Based on common negative design and advanced MPPT control algorithm, with die-cast aluminum design for heat dissipation, products in this series are artistic, economical and practical. With MPPT control algorithm, in any situation, products of this series can fast and accurately track out the best maximum power point (MPP) of photovoltaic array, in order to obtain the maximum solar energy in time, which remarkably improves energy efficiency. With Modbus communication protocol interface, it is convenient for customers to expand applications and monitor in various fields like telecommunication base station, household system, caravan system, street lighting system, wilderness monitoring system, etc. All-round electronic fault self-test function and enhanced electronic protection function could furthest avoid damages on system components resulting from installation errors or system failures. 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%. Ultra-fast tracking speed and tracking efficiency. Accurately recognizing and tracking of multiple power points. Reliable automatic limit function of maximum PV input power, ensuring no overload under any circumstance. Wide MPP operating voltage range. Die-cast aluminum design, ensuring excellent heat dissipation characteristic. Multiple load control modes: manual control, light ON/OFF, light On+Timer and time control. 12/24VDC automatically identifying system voltage or user-defined working voltage. LED indicators showing system status, simple and clear. Support 4 charging options: Sealed, Gel, Flooded and User.Battery temperature compensation function. Real-time energy statistics function. With RS-485 communication bus interface and Modbus communication protocol, it is available to meet various communication requirements in different situations.Available for PC monitoring and external display unit connecting like MT50 and so on, realizing real-time data checking and parameters setting. Support software upgrade. The controller connection sequence is Battery--Load--Solar Panel, and discounect the system in the reverse order Solar Panel--Load--Battery The Tracer-BN series is a negative ground controller. Any negative connection of solar, load or battery can be earth grounded as required.Notice： 1）Unplug the RTS, the temperature of battery will be set to a fixed value 25 ºC. 2）Please connect the inverter to the battery rather than to the controller, if the inverter is necessary. 3）The RS-485 port and RTS port is not SELV circuit, it must have isolation between the port and the place where the end user can access directly. Four methods to configure the controller: Remote meter, MT50 (Use standard twisted net cable, model:CC-RS485-RS485-200U-MT). Super parameter programmer, SPP-02(Use standard twisted net cable, model:CC-RS485-RS485-200U). One-key easily configure and apply to batch setting.PC monitoring setting software ―Solar Station Monitor‖（Use USB to RS485 converter cable with model: CC-USB-RS485-150U.Mobile APP (Use USB to RS485 converter cable: CC-USB-RS485-150U and Micro 5PIN OTG cable) 3215BN MPPT Solar Charge Controller 12V/24VDC Auto Working150V Max. PV Open Circuit Voltage390w(12v)/780w(24v) Max. PV Input PowerSupport 4 charging options: Sealed, Gel, Flooded and User Remote Meter (Model：MT50) Wide LED screen displays the real time operational data and the working status in digital, graphic and textual forms. Basically used for monitoring and setting the controller, it automatically identifies the type, model and relevant parameter data of solar controllers. Remote Temperature Sensor (Model: RTS300R47K3.81A) Acquisition of battery temperature for undertaking temperature compensation of control parameters, the standard length of the cable is 3m. The RTS300R47K3.81A connects to the port on the controller. NOTE: Unplug the RTS, the temperature of battery will be set to a fixed value 25ºC. USB To RS-485 converter (Model: CC-USB-RS485-150U) USB To RS-485 converter is used to monitor each controller on the network using Solar Station PC software and update the firmware.The length of cable is 1.5m.