You can charge it from a wall outlet, car outlet, and solar panel. From an AC outlet, you can use 1200W to fully charge in only 1.6 hours. Using a car charging outlet will take approximately 13.5 hours to charge, while 400W solar input can top up DELTA in as fast as 3.5 hours (2×220W Solar Panels / 4×110W Solar Panels, two series, two parallel).