What's this for?

[dcboxster]

Chaps,

Whilst installing an alpine sub this afternoon in my '99 996 C2 CAB I came across the following clear tube located close to my battery. One end of the tube is open and looks like it should be connected to something, where the other seems to dissappear into the top of the front right hand wheel arch.

Any ideas on what it is for?/where it should be connected?

Many thanks,

Dave (dcboxster)

[eshuber]

That looks like the vent tube for the battery - on my stock battery , it attaches in the center closest to the bulkhead.

Ed

[dcboxster]

That looks like the vent tube for the battery - on my stock battery , it attaches in the center closest to the bulkhead.

Ed

Thanks Ed, That makes sense, as the battery was replaced about 14 months ago just before I purchased the car. No doubt my new battery doesn't need it? I'll have a good check anyway.

Many thanks, again.

Dave

[Loren]

No doubt my new battery doesn't need it?

Then you likely have the wrong type of battery.

All batteries vent gases (acid gas). Since this is inside your trunk area you really want a battery with an external vent connection (and that tube connected).

http://www.renntech.org/forums/index.php?s...ost&p=14446

[Tool Pants]

Don't know what the replacement aftermarket batteries sold in the UK look like.

That looks like a Moll style battery that has the vent provision on either side of the battery. I can see it in your picture. There should be a plug where the yellow arrow is for the vent. On the opposite side there should be another plug. That is so you can vent the battery from either side, if needed, and depending on the vehicle application.

Take some more pictures and see if you can find the brand.

With the Moll you remove a plug on the side and press in this adapter that connects to the clear plastic vent tube.

[dcboxster]

Don't know what the replacement aftermarket batteries sold in the UK look like.

That looks like a Moll style battery that has the vent provision on either side of the battery. I can see it in your picture. There should be a plug where the yellow arrow is for the vent. On the opposite side there should be another plug. That is so you can vent the battery from either side, if needed, and depending on the vehicle application.

Take some more pictures and see if you can find the brand.

With the Moll you remove a plug on the side and press in this adapter that connects to the clear plastic vent tube.

Thanks Loren/Toolpants. I'll take some more photos tonight and look for the brand name.

[99C2_Riyanto]

No doubt my new battery doesn't need it?

Then you likely have the wrong type of battery.

All batteries vent gases (acid gas). Since this is inside your trunk area you really want a battery with an external vent connection (and that tube connected).

http://www.renntech.org/forums/index.php?s...ost&p=14446

I cannot find the vent hole for Interstate MTP-91 - Mega-Tron Plus. http://www.interstatebatteries.com/estore/...nk%7C1&js=1

I have used the battery for 2 months. Am I asking for trouble for continuing to use it?

[Loren]

No doubt my new battery doesn't need it?

Then you likely have the wrong type of battery.

All batteries vent gases (acid gas). Since this is inside your trunk area you really want a battery with an external vent connection (and that tube connected).

http://www.renntech.org/forums/index.php?s...ost&p=14446

I cannot find the vent hole for Interstate MTP-91 - Mega-Tron Plus. http://www.interstatebatteries.com/estore/...nk%7C1&js=1

I have used the battery for 2 months. Am I asking for trouble for continuing to use it?

It is right in the center - just like the others. It is that small oval opening. You will need to get the short tube that fits the oval and connect it to your clear tube.

I think all of these batteries seem to be made by Johnson Controls.

[Tool Pants]

This is that Interstate, still in the plastic. My finger is on the vent.

You need the vent tube adapter that you see in the plastic bag.

[99C2_Riyanto]

Wow Tool Pants. That is very impressive! How did you get a picture to answer exactly my question in under an hour? :clapping:

Never mind, you don't need to tell me. Just want to say I'm impressed :cheers:

[Tool Pants]

I took that picture last week at a tech session at a local Porsche shop. I always wondered why some people with Interstate batteries were not geting the vent tube. Johnson Controls makes the Interstate and other brands. The Johnson other brands we use have the vent tube in a plastic bag attached to the battery. For some reason Johnson Controls does not attach the plastic bag to the battery with the Interstate brand sold to shops. So you have to ask for it.

[wwest]

There are fairly common instances wherein a non-vented battery can be EXTREMELY DANGEROUS, especially where this one is located.

It is not altogether unusual for the voltage regulator to fail in a way that results in SEVERE over-charging of the battery, so much so that the battery electrolyte begins to boil and vent gas. Gasses not only hazardous if you breath them but also EXPLOSIVE. Even more common might be a shorted cell within the battery in which case the regulator tries to charge the 5 remaining 2.25 volt cells to a full ~13 volts.

So...

Be sure, absolutely SURE, your battery is vented.