I'm storing my 996TT for the winter so I will likely not drive it until end of March or April... I haven't driven it since the beginning of December. I'm noticing that my Interstate battery is getting weak (11.4V and dropping). Since I park the car in a secure garage complex, I don't have access to electricity for a battery maintainer. What can I do to try to preserve my battery?

1) start the car every week and let it idle for 10 minutes.
2) remove the battery from the car and trickle charge it at home.
3) replace the battery with a small utility battery, while I trickle charge the main battery at home.
4) just let the battery die and hope it comes back to life in April.
5) any other ideas.....

Thanks for your feedback

 

2 - Take the battery home. If you let it die, it will never come back. There is no value in having a battery in there if you are not using the car - Except for the security feature if you think you need that. Just make sure you know your radio code so you can reactivate when you put the battery back in.

 

+1. These cars drain the battery fast when not in use. Search around and you'll see several posts. I keep my car on a tender this time of year after every use because it could be a couple of weeks before driving it again. Since that isn't an option for you, remove the battery and charge it at home.

 

for the sake of the alarm system working i personally would never a leave a car without a battery. charge one and swap it with the another one.

 

What he said. Do leave it on bare ground (concrete) I suggest in your house on carpet, table, etc...

 

Do NOT leave it on bare ground (concrete)

 

#2 is probably the best option if you can keep on top of it and have a place to SAFELY charge your spare battery.

Although you could go with option 4 but don't count on the battery coming back. But, mostl batteries come with a 60 month or longer guarantee, so when it goes dead over the winter you can return it and they will hand you over a new battery in the spring. I think it is a free replacement for the first couple of years and then prorated after that till the end of the warrenty. Did that with my parents boat years ago and worked like a charm, just didn't tell them the details of how the battery was being used.

Lucky for me I live in California where I can drive the car year round. I have a battery tender I use for mine though when I know I'm not going to be driving it for extended periods.

 

Two Words: Battery Tender

$30.00 at ANYWHERE!

 

OP clearly stated in first post that garage does not have electricity and cannot use a battery tender.

 

You could bring the battery home to the tender?

The only problem with that method is if your car throws a fault code before you remove the battery. The code will clear when you remove the battery, but the fault will remain. When you start the car, your car could run with the fault for some time before a code comes up. Or worse, the fault could cause expensive damage without ever throwing a code!

That is why a Porsche shop/dealership has a special device that attaches to the car when they change batteries to keep the car from clearing the codes during the change.

The only other option is to drive the car periodically to prevent battery loss.

 

A [long winded, as usual] thought. My GT2 got some CS bits shortly after it was born. It didn't get the factory battery cut off. It is parked too much and always on a battery tender. So far this works well.

However, I also have an 01 BMW M Roadster. It is much easier to steal and these are considered very high theft risks. I set it up with a [hidden] quality battery cut off when it is stored [and every time I park it]. I realize that I have no "protection", but the battery remains fresh and the car never has any issues from not having everything memorized. I DO have the radio code for the rare times I use it.

Now the point: On the ROW GT2s you could specify a battery cut off from the Factory. However I have read in several sources that these cars don't like being without power as they lose various EMS memory settings and require readjusting and all when fired back up after a period of no power. It is stated that it could even result in having to tow the cars to the dealer to get the ECU functioning properly again. I understand the logic here BUT I don't understand how the Factory would install a cut off if it wasn't wise to use it.

As far as theft is concerned. Go guess! I spent a major portion of my working life in law enforcement and I am unconvinced that the security systems accomplish much except for discouraging a casual thief. Having security activate will trip the alarm and security features, yes. A good thief has a tow truck or suitable tools to get around much/most/all of this. Many thieves don't care if they tow it away with the alarm going. Usually they want to drive off in it. If they have the tools to bypass your security, they are gone. If there is NO battery they are going nowhere unless they are using a tow truck. Not many of them are going to bring/install a battery.

BTW, I have a hidden kill switch wired into every one of my play cars. There is NOTHING they hate more than sitting in a car with the engine cranking and no fire. I NEVER - EVER share the details of this with anyone - ever.

This situation isn't easily resolved and every option has an "issue".

Oh, you DO want to read your owners manual about what to do if you have the car locked up and without power, as everything back to normal can be complicated Your situation will likely put you in this situation so you want to know exactly what to do.

The fault code comment is noteworthy. Will faults show up on a dash read out when they first occur or only via Durametric?

Good luck
JR

 

Thanks everyone for all the advise.... This is a bit of a dilemma

I'm going to leave my Interstate battery in the car for awhile as I still have enough volts (11.4V) to do everything except start the car. Eventually, I will swap out the battery with a spare utility battery (just to maintain constant power) while I try to charge my Interstate battery. I'm concerned that leaving my car without a battery installed for an extended period of time will do damage. I'm not convinced of this, but I'm sure that it can't be good for the car.

In April, if my interstate battery is permanently damaged, I'll just replace it under my warranty (since it's only a couple of years old) and drive on.

Ironically, I have three trickle chargers (Battery Tender, Porsche battery maintainer, and solar powered) and a 200 ft extension cord but I still burn through batteries every couple of years!