1991 Jaguar XJ6 4.0L - Battery Venting

[GSCJR]

The vehicle comes equipped with a vent tube for the battery from the factory, but it was not connected, the elbow is missing, should I install one on the new replacement battery? I'm not a Jaguar expert and the battery is under the hood near the engine, why a factory vent? It's not as if the battery is in the trunk or in the passenger compartment.

The new replacement battery (Group 47), does have provisions for venting (2 openings, 1 on each side of the battery), but no elbow, so now what? Are those openings sealed unless an elbow is installed breaking an inner seal? Don't bother to vent at all? Vent one side and plug the other? I'm so confused; please help.

Thank you.

 

[BHopkins]

Where is the battery located? If it is in an open space (e.g., under the hood), then don't worry about venting it. If it is in a closed space (e.g., in the trunk, under the rear seat), then it is recommended to vent it to the outside.

If it is inside, you will probably find a hole in the floor, alongside one of the sides of the battery. The hole will be just the right size for small tubing. If this hole is present, it is a good confirmation that the battery should be vented.

 

[Carmudgeon]

Another factor -- is the new battery an AGM or standard flooded battery?

AGMs are sealed, and will only vent when something goes wrong, so it's not quite as vital to properly vent them like with a flooded battery, which generates gas in the normal course of charging.

 

[wings&wheels]

The batteries I've bought that have two vents included a plug for one. Hardware store hole plugs or a small wad of body caulk also works of you happen to misplace a plug... I'd get the elbow and reconnect the vent...it's there for a reason and JLR wouldn't have added the cost to the vehicle unless they thought it was necessary.

 

[GSCJR]

Another factor -- is the new battery an AGM or standard flooded battery?

Standard flooded battery.

 

[GSCJR]

AGMs are sealed, and will only vent when something goes wrong, so it's not quite as vital to properly vent them like with a flooded battery, which generates gas in the normal course of charging.

When I called the parts jobber to inquire why an elbow wasn't taped to, or in a baggie with the battery, he said that only AGM batteries come with the vent elbow; go figure.

 

[GSCJR]

After some more digging, I think I figured it out. Originally, the vehicle battery was enclosed in a box which was sealed off by the weather-stripping once the hood is shut. That original setup would require venting since the battery has nowhere to exhaust. Because that original battery box is no longer present, I don't believe that venting is required. Regardless, I'll install an elbow and plug the opposite port as @wings&wheels suggested, just to make it look complete.