So today, I received PCBs from OSHPark, wonderful quality as usual. I will be assembling one board this week to test using leftover SunLeaf components. Here are the boards:

After I assemble the board, the plan is to attempt to charge a lithium battery with a solar panel in the sun. To test I'm going to measure the charge on the battery before starting and measure it multiple times throughout the day. Stay tuned for more to follow.