Deelow, i wish id heard your advice about dropping drills a few weeks ago, i only dropped mine off my workbench and it smapped in half. Transit, your plan sounds a bit complicated, especially as it sounds as though you only have two chargers to plug in. Just take the chargers inside with you, it will be just as quick as plugging your van in. I tend to overcomplicate things as well, best going for the simple option, even if it is boring. I was going to use a battery and a 12v cct to power my treehouse when i realised i could run a wire from my bedroom window straight into it and have as much power as i want