tk-porsche

I just drove the '19 Macan today after exactly 28 days of not driving it at all. I left it unlocked in the garage (hence, no alarm was active), and with no battery tender. It fired up right away and showed no signs whatsoever of having a weak battery. Hence, I can vouch for four weeks of no usage being not at all a problem with a relatively new battery (a bit over one year old). Same held true for a '14 BMW X1 with an older battery.

fsts2k

'18 Macan sat in the garage for three weeks, struggled to start and ran rough until car warmed up and I presume generate enough electricity to charge battery. Drove for a while and all is well.

For what it is worth, this is the second time my car has sat for three weeks and was near low on battery. I wouldn't suggest it is every Macan but 3 weeks is the limit for my GTS

tk-porsche

I am curious whether or not you had it locked? My suspicion is with the car locked and the alarm system running, it may be drawing quite a bit more current. I am guessing the battery age may also play somewhat of a role, mostly because of the highest crank power it's able to hold deteriorating over time.
Then again, the S is undoubted different from the base model in ways few of us will likely ever fully comprehend!

fsts2k

Thanks, not locked. No idea why it is drawing down so much. Could be battery age? It is the battery that was delivered with the car.

Maybe it just likes to be driven and gets depressed if it isn't started?

Need4S

I’ve been informed that locking the car actually causes less loss, as the car knows it’s not going to be driven so shuts down more systems. Notice how the fuel pump energizes the minute you open the driver’s door? All to make for less delay in getting in, sitting down and starting. The systems run in background longer when the car is not locked.

tk-porsche

Well, that's really an interesting piece of news. I'd have guessed the alarm sensors would be more of a power drain, but evidently not! Thanks for sharing that piece of information.

VintageRacer477

Our Mac started normally after sitting locked for a month. The 991 was on trickle charger overnight and did the same.

PCA1983

My personal rule is 3 days. If I think it will suit 3 days, or it has sat for 3 days, I put the tender on it.
This prevents sulfation. Sulfations over time kill batteries.

tk-porsche

Funny, the battery I had that lasted the longest (around 12 years) was in a car I drove only a few times a month and went a month or so at times undriven without any special care. I would think a lot would depend on how accessories drain the battery; in old cars, there was next to nothing that would draw current from the battery, excepting maybe maybe a clock.

gonracin'

Hopefully someone can help me with jump start issue. AAA sent someone to jump my 997.2 Turbo. Afterwards check engine light would not go off nor could it be cleared by dealer. Dealer sales person told me never to jump my 997.2. So does my indie tech. Luckily the indie shop saved me replacing the ECU. Since I can't imagine push starting even a manual is the only option to flatbed it to nearest AC plug and charge the batt.
I replaced the AC Delco that was new with an Optimus and since then all is good but I stilll worry about dead batt.
ANd of course the yahoo who placed the jumpers scratched the fender with his belt buckle.
Can someone explain why the 997 should not be jumped.

Thanks much

MrMarco

I would think three days is overkill, three or two weeks. Now my daily routinely sits for three days but I had a spare vehicle that would sit for a couple weeks maybe a month with no issues or early battery death. The last time I discovered a dead battery was in my Silverado after I left the dashcam plugged in over a cold night on an old battery...

jhbrennan

I seem to recall info in the Owner's Manual that addresses this - I don't remember any prohibition of using jumper cables. Look in your manual index under "emergency starting with jumper cables".and see if there's any info there.

wbferran

Which CTEK model is recommended? Thx

tk-porsche

I ended up getting this CTEK, which works great:

PCA1983

Most would think the same as you. Unless they have enough experience to know otherwise. I've had 12 Porsches and most say in the garage all week. So I learned. If you leave it sit for days most every week, you'll be lucky to get 3 years out of your batteries. The battery in my 944 died in 2 years of weekend use.
Since I started using a battery maintainer, my Porsche batteries have lasted more than 6 years, and I sold or traded b4 having to replace them. The battery in my 2017 991.2 911 Turbo is over 5 years old and still going strong. Sulfation is a common problem, if you care to research it. It's not much work to plug in my CTEK maintainer, so why wouldn't I? .