MPPT 4.2V Lithium Battery Charging 12V Solar Panel Module - CN3791

An MPPT (Maximum Power Point Tracking) controller is far more advanced than a PWM controller as it enables the solar panel to operate at its maximum power point (the optimum voltage for maximum power output). It’s basically an efficient DC to DC converter used to optimize the power output of a solar system. Moreover, it has a charging current limiting function so that even if the input power of the solar panel exceeds the controller’s nominal rating, the controller can limit the charging current to keep it at the rated value.

The CN3791 MPPT solar charge controller module uses the CN3791 IC which’s a pulse width modulated switch-mode lithium-ion battery charge controller that can be powered by a photovoltaic cell with maximum power point tracking function. It’s specially tailored for charging lithium-ion batteries with constant current and constant voltage mode and adopts PWM step-down (buck) switching regulator architecture. The battery charge current can be set by a single external current sense resistor. Besides it features a dedicated MPPT pin to connect an external resistor divider for maximum power point tracking.

When charging the battery, priority is given to drawing energy from the solar panel. However, when the load draw current is greater than the charging current, it will also draw power from the battery. After all, if the input is not enough, the battery will slowly discharge. If the load is small, the battery will be charged.

Technical Data:

Solar panel input voltage: 12V
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
Dimensions：45 x 20 x 9.5 mm

The set includes 2x 2-pin JST cables.