I recently purchased my first Porsche, a 2005 Carrera S. It still has the original battery and I want to replace it. After reading several online comments, I am confused and concerned that I may be creating electrical/memory problems for myself by doing a simple disconnect and replace. Can anyone share the "preferred" way to do this exchange?

I would also appreciate recommendations of replacement batteries. I found that Interstate has a replacement at around $200 which is ok, but seems pricey compared to other replacement batteries I have purchased. All assistance would be greatly appreciated.

 

I have disconnected my battery numerous times to change steering wheel etc. When re-connected, you will see a PASM fault message, but after driving a few hundred feet and turning the car, it will reset itself and be fine.

I talked to a local Porsche shop yesterday, and they prefer Interstate batteries to all the rest, including Porsche batteries. The light weight ones are not as robust, so unless you're tracking, they recommended the Interstate (which I thought he said ran around $150).

 

Go with the Interstate MTP-H7 for around $120 as it's a perfect fit for the 997. Slightly lower CCA than the OEM battery but won't be a problem where you live.

I was also worried about issues if I replaced the battery myself so I had it done at an independent shop. The only code that came up was "low-voltage", which the mechanic cleared but probably would have gone away shortly anyway, he said.

I asked about issues with windows, radio, etc. and he said if you do the swap within a couple of minutes there shouldn't be any problems (and there weren't).

Same deal as with you - I just purchased an early build '06 a few weeks ago and the original battery seemed fine but the car had low miles so I didn't want to get stuck.

Hope this helps!

 

If you have some form of portable charger (w/cig light adapter), you may be able to plug it into there and keep a 12v current thru the system during the swap.

 

If you just replace the battery, without a 12volt cigarette source, you may need the dealer to to a "handover Procedure" to reactivate, seat heaters and a bunch of other options that will be decommissioned.

 

I'm not clear why disconnecting the battery is any different than replacing the battery? I have disconnected my battery lots of times, on 2 different cars, and have never had any issues when reconnecting, other than the PASM fault message which clears in minutes once the car is driven and taken through a corner.
I would never want a charger connected to the system via the cig. lighter when disconnecting and reconnecting the steering wheel airbag! That is why I disconnect the battery in the first place (I don't want any power on the system for that procedure).

 

I have an 06S with the original still working fine, but going to replace it in January with the Interstate MTP-H8 for about the $200 figure you have; way more CCA than I need but the car is perfect so it will probably be in the family for another 5+ years.

A couple of years ago I had a couple of low battery problems that were never solved but mysteriously went away. I do use a cigarette lighter Porsche battery tender (or go to batterytender.com) if the car is going to be parked for more than a couple of weeks. More important, one of the techs at Porsche NA told me to keep the car locked at night, etc., as this disables a # of the minor current draws.

 

I think the problem larrytk and I have had is when the battery slowly draws down and goes unchrged versus just disconnecting. I have disconnected several times w/o problems other than what you discussed.

When I let run down to all but dead I had the Seat heater and Garage door opener problem which needed to be reset by the dealer.

 

+1 on what he said..just did mine on a pre-emptive replacement. Consumer reports rate the Autozone batteries the best. I got the group 48-DL for $92.00...direct replacement

 

+1 on Autozone, But I went with the 49 which is slighlty longer. This requires using the last hole which does not have a welded nut so I had to slide an aircraft locking nut underneath the battery tray.

By the way the Autozone and Wal-Mart batteries are manufactured by the same company. Usually Wal-mart is cheaper.

Make sure on any Battery replacement that you reconnect the vent hose. Battery Acid would not be kind to your parts otherwise.

 

There is a great thread on this (do a search) that basically most of the cheap outlet batteries, Autozone, Walmart, Sam's etc. are made by the same manufacturer with slight different warranties, but drastically different prices.

 

The key is also age of battery on the shelf (mfgr dates are on the sides). I went with Autozone due to turnover. Agreed that Walmart is the same as Autozone but they might not be as fresh

 

NEVER do such silly thing. Cheap chargers may fry all your electronics if you decide to disconnect battery while charger is plugged into wall and connected to your internal car wiring.

Only way possible to do such trick if you have another battery connected to your car at swap time. But not a charger with impulse type power supply. What you probably had in mind was portable starter, not a charger, that has actual battery inside - this way you can do it. Just make sure it is not plugged in into 120V.

And there is no need at all to make it so complex - there is nothing wrong in disconnecting battery from 911 car. My car sleeps in garage right now with disconnected battery and piece of cloth thrown on top of trunk lock. When I have to drive it I simply connect it back. It does not hurt anything.

 

Thank you all for the immediate assistance. I feel much less intimidated about something that should be so easy to do.

I greatly appreciate the help!

 

Sorry. Meant to say use a 12V source during the quick swap, vs having any external cables in-the-way to juggle near your battery area in the process. (To avoid any accidental un-hook to gound....etc).