Battery cells reset/rebalancing after erratic SoC readings

[Philip_1]

Once I reache

Thanks. After you reached 100%, did you leave the charger connected to the car for another 8 hours? And did you then disconnect and let the car sit locked and without app activity for a further period?

Once I reached the 100% I left it connected for about 6 hrs. Why... because "time to reach the target of 100%" changed 3 times during charging and the level although it was for example 90% dropped again to 73%! This way the car squeeze more energy to the battery bacause somehow learned that the true capacity is greater than the previous calculations!
Previous calculations occurs from constant charging 20%-80%.

When change was completed and 100% was steady in the instrument cluster I unplugged.
Then.. after just few minutes the level dropped 85% again..but there is no need to charge further to 100% again, if the actual kwh that you load to the battery are near to the spec 96kw.Step 6.

Note, I am not a Porsche expert, that's all as per my observation, but many Taycan owners followed this procedure once per year or something.

I am guessing that the random ghost drain I had sometimes it was related to this..I will check.

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[Cogs79]

Hi Folks, I am not sure if my issue is similar to what is described here, but I noticed in the last 2 months that I charge my car to 80%, I get the notification that it has charged to 80%, but when I get in the car, the display shows 78%, or this morning, 76%. It drops instantly as soon as the car starts up. Then it drops normally as I drive, without any jumps or anything. So it's just an instant drop of 2-4% despite charging to 80%.

I suspect it could be a temperature thing as we are getting large swings from -11 C to +7 in a day. But curious if this sounds similar.

Cogs

 

[EVowner]

Hi Folks, I am not sure if my issue is similar to what is described here, but I noticed in the last 2 months that I charge my car to 80%, I get the notification that it has charged to 80%, but when I get in the car, the display shows 78%, or this morning, 76%. It drops instantly as soon as the car starts up. Then it drops normally as I drive, without any jumps or anything. So it's just an instant drop of 2-4% despite charging to 80%.

I suspect it could be a temperature thing as we are getting large swings from -11 C to +7 in a day. But curious if this sounds similar.

Cogs

It is not temperature related. Have a look at https://www.macanevowners.com/forum...le-when-left-idle-for-a-week-or-longer.23481/
Mine was doing exactly same thing as you describe. Go to your service center and demand fix. Specifically ask for State of Health on your battery. Mine was 91% after 6 months/8k kms of light use. Diagnostic was also showing there is something wrong with HV system.

Car have spent more than a month at service center with them rebalancing battery multiple times. After all the rebalancing they claim State of Health is now at 100%. After driving it for 4 days it started discharging while stationary again. I am collecting evidence and monitoring the situation which is my advice to anybody who is having these issues. There seems to be something wrong with some of these cars and anybody who is claiming that this is normal or that it should be fixed by some "voodoo charging rituals" have no clue what they are talking about.

 

[Cogs79]

It is not temperature related. Have a look at https://www.macanevowners.com/forum...le-when-left-idle-for-a-week-or-longer.23481/
Mine was doing exactly same thing as you describe. Go to your service center and demand fix. Specifically ask for State of Health on your battery. Mine was 91% after 6 months/8k kms of light use. Diagnostic was also showing there is something wrong with HV system.

Car have spent more than a month at service center with them rebalancing battery multiple times. After all the rebalancing they claim State of Health is now at 100%. After driving it for 4 days it started discharging while stationary again. I am collecting evidence and monitoring the situation which is my advice to anybody who is having these issues. There seems to be something wrong with some of these cars and anybody who is claiming that this is normal or that it should be fixed by some "voodoo charging rituals" have no clue what they are talking about.

Thanks a lot for the details! My car remains plugged in while idle. This wasn't happening last year so it could be related to the last update. I am bringing in my car on Friday for the charge door replacement and summer tire swap, so I will definitely bring this up. I will ask about the SoH as well.

Edit: Forgot to mention that my Macan 4 just passed 7000km since Dec 2024, so it is pushing 1/2 the use as yours! And I only charge at home (7.2kW charger at home) and never DC charged it yet. It has lived a very gentle life so far!

 

[minsc]

Good morning all
Its mental that almost 100K new car ( macan 4s march 2025 when i bought it ) is doing this. In a bit of despair tbh. Was having readings like 30% battery charge, 30 miles range. Just got back from the dealership after a few days who said there was a bulletin and I should “charge/disharge the car 3 times” to rebalance the battery.

So in summary should I drain battery to < 10%, then charge to 100% ?

 

[Yves]

Good morning all
Its mental that almost 100K new car ( macan 4s march 2025 when i bought it ) is doing this. In a bit of despair tbh. Was having readings like 30% battery charge, 30 miles range. Just got back from the dealership after a few days who said there was a bulletin and I should “charge/disharge the car 3 times” to rebalance the battery.

So in summary should I drain battery to < 10%, then charge to 100% ?

From my Understanding it is best to drive the car below 5%, let it sit overnight, charge it to 95% let it sit overnight … rinse and repeat just to be sure …

 

[minsc]

From my Understanding it is best to drive the car below 5%, let it sit overnight, charge it to 95% let it sit overnight … rinse and repeat just to be sure …

Thanks Yves

 

[Fly4ever]

So in summary should I drain battery to < 10%, then charge to 100% ?

I did mine 2 months and almost 3.000Km ago and I don't have the slightest problem ever since.I believe that the more the battery is taken to its extremes (charging/recharging wise) the better.I managed to bring mine to as low as 4% and every time I was letting it overnight I was getting another 1-2% next morning.And when I charger to 100% and let it sit for a while there was space for another 10%. Judging by what others reported the procedure could be also be performed without reaching a full 100% charging but I wanted to give the maximum margin possible to my battery to rebalance its cells.

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