gacoffma

Replaced battery in the 991.2 with non-Porsche battery. I don't recall, did the Porsche battery have vents and a drain hose? The new battery has vents, should they be plugged or drain hose installed?

asellus

you'll want those fumes vented outside of that container, they are (potentially) flammable and (potentially) corrosive. can't speak to how the .2 battery setup is from the factory at this moment, I can check in a bit tho.

LSR

Is that battery an AGM? It should be. I’m no expert, but I’ve never seen a drain on an AGM. But they do have vents. Can you post brand and model of the battery?

Jack F

Photo of battery and vent ports would be helpful.

gacoffma

Yes, it's an Odessey AGM battery with vents. I meant to say a vent hose. I have since learned that they typically only have hose attached if they are located in a confined space such as boot or vehicle interior. No vent hose when located in the front.

asellus

Today I learned! (also whoops, never went to check mine, sorry)

LSR

As long as it’s an AGM intended for motor vehicle use you should be OK.

991_T

I just threw this in the car last saturday and don't remember seeing any vents on this particular Battery

asellus

It's pictured on the product page there. This little hole is a vent port. My e39 has a similar setup on either side of the battery -- small plastic hard L fitting that pushes into the hole on the battery, and the soft tube fits over the other side of the fitting to go downward out of the car.



The whole vent setup would look something like this, in the above case:

JW911

Strange, my 997 had a vent hose (non AGM). But my 991 original battery and Duracell AGM replacement did not have a vent hose.

cooky01

If it's an AGM battery in the frunk then no vent/vent hose is needed?
What if it's a traditional flooded (non-AGM) battery?

IXLR8

If the 991.2 is the same as a 991.1, the battery sits in an open area and not enclosed in the "sealed" trunk area. That is why you see so many batteries coated with "road dust". The factory installed Banner battery which is an AGM does not have/use a vent hose.

An AGM or GEL battery is a VRLA (Valve Regulated Lead Acid) type battery and they and ALL batteries must be vented for safety reasons but not necessarily with a hose. Now that does not mean they need to have a hose attached to them and vented to the outside unless they are in a sealed trunk.

On my 993 the conventional lead acid battery has a hose vented to the underside of the car and if I installed an AGM, it would need a vent hose as well because the battery sits in a sealed trunk.

Vents are either in all of the 6 battery caps or in the battery case. These days with manufacturer labels covering the caps and the top of the battery, they would need a vent in the battery case.


They usually have a push-in vented elbow and hose. If it is in an everyday car where the battery sits next to the engine under the hood, no vent hose is needed