My large AGM died last week. So, I do have a few sets of 6vdc golf cart batteries from Costco. I have been doing some research on potential solutions to bayonet battery vent caps. I was thinking of modifying standard vent caps, the ones with two holes, and making use of 90 degree drip system barbs. I did create a vent system that uses a small boat fuel ventilation port and a hose running to the internal battery box. This morning I was doing additional research on Flow-Rite battery vent caps . Centered around the RV2000 kit that is used for filling water to pairs of golf cart batteries. There was also the single manifold that is designed with the standard 2.7in bayonet vent caps. One question I had, if these systems are used for water distribution what happens to the outgoing gases? I do know that they have a built in spark protection. $45 for a set that will work with 2 golf cart batteries seems pretty steep. Any experience to share?