Battery Drain Overnight?

[Paris92]

Yesterday the My Porsche app indicated my battery level was at 81%; as it has been for the last two weeks of non-use. Today the app indicates 68%. I am not at home so unable to check myself. Any ideas what would drain the battery that quickly in less than a day sitting idle?

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[M324]

I recognized the same (even though not that critical). My app indicated the battery was at 80% after charging but the next day I've entered the car it was at 77% and it lost one more % during the next 7hours. So, for me it lost 4% in total while being in the garage.

I can imagine two reasons:

1. The battery really loses percentage (which would not be good from my perspective)
2. What's shown in the app or the display in the car is not correct and in reality it has more capacity than displayed.

Interestingly this behavior just started recently. Before I could let the car stay in the garage for multiple days without losing one percent.

 

[nulled]

I’ve also started noticing some phantom drain recently — around 5–10%. In the past, I’ve left the car sitting idle for weeks without it losing even a single percent. On top of that, I recently had an issue where the battery seemed to be split in half, and the car wouldn’t charge above 30 kW on a 350 kW charger. Did Porsche push an OTA update that changed something?

 

[CHP]

I recognized the same (even though not that critical). My app indicated the battery was at 80% after charging but the next day I've entered the car it was at 77% and it lost one more % during the next 7hours. So, for me it lost 4% in total while being in the garage.

I can imagine two reasons:

1. The battery really loses percentage (which would not be good from my perspective)
2. What's shown in the app or the display in the car is not correct and in reality it has more capacity than displayed.

Interestingly this behavior just started recently. Before I could let the car stay in the garage for multiple days without losing one percent.

If this did not happen before in similar circumstances and assuming preconditioning & heating is off, something is draining the main battery. Would watch it a couple more days and if this continuous, I would reach out to dealer. Worst case scenario, rodent damage.

 

[chrisk]

I and several other members had the same issue after leaving the car sitting unplugged for a while. It is also accompanied with very slow DC charging. It appears as if the car loses access to some battery cells due to signiffiant cell voltage imbalance. More about my issue here https://www.macanevowners.com/forum/threads/very-slow-dc-charging.22212/ and post 13 has the solution for my case.
My speculation is that this particular scenario of the car sitting unplugged is not handled well by the BMS.

 

[ChrisFromUK]

Recently left mine in a car park for 14 days at 68% whilst on holiday and on return the battery was 55%.

When on the driveway and not used, it similarly seems to go down around 0.5% to 1% a day..

However, this isn't consistent as a few weeks ago it was on the driveway for 5 days and went from 59% to 63%.

Right now its Sunday and car last used on Friday. App says SoC is 34% which is what it was on Friday and if I go check the car ....... goes outside to check ..... it is 34%

So who knows what's going on.

 

[prime]

I’ve also noticed this. Recently I am getting significant phantom drain. I had 10% in 4 days while away from home. Before this I would have had maybe 1% loss if that.

 

[craz8]

I had exactly this same problem - 12 days of zero reported drain and a sudden 10%+ drop overnight - a few weeks ago whilst I was away. Mine was plugged into the charger during this time.

I have not DC charged in a while, so I don't know if that symptom is present

 

[RGBArgee]

Recently left mine in a car park for 14 days at 68% whilst on holiday and on return the battery was 55%.

When on the driveway and not used, it similarly seems to go down around 0.5% to 1% a day..

However, this isn't consistent as a few weeks ago it was on the driveway for 5 days and went from 59% to 63%.

Right now its Sunday and car last used on Friday. App says SoC is 34% which is what it was on Friday and if I go check the car ....... goes outside to check ..... it is 34%

So who knows what's going on.

Left my 4S in daughters garage for 3 weeks while we were away - 66% on leaving 66% on return - I was quite surprised to be fair!

 

[ChrisFromUK]

Left my 4S in daughters garage for 3 weeks while we were away - 66% on leaving 66% on return - I was quite surprised to be fair!

That's the way it's supposed to work. My wifes EV did that after 6 weeks but it's not a Porsche. Her car also lost nothing during our recent 2 week holiday whereas the Porsche lost 13%.

Mine uses 0.5% to 1% daily - but oddly not all of the time.

 

[RGBArgee]

That's the way it's supposed to work. My wifes EV did that after 6 weeks but it's not a Porsche. Her car also lost nothing during our recent 2 week holiday whereas the Porsche lost 13%.

Mine uses 0.5% to 1% daily - but oddly not all of the time.

Very odd - having ‘put up’ with 3 years of Taycan unreliability I was pleasantly surprised the 6 month old Macan 4S seems to be behaving still.

 

[El Bocko]

I hope you will forgive me asking, as I have not yet got a build slot , but when people get the battery drain; 1) do you have "Comfort Access"; 2) Are the keys near the vehicle; 3) do you keep the keys in a Faraday bag.
I am wondering if the car is being kept awake and alert by the presence of the keys or continual access by Porsche App?

 

[ChrisFromUK]

I hope you will forgive me asking, as I have not yet got a build slot , but when people get the battery drain; 1) do you have "Comfort Access"; 2) Are the keys near the vehicle; 3) do you keep the keys in a Faraday bag.
I am wondering if the car is being kept awake and alert by the presence of the keys or continual access by Porsche App?

1) Yes
2) Not particularly close
3) Yes - tried with and without, no difference

It's definitely not the key being close and communicating with the car and keeping it awake.

 

[M324]

No comfort access.

 

[ChrisFromUK]

Right now its Sunday and car last used on Friday. App says SoC is 34% which is what it was on Friday and if I go check the car ....... goes outside to check ..... it is 34%

So its Tuesday and just been out in the car (since Friday). When I got in, the SoC had dropped to 31%, down from 34% on Friday & still at that on Sunday.

Bonkers.

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