Fafeicy Solar Module,1A 4.4-6.5V Input 4.2V Output LiPo Li-ion Lithium Battery Charger MPPT Solar Controller Module(Without Pin), Module

I've tried a number of different solar chargers with mixed results and none were very efficient, that is until this little gem. I've tested it in my same build as the others, 4 small solar panels that track the sun via arduino and two servos to charge two 18650 cells that power all the above and a meshtastic transceiver from RAKwireless. At sun up is reporting ~75-80% bat level and in one hour it's charged to 100%. None of the other charges I've tried could even come close to this.