Solar powered switch-mode charger (CN3801), protector (HY2112) and 5V booster (MT3608) for LiFePO4 batteries.
The charger provides maximum power point tracking (MPPT) and can easily be modified to work with LiPo batteries.
This charge controller board based on LT8490 MPPT chip can be modified to vary its charge characteristics. Doing so requires replacing resistors. Hence I needed a documented schematic and existing resisor values - the reason for reverse engineering the board.
Ebay listing for board:
Arduino-run board that performs MPPT functionality on a power input to maximize power production for solar panels, wind generators and TEGs, and then regulates to 18V.
Input: 1-120VDC @ up to about 100W (10A max current regardless of voltage)
Output: 18VDC @ up to 10A (max 180W)