Is it possible to add an additional battery, and then use the same vent hose that came on the battery cover, by putting a tee in it with a small piece of hose? Also, what type of hose would you use? Need to add one for camping at a nascar event, and the additional battery will help cut the stand-alone generator use down to only when it is needed. Lighting on the battery system would be the drain on the batteries. Also, can a battery box that is used for a marine battery, be used if I can adapt the hose and its fitting to the top of the battery box?