Km1.8t

I have an 06 Cayenne S with the Kessy system and usually leave my key fob in the car while parked in the Garage. I have been driving my daughters car for a week and went to drive the Cayenne today and the battery was dead. Battery is fairly new, no lights left on or other power source running. Car sat for around seven days and just would not turn over. Plugged in Charger and started up fine 30mins later.

Any thoughts that leaving key fob in car causing the battery draining?

gnat

Was the car locked?

I know on the 996s that the interior monitor is notorious for running the battery down if you leave it locked and don't drive it for a few weeks. Don't know if the Cayennes have the same affliction.

The answer for the 996s is to leave the car unlocked if it is an otherwise secure area.

I don't have any experience with the Kessy system, but in theory it would help run down your battery as it should be constantly scanning to see if the real key is in range. Maybe it acts differently if a key is in range vs if it's not and a key was (or wasn't) left too close to it?

Km1.8t

Car is not locked while parked in the Garage with the fob left on the console. I will keep the key inside for now and see if there is any change. May also get the battery checked just to make sure that is not the problem as well. I am sure I am not the only one that leaves their Key fob in the car while in a locked Garage.

Thanks for the response.

AGARubberDuck

There has been some discussion that simply leaving the cayenne unlocked for a period of time wears down the battery. In my own experience, this seems to be true. With Kessy working, it's really no big deal to hit the lock even when it is safe and sound in the garage; it unlocks again next time I reach for the handle.
It is counter intuitive though, as when you lock the car the interior monitor for the alarm is active.

RKD in OKC

Leave my 04 CS unlocked in the garage all the time with no issues. However, rarely go longer than a week without driving.

On my 01 Boxster S it also had the interior movement sensors. If you left it sitting locked for longer than a week the car would turn off looking for the remote and you had to unlock it with the key. Manual said it was a battery saving feature.

Km1.8t

RKD, do you leave fob in car when sitting in Garage?

TommyV

I've had my 08 CTT for about 6 months now. We went on vacation in early June and didn't drive it for about 9 days. Unlocked, in garage, key hanging 20 feet away in the house. Battery was new in February. Dead as a door nail. I had to trickle charge it several days in a row to get it up to snuff. I've noticed if I don't drive it for a few days, the battery seems a little weak. I will say that most of my driving is very short trips around town.

We are headed out of town again for about 9 days and I'm going to leave a battery tender jr. on it.

Maybe related, but while the battery appears fully charged, my battery tender jr. red light never turns green. It will turn green if I put it on the 911.

RKD in OKC

Yeppers, cars parked in garage, key fob in the cup holder in one, key in the ash tray of the other. 928 doesn't have a cup holder.

As a matter of fact, the past two weeks I've had one key fob in the cup holder and two key fobs in the bin between the seats. One is falling apart so I got a new one and haven't had a chance to go have the new one coded. Understand I have to have all the keys present to code the new key fob to the car because they have to re-code all key fobs to the car to add one. So tossed the extras in the stowage bin.

I haven't tried locking it and checking periodically to see when the "I'm Locked" light stops flashing. The one on my Boxster stopped after about a week and you had to use the key to unlock it. Kind of a hassle because I had one of those bumper plugs key hole plug.

RESP

Our 2012 Cayenne regularly sat for a week or as long as 3 weeks, unlocked in our garage.

Never had an issue with the battery draining.