My ‘09 CTTS doesn’t like being left “sleeping” in the garage very long before its battery doesn’t have enough juice to start. 25-days or more and it’s questionable whether it needs a jump.


I bought the car used three years ago so I’m not sure if the battery is original. However, I’m curious what others experience before this happens. Is three to four weeks about the norm? I have three Porsche's, so I know they suck power like crazy just sitting in the garage. Do I need a new battery?

 

I really don't know the life of the battery when it just sits. If I know I am not going to drive for an extended period I disconnect the negative terminal. I do this especially when on vacation, as there is nothing worse than coming back from a tropical vacation and trying to start the car at -20 and the battery has drained and need a jump in one of those huge airport parking lots.

 

Mine only lasted about week and a half and I had to jump

 

You need a "battery tender" they are 25 bucks.
Hook it up when your not driving if its going to sit that long. They say all the control units and stuff have a non volatile memory but strange stuff seems to happen. Kinda like when you run your phone all the way down to 1 or 2 % over and over.

 

Batteries will self discharge even if not connected and it is not good for them. A battery tender is the solution. There are plug in models and solar powered ones. There is a nice Porsche approved one you can get without the Porsche label for a reasonable price. I think it's the CTEK for $50something. They say it can even help bring back a sulphated battery. Check it out...

 

I'll check it out

 

All newer cars have this flaw, with the amount of electronics running at all times the batteries will slowly drain overtime. Add some cold to the mixture and they drain even faster.

I use a Schumacher 1.5a trickle charger/battery maintainer ($20 from amazon) and it does the trick for my cars.

Model: Schumacher SEM-1562A-CA

Ofcourse, if your battery is still the original factory one and it's past 4 years, your battery may be going as well.

On my 1985 Bitter SC, I haven't replaced the battery in over 15 years using a maintainer.

 

No issues here on any current or past Porsches. You should be able to leave it alone for months without issue. If you've had it for 3 years and don't know how old the battery is - you probably need a new battery. It's pretty simple to have it tested and see if it's strong.