Nice post! I learned a lot from your post! Thanks very much! I recently bought a lithium portable power generator for energy storage when off the grid. They are pretty decent as they work with a 30W and a 60W solar panels. Also, with mega battery capacity of 500Wh / 137,700mAh, 300W pure sine wave output, the solar generator has Type-C Quick Charge, and 3 ways of recharging (solar / wall / car). It's far enough for daily uses when off the grid.