battery venting question please...

[mac73s]

I purchased (2) U-911 Interstate batteries for the 73S that have side vent openings on each side of the battery. My intent - assuming venting is still a recommended course of action - will be to plug one side and vent the other with a 90 degree fitting and route the vent house outside the box. Re the attached photo, can I assume the hole on the front side of the battery box is indeed where the vent tube should be routed, and also, what is the purpose of the larger hole on top of the box? Thank you!

[jrbennett]

I'm not sure if there is actually a hole to run the vent line through. Either of those holes should work however I think they are for mounting the TTG driving/fog lamp mounts.
I recently replaced the batteries in one of my '73Ts and had planned to add a vent, just never got around to it.

[Sepia911S]

My 73S has Interstate batteries. The 911 always had Porsche batteries and Jim used aquarium tubing to vent the batteries. He didn't like the original tubing because it was too short. I will take and post some photographs. I won't get it done until Monday afternoon though.

[mac73s]

Candyce....thank you for taking the time to take a few photos...as always, you're most generous with your information and sharing photos of the great original exemplar your 'S' is.

My 73S has Interstate batteries. The 911 always had Porsche batteries and Jim used aquarium tubing to vent the batteries. He didn't like the original tubing because it was too short. I will take and post some photographs. I won't get it done until Monday afternoon though.

[Richardnew]

I just put 2 new batteries in my car as well. My car is currently at a restoration shop and the owner was talking about how these tubes make a huge difference in keeping the battery boxes intact. My left side battery is fine. The tubing actually runs down below the pan. Now I just have to figure out the right side.

Richard Newton

[Sepia911S]

The aquarium tubing has been on the batteries as long as I can remember. The tubing is not original to the car. At the first three parades I participated in, there was always a negative comment about the tubes. At Traverse City, I just pulled them off, on Ed Mayo's advice, and put them back on. When Larry Marzano inspected the car, he removed the batteries and added the black "things" on the bottom of the hose. In these photographs, the hose comes off the left side of the battery and winds below the black canister

The car was always just a summer driver. The battery box is in good condition because every winter Jim removed the batteries.

[beh911]

Run the vent tubing out the front on each side by removing one of the body plugs behind the front bumper. The holes in the above pics are for the TTG light brackets. If you don't have the lights on your car I would be sure to plug these up.

Edit: Candyce posted at same time I did! I went a slightly different routethan here and put the vent tubes in my car through these openings on either side...

[Sepia911S]

On the passenger side, the tubing is tucked underneath the battery.

[RSTarga]

The battery drain tubes should not go through your trunk floor drains, if any water enters the trunk, it has nowhere to go. Candyce has good trunk seals , so not a problem, but not correct routing.

[fromage]

why use old technology wet cell batteries ? Wet cells are OK while new, but once they start declining their gassing goes up as they age... first sign of aging and increased gassing is the need to add water from the first time onward... Gel or AGM batteries are sealed, which makes them a better choice, with almost nil corrosion from gassing... short of wanting period correct batteries for the last point in a major concurs event there is no real reason to use a wet cell battery... let me walk that back a bit... AGM batteries do not tolerate being left in a discharged state for any length of time, causing them to fail prematurely if ignored and left to discharge... when using an AGM, a battery tender and exercise will keep the battery in top shape... no gassing, no vent lines, no corrosion, no maintainance