A useful project
A guy in my local Ham radio club built an extremely useful piece of kit-
It's a steel hand cart with about 75kg of sealed lead-acid batteries, a decent inverter, 20A or so of 5V USB ports, and Power Pole connectors for radios. Above the batteries there is space to store a few sq meters of solar panels. Naturally you can charge everything off of mains as well.
It takes up very little floor space standing upright in his garage, but is relatively easy to transport and move around. Large soft tires so one can move it across the ground.
That cart has helped quite a few people!