roccocaiazza

I have heard two different theories on battery drain during storage. If you store the car with the security system armed it helps save the battery as the car enters the sleep mode. The other theory is the security system actually drains the battery. Any thoughts?

Matt(inMA)

My understanding is the car will go into hibernation mode if the car is locked for a period of time. You can tell because you'll have to lift the door handle to enable the key to unlock the car.

If you are parking locally and have concerns about the battery you might consider putting it on a battery tender.


Matt

997.2GTS

The car definitely enters a hibernation mode when the alarm is armed. Measuring battery voltage showed a jump of .2+ volts (and increasing over each second to around a max of 12.8v) as soon as the vehicle was armed, so there is truth in that story. Leaving the vehicle disarmed results in a stable, lower 12.4 volts. This is on a 4 month old battery.

rileyracing1

997's will go into hibernation mode after a few days if the car is locked , as for battery drain on average, depending on the battery and climate in general any more than a month off the charger is a roll of the dice .
My old Bosh wet cell battery was good for about 5 or 6 weeks off the charger my new Odyssey AGM battery was off the trickle for 8 weeks and it started without any issue although my Bluetooth battery monitor did tell me the battery was starting to get on the lower side of 12V.

Either way any prolonged period of non use does require a battery tender also keep in mind a happy battery is a fully charged battery

DesmoSD

I believe our cars go into sleep mode after a week of sitting in idle. I just recently replaced mine and the Bosch battery that was in the car had a manufacture date of 2013. I bought the car in 2018 and not sure about the true battery life but I know for sure, I got 3 yrs out of it w/out any issues. I put an Interstate with a MY 5/21 so now I can track the battery life.

997.2GTS

It's possible they enter a deeper state of hibernation after time, but I clearly saw an immediate, significant charging difference between unlocked and locked/armed, so I think the battery saving benefit starts right when you lock.