We use a Rigid tool case from home depot. Take the top liner out, use pegboard to mount 6 vex chargers and power strip. Bottom bins used to hold batteries and AAA chargers… Plenty of room for extension cord.
We have two cases like this, as does our High School and QCC2 Blue Rooster. It works very well for us. No need for cooling system.
My team did something last year for our regional and state competitions where we took a piece of peg board and duct taped a strip of chargers to the board, zip tied down all the cables and our power strip (we actually had two), as well as the AAA charger. The only downside was that it was somewhat inefficient with the amount of space it used, however it saved a lot of time as far as getting it all set up and organized.
My team uses a sheet of plywood covered in felt. We drilled holes in the plywood and zip tied the chargers to the board. It’s easily expandable to 10 chargers; our first one had 8 7.2V chargers and 4 AAA battery chargers. We also have smaller ones that fit on top and inside of a Pelican 350 case. They hold 4 7.2V chargers and 1 AAA battery charger each. To add a handle, just cut out a hole for your hand in the plywood.