CN3791 Solar Charge Controller Board 1 Cell Lithium Battery Charge Module This is a maximum power tracking (MPPT) solar charger for single-cell batteries. This MPPT solar charger you with the to the most possible power out of your solar panel or other photovoltaic device and into a rechargable battery. Set-up is easy as , just plug your solar panel into one side of the solar charger and your battery into the other and you are good to charging. Solar maximum power tracking (MPPT) is to that the light intensity change, photovoltaic cells output maximum power, to make full use of solar energy. Trickle charging of deeply discharged batteries. Automatic recharge, Battery overvoltage protection. Charge status and charge end status indication. Complete charge management for single-cell lithium batteries. The output of the Solar Charger is intended to charge a single polymer lithium cell. The load should be connected in parallel with the battery. Each Solar Charger comes equipped with a CN3791 power tracking battery charging circuit and -installed four 2-pin JST/PH2.0 connectors. Default we have set the holding voltage for MPPT. In general, need to use a switch mode DC - DC converter to realize MPPT function, keep the output voltage and charging current product maximize (output). Parameter: Input voltage: 6V Output voltage: nominal 3.7V full charge voltage 4.2V lithium battery Interface: 2-pin JST connectors (or PH2.0) Max Charging current: 2A PWM switching frequency: 300KHz Charging voltage: 4.2V +/- 1% Working environment temperature: -40 C to +85 C Size: 45 x 20 x 9.5mm Colour: Blue Material: PCB Package Contents: 1 x CN3791 MPPT solar panel regulator module 1x cable Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real . The measurement allowed error is +/- 1-3cm.