Description:       CM20D-USB 10A\/20A 12V\/24V AUTO LCD USB Solar Charge Controller Solar Panel Battery Charger Controller Light Timer Control    CM20D controller is a kind of intelligent、 multi-purpose solar charge and discharge controller. Fixed LCD display with a very friendly interface is used in this product; various control parameters can be flexibly set、 fully meet your various application requirements.   This is a settable charge controllers: 1. Floating charge Voltage(HVD 13.3V-15V) 2. Recovery after under Voltage(LVD 11V-13.5V)  3.Under Voltage protection (RVD 9V-12.3V)  4.Load Mode(24hours、1-23hours、0hour) 5.Battery Option (GEL、LEAD-ACID、FLOODED)               Features:                Visual LCD graphic symbols         Simple button operation               Automatic Identification of System Voltage level         Intelligent PWM charging mode               Automatic Temperature Compensation (custom)         Adjustable charge-discharge control parameters               Settable Operating mode of Load         Battery reverse-discharge protection               Battery Low Voltage Disconnection (LVD)         Battery reverse connection protection               Over current protection.                          P1: Digital parameters.    P2:Charging indication. This symbol indicates that the  solar panel is charging the battery; without this symbol  means solar panel can not charge the battery because of low voltage. If the symbol is flickering、 means the battery is fully   charged and has entered float charging state.    P3:Indication for solar panel. This symbol indicates that the connection of solar panel is detected by controller; without this symbol means the connection of solar panel can not be detected、 or there is no sunshine on the solar panel.   P4:5 bars battery power indication.   P5: Discharging indication. This symbol indicates that controller is in output state、 otherwise not in the output state. The flickering of this symbol indicates the damages of internal control devices.   P6:load indication. This symbol indicates that controller is in output state、 otherwise not in the output state. The flickering of this symbol indicates overload or the damage of the load.    P7:A stands for the unit of current; H stands for hour.   P8:V stands for the unit of voltage.       Specification:                        Type Parameters                    CM20D                    Type   Parameters            CM20D                   Rated current           10A           20A           Charge and discharge voltage drop           <0.2V|<0.1V                   Rated voltage           12V\/24V Automatic Identification           Charging mode           PWM mode                   Voltage of solar panel           ≤50V           Temperature compensation           -4mV\/Cell\/ C(to be cu