THE FIELD BOX FROM HELL! aka The Ultimate Field box!
And here is the fuel cell! It has a nice, big cap for filling! If you look real close, you can see the white plug on the lower left corner. When you buy this container, it has a spigot that is supposed to hang over the edge of the shelf in the fridge so you can fill your water glass directly from it. I took the spigot off and cut a round disk of scrap PVC and screwed the cap over this to seal the spigot hole (hope that made sense!).
Astrohog