I'll see and raise here.
Running a car to charge the battery has to be the most inefficient method of fulfilling the goal. Waste's tons of gas. And if you don't run the car long enough (say, 10 minutes or more) you leave water in the exhaust system (it doesn't get hot enough to boil off). If you do let it run, you let the cats get very hot (they're not cooled by moving air) which is another bad thing.
A charger is the simplest, most efficient and kindest to the car. The other options (lifting the car), adding fuel additive are all things to do if you're leaving it for more than a month or two.
Also, very good point for the post citing the parking brake. Leave it off it you're storing the car. It will, in a damp climate, bond to the rotors.

 

What about locking vs leaving the car unlocked? I did a few searches and there were opinions both ways. Why would this have any effect on battery life?

 

As others have said, unless you really get the car up to operating temperature for a while, short on/off cycles build up moisture in the engine and increase corrosion.

Consider finding someone you trust with a clutch/6-speed and just have him/her drive the both of you for a country drive. You get out of the house. The car gets exercised. You know how the car is being driven. It will be good for the car. Everyone wins.

 

What is the reasoning on this - that the anit-theft monitoring system eats the battery? I reckon over a long time, that could be true, but with a maintainer, it shouldn't matter.

 

One afternoon, a mechanic at the local Porsche dealer made the point with a customer that the car uses less juice when locked. He said that unlocked, more systems stayed active, consuming more power--the battery runs down faster.

 

What he said

From 4 years plus, of using a battery maintainer, I can tell you that even after relatively long drives (over 100 miles), when I shut my Club Coupe down and connect the battery maintainer (the Porsche one made by c-tek), it charges for a time. That tells me the alternator cannot really keep up with the electrical demands the car has and fully charge the battery. And at idle my guess is the alternator certainly won't do better and is likely even less efficient at maintaining a full charge. While your battery won't go dead, when you consider all the variables, starting and running the car is an inefficient way to keep a battery charged and at the cost of "false economy".

Once you own a battery maintainer, it is so easy to use, that you can plug it in, any time you're parked at home. Literally, unless I will drive my Porsche the very next day, I just plug in the maintainer.

Your surgery gives you the "excuse" to get one, and as an added dividend with regular uses a battery maintainer can extend the life of your battery.

I'm on my 6th Porsche and my nearly 4 1/2 year old Club Coupe is the first that ever got out of warranty without a battery replacement. So I'm sold.

 

Last week when I started her up it sounded a little weak to me. A few days later.....dead battery......click, click, click. Porsche replaced the OEM battery under warranty, ($385.00) I then bought CTEK charger to keep new battery juiced. Now we're all happy!

 

just ordered a battery maintainer. it looks like the car is going to be parked for another 2 months or so from today now. ugggh.

suncoast - only $55!

thanks for your help everyone.

 

I'm glad your car was ready when you got back, but it is actually not a good idea to lift a car on jack stands for any extended period. The manual recommends against this. The shock rods can become corroded and I don't think it is good to unload the suspension and leave all that weight hanging unsupported for extended periods. You should just park it on cradles if you can't move it. Pump up the tires to 58 PSI (in the manual too) and park it on cradles or carpet runners.

Also, some have mentioned starting their cars during storage. The car should not be started as it creates condensation and drains the battery. Repeated cold starts are unnecessary and not good for the engine; they serve no purpose. The old rumor of starting an engine so that the cylinders and other internal engine parts can be lubricated is just that -a rumor- and an untrue one.

Get a trickle charger, park it on cradles/carpet runners and leave it alone. Even fuel stabilizer is unnecessary unless the car is stored for several months. Fuel stabilizer does reduce the octane level of gasoline so the tank should be refilled asap once returned to use.

 

As someone said, it isn't a good idea to use the engine at idle to charge the battery. The engine never gets hot, so condensation builds up internally which can be acidic and make problems with internals. Also, I put a couple desiccant packs on the floor mats to keep the interior surfaces at the proper moisture level. Keep the windows up too.