Dead Battery for 2012 Cayman R

The battery on my CR cr*pped out today. Finally got the hood open to take a look, and the battery in my car is NOT the size that all the aftermarket battery sellers say fits my car. The battery is only 10 3/4" long, and has P/N 999.611.070.00. Searching for this hints that it is the same battery used in the GT3 , and I guess the 44 pound weight of this battery would be a good thing if I was tracking this car all the time. I'm looking for a better priced battery than what the dealer is offering. Looking at the Duralast Platinum H8- AGM as it's about half the price. Searching through here it seems that there is some disagreement about whether the H7 (94R) or the H8 is the right size. Will either work and is there a preference? Anyone have experience with the Duralast ? Thanks for any input.

Same thing happened to me a couple months ago- car all loaded up for the track at 6am Saturday and pfttt, battery dead. Jumped it and found the closest tire/ battery shop open at 7am. They had Interstate batteries and I got a "Mega-Tron plus" (had to chuckle at the name) size MTP 94R/ H7. It's a big brick but for my skills the weight isn't an issue. Can't remember the price but I didn't want to miss a track day to shop around. Oh, I did get an airbag light and had to get the dealer to clear it. No other problems so far.

The H8 is a bit bigger than the H7, and probably overkill for your car. The H8 also requires a nut to be manually placed under the mounting hole; the smaller H7 mounting location has a nut welded in place. Not a big deal, but just FYI. I'm sure Porsche uses the smaller, lighter battery in the R models as a weight saving measure.

Just curious - what has been your rule of thumb for length of time that ur CR sits b4 u put on your CTEK battery maintainer? And u know about using the Snowflake mode for AGM batteries , right? Or, is this car used almost every day, so u don't need to use a maintainer?

I use a Porsche maintainer - no snowflake mode. If the CR is going to sit more than 3-4 days I put it on the maintainer. Battery lasted a shade more than 4 years.

OK. U did the best u could. This is why batteries even have warranties. We had over 3000 flooded acid station battery sets, most rated 125 VDC (lots of 2 volt cells) with 20 year warranties. We had expensive charger/maintainers and monthly and periodic inspections and tests. Yet some batteries would crap out in a few years or 10 or 15, while many would go well beyond beyond 25 years. Such is the world of lead acid batteries.

I had to replace the battery in my CR two months ago. Went with an Interstate size H8 as a replacement. Details of my install including moving the mounting bracket are in an older thread. Search " battery replacement". Sent from my SM-G900P using Tapatalk

For just street use, the bigger battery is probably better. It will allow u to enjoy some music longer while cleaning and detailing ur car. And some reserve capacity is really handy once in a while.

Just to close this thread out, I ended up having my dealer replace the battery . Could have saved a few bucks doing it myself, but they gave me a significantly better price on the battery than what I could find it for at any of the nearby Interstate distributors and I just didn't want to hassle with it - plus they washed and detailed it! They did not use a Moll replacement - they put in an Interstate Mega-Tron Plus in an H6 size to match the Moll that came out (pretty sure this is the GT3 battery ). The Interstate fit exactly like the Moll and has a MUCH better warranty. On the positive side, I learned a lot out of this: a) how to get the key out of the ignition when the battery is dead; b) how to get the hood open when the battery is dead; c) if you don't push the red positive terminal in the fuse box all the way back in after opening the hood, you cannot jump start the car (user brain dead). All is good.

Resurrecting this old thread in hopes it might help others.... My CR battery died yesterday and was acting weird. Couldn't even jump start it using two different cars and a heavy duty charger. I was starting to think something was wrong with the car. No crank, just ticking despite trying to jump it and putting the battery on the charger overnight. Even with the charger on it, the voltage would only ready 10.5V to 11.8V or so. It never got up to 13 volts. Ended up buying a Walmart H6 battery - about $112. This is exactly the same size as the one that was in my car ( Porsche part number 999.611.070.00 Moll brand) from the factory, I presume. Installation was quick and easy and the + battery cover of the new battery has the vent plug for the side you aren't using. That little round plastic piece is removed to plug the vent tube on the driver-side of the car:

Does your 2012CR use an AGM battery , or the 'regular' battery ? My 2014 has an AGM from new, and I was just curious when they made the change.

Changed with 981 . I replaced my OEM with an AGM (2010). Works fine. I got one with higher cranking Amps and my Pioneer headunit no longer reboots each time I re-start the engine.