Perfect storage info from linderpat.

On the Battery Tender, that's the brand I use, but also have 1 CTek one that I plug into the center console socket plug of my wife's car. I use it in that one because she didn't have the quick connect pigtail installed, I needed an additional charger for hers anyway, so took the lazy way out and bought the CTek. Both brands work just fine. I have both Battery Tender Plus single chargers and their dual bank units (1 dual bank stays in the wakeboard boat to keep those dual batteries charged and the other is on a shelf near the lift for the car on the lift and the one under it in the winter). Keeping my Optima Red Top battery in my 914 always plugged into a BT when not being driven (doesn't see too much use - maybe 2,500-3,000 miles/year) had that battery last 12 years - just replaced it this fall with a new Yellow Top.

The Porsche charger is just a CTek with their name on it - no reason to pay the premium. There are different models with different features - just look through them on Amazon and pick the one with the features you like or go with the Battery Tender.

 

Battery tender here...

 

I just replaced this battery at the beginning of this past season, so don't want to have to do that again

 

Ctek 3300. You can find them for $50 shipped on ebay.
Will charge until full and then automatically trickle. Been using them for years. Get the cigarette lighter adaptor and its even more convenient.

 

 

The battery in a Porsche is really no different that the battery in a Corolla. 12 volts is 12 volts.
I use a generic tender. Same one that I used on my snowmobiles in the summer.

 

I just ordered a "Ctek 3300" with the cigarette lighter adapter. I see that "Ctek" has a mode for a AGM battery. Is a Porsche OEM battery AGM?

 

No, traditional lead acid, but it should say on the battery. If it has removable caps where you can add water, it's not AGM.

 

What you need to look for in a battery maintainer, or a smart maintainer.
I must have 1/2 dozen of these things. Ctec, battery tender, schumacker, energiser.
All work as designed. My spending threshold is 30-100 bucks.
I like the pigtail on the battery set up. Make sure it's fused.

 

OE battery on these cars is lead acid, so chances are that's what you've got. However, Porsche does make an AGM battery, so just look at it before you buy a charger. IIRC, the Battery Tender Plus is AGM-compatible. I think most of the Deltrans in Stores are Plus models. A non-plus would be pretty old stock.

 

 

Ummm, how would you keep a battery charged / tended without a power source?

I'd disconnect it, take it home and leave it on a tender, although if there's not a constant draw on it, like connected to a car that's not being used, maybe just disconnecting it is enough. In either scenario, MAKE SILURE YOU DO NOT LATCH THE FRUNK. Put an old T-shirt off to the side of the latch, but under the hood. This will let you latch it on the first click but not let it go all the way down and also remind you not to push it all the way down.

 

 

I've never had to code a battery to a car - I don't even know what that means as the battery connects to the cat and just supplies about 12v. How does the car know anything about the battery unless it has learned something like it's charging profile, CCAs available at a certain voltage number etc

I've never had a battery disconnected from my 997s for that long, but have probably disconnected them a dozen times for various reasons and I've never had to reset or retrain anything, not window positions, not keys, etc - maybe I've just been lucky.