Battery woes

[Cobnapint]

I'll set the scene, I retired earlier this year and knowing that I now would only be doing local journeys and wanting to avoid the trauma of a clogged DPF, I thought do the right thing and order yourself a brand new petrol MY23 Macan S and move the 2012 Cayenne Diesel on.
So I did, and in April I picked it up and I love it.

Fast forward to a week ago, I'm on a 2 mile journey (I know), warmish day, the outside temp sensor is stuck at 15 degC and the altitude sensor wasn't changing on gradients.

Mmmm. A couple of days later it's behaving itself - whatever, I'll mention it at the next service.

Yesterday, started it up after washing it (and starting was absolutely fine) and it's suddenly bombarding me with messages - Check front left DRL, Check front right DRL, Check left rear light, Check right rear light, Check High-Level brake light.
I'm like, oh dear, have I got a leak, has some water popped a fuse, or worse, a module?

I checked the brake lights and rear lights - all working, but the DRLs were not.

So multimeter out, checked all the fuses in the passenger end of the dash, all good.
Checked the drivers side, all good. Lifted the tailgate and checked all the ones behind the right hand trim piece in the boot, all good.
Put the cover back on, pressed the tailgate button to lower it, the tailgate stops 1 inch before completing and it's bleeping like there's something in the way - nothing in the way - wtf?
Tried it a few times after checking the small cluster of modules behind the right side boot trim piece, but after doing that the damn thing wouldn't drive up either!

Blood drains from face, beads of sweat on forehead, I'm thinking WHAT HAVE I DONE? It can't be the battery surely, it's only just under 4 months old FFS, and it's only done 1300 miles. I've heard stories of Macans eating batteries but nah, can't be, no way, too soon.

Tested the battery, 12.34V. Mmm. Last ditch attempt, I'll stick the CTEK on it overnight and cross everything in the morning.

Daybreak this morning and we have a nice green LED on the charger. Right, charger off, battery at 12.5V, bonnet down - alarm messages still there - gutted. I'll try one last thing, perhaps it needs a hard reset, so I accessed the battery in the boot, dissed the neg for one minute, reconnected it and - we have progress. Only one message is flashing up now, but the tailgate still isn't playing ball.
I pressed the button on the drivers door to raise it and it seemed to like it, it motored to the top and bleeped, but it still wouldn't motor down so I pushed it slowly down and when it got fully down it actually latched shut. Excellent. Then a quick drive up the road, the other alarm had cleared off and the DRLs are now working too. Bingo.

Conclusion: I knew Macans had a reputation for battery discharging but I didn't realise it was 'this' well earned. My battery is a Varta AGM 92Ah and was manufactured in Jan 23.
Ok, the blame partly lies with my short journey profile (the car has actually been on two 150 mile holidays though), but some of the blame must also lie with Porsche and the charging map they use (the batt, as you probably know, isn't always charging when the engine is running) which is nuts. It isn't going to save any recognisable fuel or save any measurable CO2 emissions, and for a car with such a high electrical load I think they need to look at it again.

[Cobnapint]

Said battery...

[MikeM]

If your pattern of use is infrequent ( i.e. not daily and short journeys ) your best practice would be to just connect your CTEK once a month and leave it on for a day or two as required. Have one car that’s rarely used so is permanently connected in garage. During the winter months will often have either my or my wife’s car on one if it looks like we are not going to use it for some time.

[Cobnapint]

It never used to be a problem years ago. The loads on car's batteries back then were tiny compared to now. It seems that the charging profiles have gone down as loads have gone up, and that's with so called low current LED lights.
Stop/start doesn't help of course.

[Col Lamb]

Do you have any items connected permanently to the car electrics (like a dashcam) or plugged into the OB2 data port?

[Cobnapint]

No, the dashcam is off an ignition controlled feed.

When you think about it the loads are quite large. The car lights up when you unlock it, the tailgate must take quite a bit of juice if you use it while parked up, the car is rammed with control modules and electronics, there's the DRLs etc, and when you park up the engine cooling fan runs for a while before shutting down.

[ScotMac]

No, the dashcam is off an ignition controlled feed.

When you think about it the loads are quite large. The car lights up when you unlock it, the tailgate must take quite a bit of juice if you use it while parked up, the car is rammed with control modules and electronics, there's the DRLs etc, and when you park up the engine cooling fan runs for a while before shutting down.

I have often thought this about a lot of "modern cars" - lots of lights (that remain on for ages), lots of motors and lots of fans (that often continue running for ages).

[Neil1911]

.....just under 4 months old FFS, and it's only done 1300 miles....

FFS, that's the issue, you nailed it! My MY23 S is just 5 months old but it's done 6,761 miles, not a warning light in sight, well, unless you include that annoying one that says it's time to refuel!

It's a bit of a hobby horse of mine but aren't you the perfect target market for an EV?

[Cobnapint]

Lol. Feels like I've got one considering the number of times I'm gonna have to charge the thing up.

[crockers]

Lol. Feels like I've got one considering the number of times I'm gonna have to charge the thing up.