Here’s my latest creation. I wanted a heavy duty power tank but I’ve always struggle to find a suitable box. Most plastic boxes have the handle on the lid, so all of the weight of the box is held on what are usually quite flimsy plastic catches. Anyway, after some searching I found this box on eBay for £19.99. The handle is attached to the main body and is made of substantial aluminium tube:-
I’ve fitted an inverter, a double mains socket with 2 x 5V 2.4A USB outlets, and 3 x 12V outlets. I picked up a second hand battery for £20.
The box is pretty sturdy and I’m going to put a plywood board on the lid. It is then strong enough to stand/ sit on