Features CN3791 12V 3A MPPT Solar Panel Controller 1 Cell Lithium Battery Charging with Super-Sized Aluminum Heat Sink 3.7V 31 * 49 mm / 1.2 * 1.9 Ounces Features: 1. High-end technology MPPT solar maximum power tracking charging management chip, with trickle, constant current, constant pressure charging management function. 2. Adopt imported high-frequency low-pass internal resistance double MOS tube, high-current diode, high-efficiency flat high-power inductance, Alloy current detection resistance 3. The base uses oversize aluminum heatsink to ensure long time stable operation of high current. 4. High-speed and efficient charging mode. 5. Dual status indicator, no battery when the red light flashing green light, charging when the red light is bright, full of self-stop at the same time green light.   Specification: Condition: 100% Brand New Model: CN3791 Input Voltage: 12V Output Voltage: Nominal 3.7V, Full Junction Voltage: 4.2V Charging Current: 3A Wiring Mode: Welding Weight: Approx. 12g / 0.4oz Size: Approx. 31 * 49mm / 1.2 * 1.9oz   Package List: 1 * Solar Panel Controller Charging Module Package List