Solar Charger MPPT (3.7v LiPo)

This board provides solar power management, battery power support for single cell lithium batteries of 3.7v. Power regulation to 3.3v for microcontrollers is handled through onboard LDO. The battery is protected from overcharge and overdischarge. A voltage monitoring circuit is included to track battery levels which can be disabled to conserve standby power. This circuit is designed around low power devices to prolong deep sleep battery life.

This board was design for low power operations on battery power with the ability for solar recharging with MPPT control. Most onboard components have the option to be disabled or toggled for low power consumption. You should connect the battery when the charger is on that is why there is a switch to disable the solar when connecting a battery.

Calibrating MPPT

Attach the desired solar panel and put into direct sun. Then using a voltmeter measure the GND pin of the solar panel and the MPPT pad right above the MPPT potentiometer. Adjust the potentiometer to tune the MPPT control until you get a reading close to 1.205v. It is better to be above 1.205v than below it, otherwise charge cycles may not initialize in some conditions.

Board Specs

• Solar Power Support with MPPT Charge Circuit (28V 4A)
• Adjust MPPT with onboard potentiometer
• 3.7v LiPo Battery Power Support
• Screw Terminals for Battery and Power
• Onboard Battery Protection (Overdischarge & Overcurrent)
• Onboard Voltage Read Circuit (can be toggled off with EN)
• Use 2 pin jumper to connect EN to 3.3v to keep circuit always on
• Supports solar panels as low as 6V
• Charge and Done Indicator LEDs

Note: Supplying external 3.3V in does not charge battery and should not be connected.

$16

Price per unit