do i need to get a vented battery?
 

i need a new battery for this summer.

1991 C2 targa

the old battery had the plug on it for the aquarium tubing to attach to.

is this absolutely necessary?

what would happen if i just put in any cheap battery???

(car is only driven summers and stored in winter with the battery removed)

Welcome back, Planter. Good to see you around here again. :)

I think a regular battery would work just fine.

I don't agree. If the location is anything like earlier torsion bar cars, the battery will either:
- vent gasses inside the trunk area...very conveniently near the fuse box making all manner of copper connectors change to "green", or...
- an overcharged battery will spill acid in the battery tray area...very conveniently located right over the front suspension pivot should it rust through...

What's the big deal? Attach the clear tubing and vent to the outside. What? 1-2 dollars maybe? Or get a sealed Optima red top battery, or a smaller "Stinger" at a higher price.

---Wil Ferch

I't kind of tough to even find batteries with vents that you can hook the tubing up to anymore. When I needed to replace the battery in the C4 I used an Optima, which I don't believe vents like standard batteries and doesn't have liquid acid in the cells (I think that it is gelled). Pulled out the tubing and the plastic gas-trap reservoir, and never looked back.

Tom

the big deal is that i am having a hard time finding a battery with the vent attachment (on the battery). autozone only has only 1 available for a mercury Merkur and the attatchment is different.

also, i was trying to be a cheapskate...

i was thinking since the battery is only in there for about 5 months i could get away with a $29.00 walmart cheapy battery.

(i won't do it though if it would cause damage)

It's still 5 months of "operational risk"...if you're saying that the car is put away for the winter months.

I've gone to a number of battery places, and the "vent-nipple" type regular battery is easy to find if you broaden your search. Look for various brand names using a size 48/91 battery...and see if the vents collect to a small nipple you can then attach a $2 vent tube to...

Try first for Interstate....

---Wil

Hey planter:
I see you're in neighboring Amherst. Just go to Advance Auto Parts or such and you'll find this kind of battery. Just gotta look ! :)

--Wil

Is an 88 supposed to be vented? I have a vented battery but no hose to the outside and it dosen't look like there ever was (no gromets holes etc.).

Why get a battery that needs to be vented, buy a sealed (optima, hawker, odyssey) not cheap, but it will sove your venting prob.

OK...I guess I'm not clear enough...
- if you go with a "regular" battery...they either have 6 individual vent caps, or they have two vent "rectangles" that fit over 3 cells each. The battery then looks like it has two rectangular blocks of plastic on top next to one another. Each has 3 plugs on the bottom-side to cover the individual cells. This type of battery style *may* have a small 1/4" nipple on one end, or maybe not ( gotta look !). Get one that does. Then run a rubber hose from this to outside the car.
- sure...you can also go with a "sealed" battery, like a red top Optima gel type, and not worry about leaks or venting. Costs a bit more, though, like $105-$145 compared to about $75-$95 for a quality "regular" battery. The smaller, dry-cell type "stingers" cost even more...about $275 or so the last time I looked.
---Wil Ferch

Hint:run the hose to the front/bottom of the car...near where the front A/C fan is. If you look closely ( on cars up to 89)..there will be a row of rubber "flapper" plugs running from left to right ( across the car) along the bottom. The flapper style would, I guess, allow water accumulation to drain out. You can easilt fit a rubber hose "to the outside" through one of these ports.
---Wil

Wil,

If Planter's '91 C2 is like my '89 C4, then the battery vent "apparatus" will already be in place. It consists of a plastic tube, which runs to a small plastic reservior, which then vents through another small tube into the front left wing (fender). Also, on the 964's, the fuse box has been further removed from the battery: It is up against the firewall on the right (passenger) side, and it is now in a closed box with blade type fuses. Much more resistant to corrosion from any battery off-gassing.

Tom

Guys, thanks for the clarification, and of course...you're correct, the 964 pattern cars are different ( location/type of fuses, etc). It's still worth mentioning that on-board venting of any kind can't be good, and the detail I provided answered another poster's question on venting adn routing. In 89, you coulda' had either a 84-89 pattern torsion-bar Carrera...or the first of the coil spring 964's...true enough.
---Wil

I know I’m a little late on this thread but I just had to go through this myself lat week and am pretty happy with the solution I found. I had a genuine Porsche battery in there (group 48) that was about 4 years old. The PO got it from Rusnak for $127 according to my records. I left an interior light on for a couple of weeks and it killed the battery. I talked to my mechanic and he referred me to a local battery store. He explained that the Porsche battery is manufactured by Douglas and he had the exact same batteries directly from Douglas. He said that the factory delivery truck also drops them off at the BMW and Mercedes dealerships, where they put their stickers on. So I got one from him for $66. It looks completely identical to the one I had. I will have to connect up the vent line (mine did no have that either). The big advantage this battery had for me that it fits easily and has the little ridge on the bottom so I can secure it as was intended by the factory.