uses multiple LED indicators to notify users of charge status and battery information. This newly improved model has two advanced features: an RS232 port and Lithium battery charging. With the addition of the RS232 port, users can now connect and communicate with the Renogy BT-1 Bluetooth module. By adding the BT-1 to the Wanderer-Li, you can now use the smartphone app, Renogy BT, to monitor and adjust your solar system remotely. With the inclusion of the Lithium Battery Mode, the 30A negative-ground controller is now capable of charging various 12V battery types and banks, including most 12V lithium models available on the market.