function12

Do the newer batteries have the vent tubes? Do we need a battery with a vent tube connection?

Thundertub

Yes, my new battery came with a hard plastic vent tube that hooked right up to the tube on the car. It is a conventional acid/plates design (I chose not to experiment with Porsches new ultra light weight Lithium-ion battery for the GT3RS and Cayman R - at just over $2400 each...)

The purpose of the vent tube is to keep gases and fluids inside the battery from spilling onto the mounting plate and surrounding body/electricals.

If you choose an Optima or similar construction gel-type battery, there is nothing to spill out and those batteries do not have vent tubes. However, they do need a special mounting bracket (not included with the battery) for installation in a 996.

fpb111

Deka makes an AGM battery for our cars
Deka AGM batteries
Porsche 9AGM48

thirteeneast

Forget Lead Acid, they went out with square Wheels.

Gel the only way to go.

fpb111

thirteeneast,
Which non acid Gel batteries are available in London?

D.D.

So, after reading these postings, which interstate battery is the one for my 997 C4S? Is the MTP-91 correct on all counts? Or is it the H-7 or H-8 the best direct size/replacement?

Cefalu

I went with an Interstate H-7. Not lighter, but an exact size replacement fit. Interstate batteries are high quality and I have had very good luck with them. These cars have long battery cables and I did not want a marginal quality battery stressing the electrical system.

tgt40

Well time for me to replace mine this year, pleased with the life though, I don`t think it`s been replaced since new in 02. Going to try the H7 from Interstate. Thanks for the tips guys.

calbo

So today turned out to be my battery replacement day.
I narrowed the choice down to the Interstate MTP-H7 and the Duralast 94R-DLG.
I chose the Duralast primarily because it was about $30 cheaper.
The 94R-DLG does NOT have a vent drain outlet, but otherwise it is a near match to the OEM Moll battery. The bracket holds it in place firmly and the terminals reached the posts without stretching.

jmchris01

Just purchase and installed a new Interstate MTP-H7 battery for my 2000 911 C2, fit like a glove. Paid $149, searched all around, and on the internet. That was the best price I could find. Prices ranged from $149 - $189 throughout the Detroit-Metro area, for those who had them in stock.

DaveSpeed

OK I know this is an old thread but I need a battery for my 99 996. The one in the car is OEM and was purchased in 2005, so I believe it has lived a good life. So I called the dealer for a price and they said $200, and I thought why fool around to save 50-75 $ when the last OEM lasted a long time. Then he said plus $100 installation to reset the electronics?

Is this really a $100 installation, in all the threads I've read I saw nothing about resetting anything. If your telling me I have to reset my radio stations, so be it I can do that for free. I went to Autozone their price was $125.99 installed. But the tech had never installed on in a pcar and thought the dealer was just giving me a line. He is correct, just pull out the old one and put in a new one? Do you need the radio code to reset the radio? What am I missing?

RF5BPilot

For a 99, if you completely remove all current, you would need to reset the radio. But you can plug in a trickle charger while you replace the battery -- or even some of the small cell battery packs into the cigarette lighter to keep current in the system and not have to reset anything.

fpb111

There are three holes in the battery tray they fit:

H6 (48) MTP-H6 10-15/16 x 6-7/8 x 7-1/5 Top
H7 (94R) MTP-H7 12-3/8 x 6-7/8 x 7-1/5 Top
H8 (49) MTP-H8 13-15/16 x 6-7/8 x 7-1/5 Top

The first 2 holes are threaded, third hole is not. It is close to the edge of the tray and you need to supply your own nut and bolt for the clamp.

I replaced an Interstate MTP-H7 With a Braille 7548 AGM battery direct replacement.

Braille AGM B7548 battery group 48
BCI Group: [?]Group 48
Length:10.9" (277mm)
Width:6.8" (173mm)
Height (without posts):7.5" (191mm)

http://www.braillebattery.com/index....tteries/b7548#

Hurdigurdiman

WHAT ELECTRONICS? The radio code is the only setting that is needed on a 1999 C2 996. I have that car. I have had my battery off the car about 10 months ago as a dealer told me I needed a new battery when they had the car in for a long winded warranty transmission change. I went to Pep Boys and was exchanging same when the assistant asked me what was wrong with the one I had as it was only 2 years old. I had a Bosche with breather vent. I told him what my dealer had told me. The pep boys assistant told me the dealer was trying to rip me off and tested my old battery. Nothing wrong and taking the charge as expected. The assistant cancelled my would be sale as there was nothing wrong with the one I had. It's been on my DD since that date 10 months ago and never missed a trick. You can get your radio code from a site on the net when you put in your Vin Number. Thats what I had to do and the radio works every time. The Bosche was priced just over $100 at Pep Boys and thats where I will go when ever I need anything for my car. I love honesty and detest a rip off merchant. Needless to say that I will not be going back to that Porsche dealer in Lancaster PA. I will use Porsche of Reading PA for any work more than DIY.

logray

You certainly have to watch what the dealers do... 5 years ago on my cars PPI I was told the handbrake needed to be replaced because the dash light would not go on. What a rip.

Another trick is to just hook up a donor battery to the main leads using jumper cables (carefully). Then when you remove the battery there is no loss of power.