Taycan battery losing 5% per day when parked.

[writingpeter]

So here’s my story… Loving my 4S and no issues at all. Then I take it to Porsche for a recall (new heater) and PCM upgrade. Then off travelling for three weeks during which I (apparently foolishly) left it plugged in.

I come back to a dead 12v battery. RAC restarts the car and then all is fine. Except I realise the main battery charge is 63% and it was left at 85%. Weird.

I then monitor the car and realise that when not plugged into the charger and not in use it’s losing between 5 and 10% charge in a 24 hour period. Except sometimes it doesn’t. But mostly it does. I also notice that the car often seems to be heating the battery to 30C regardless of whether I’m driving it or not.

Porsche take a good look at the battery and upgrade the battery management software at the same time. They say one single cell looks suspiciously low. Perhaps the car is attempting to rebalance the cells, triggered by the dead 12v. They suggest I charge to 100 percent 3 or 4 times to help it reset. I’ve done that and each time it happily loses its charge without me driving it, and it continues to heat its battery to 30C. Porsche say the battery data is visible to them and they will continue to monitor its progress. But right now I can see the progress myself- I lose more charge parked than driving!

Anyone experienced this before?!

Sponsored

 

[chun]

In your app / car; in the pre-coditioning function; under timer, do you have remote climate control turned on?

That will heat/cool the cabin ever morning/ time you set up to a deperature between the range you defined (15-25 standard).

Assuming you park out in the sun, somwhere warm, that will drain the battery fast. Same if you live in Lapland with santa clause, warming up the cabin every morning will also drain the battery

I would suggest draining the car to 1-3%; and then slow charging it to 100% (11kw/h charging); if you do want to rebalance the battery as porsche told you. 1 time is enough. But the issue is not this.
If what i mentioned is not the case, than maybe try resetting the car to default settings and see how it behaves on default, and then slowly set up your things 1 by 1

 

[writingpeter]

The car is garaged at a nice 20C this time of year. No preconditioning on. The car has also been given a full reset by Porsche and software update. I’ve so far gone down to 16% and slow charged to 100% and also repeated a 100% charge four times. I’m thinking maybe it’s a battery fault with that cell they identified.

 

[daveo4EV]

Taycan losing 5% per day when parked

you mean depreciation?

 

[Redhot2474]

5

you mean depreciation?

5% depreciation is generous ?

 

[writingpeter]

Depreciation I understand. EV batteries? Black arts. No idea what’s going on.

 

[daveo4EV]

in all seriousness my 2020 Taycan showed _NO_ vampire load in the 4 years I owned it - losing this much power while parked is not common - and if it continues to happen will require dealer/service diagnosis - 5% battery is a LOT of power - it's either a fault with the battery or something is draining it - but I'm not sure what could be left running that would draw that much power.

5% a day is a very very high while parked
5% a week would stil concern me based on my observed behavior with my 2020
5% a month would be less concerning but still something out of the ordinatry
5% a quarter/3-months - I would be un-concerned

Tesla's can lose 3-6% overnight if you leave sentry mode on…but I might be out of date with my data - I had a co-worker with an early Model S - loved it - but he lived close to work and mostly walked - turns out in the 3-4 years he owned it he lost more to vampire load than he did driving it - ROFL - vampire load on Tesla's is "a thing" - but from my person experience and observing the Taycan forum it's not a thing for Taycan's - I welcome correction.

dealer/service visit is probably in your future if it continues and always happens.

 

[D00notD00d]

My understanding is that the overall State of Health is only as good as the least effective battery module\cell - according to a Porsche Newsroom article -
https://newsroom.porsche.com/en/202...h-voltage-battery-reparation-sales-26854.html
That implies that balancing occurs downwards.

You‘ve not said what the charging setting was while you left it plugged in for 3 weeks while you were away. The Porsche owners manual advice is that capacity of 20-50% should be maintained if the car is idle for more than 2 weeks. But I’ve not seen anything communicating that the battery warranty is invalidated if the care advice isn’t followed.

I’d suggest going back to your dealer and asking them to review if the battery warranty is being met. It seems that they already suspect a faulty cell. And if your car is subject to the potential battery module replacement recall.

Note dealers are not required to test battery health as part of the 111 point check they complete when selling a used Porsche, or during any scheduled service. Unless a fault occurs or you request it, a dealer will not check if the 3 year 80% residual capacity warranty term is met.

 

[laua]

Just an anecdotal data point - I have left my 4S at 75% for two weeks and it’s fine so far. I’m still able to see it on My Porsche app. Last year I left it for four weeks over the same period and it was fine. I did not plug it in both times.

 

[W1NGE]

So here’s my story… Loving my 4S and no issues at all. Then I take it to Porsche for a recall (new heater) and PCM upgrade. Then off travelling for three weeks during which I (apparently foolishly) left it plugged in.

I come back to a dead 12v battery. RAC restarts the car and then all is fine. Except I realise the main battery charge is 63% and it was left at 85%. Weird.

I then monitor the car and realise that when not plugged into the charger and not in use it’s losing between 5 and 10% charge in a 24 hour period. Except sometimes it doesn’t. But mostly it does. I also notice that the car often seems to be heating the battery to 30C regardless of whether I’m driving it or not.

Porsche take a good look at the battery and upgrade the battery management software at the same time. They say one single cell looks suspiciously low. Perhaps the car is attempting to rebalance the cells, triggered by the dead 12v. They suggest I charge to 100 percent 3 or 4 times to help it reset. I’ve done that and each time it happily loses its charge without me driving it, and it continues to heat its battery to 30C. Porsche say the battery data is visible to them and they will continue to monitor its progress. But right now I can see the progress myself- I lose more charge parked than driving!

Anyone experienced this before?!

100% abnormal.

Leaving your EVSE connected should not cause a problem or 12v battery drain. In the early days there was a software bug which addressed all known 12v issues. Porsche also recommended leaving your car connected when away for extended periods for trickle charging.

Feels like a duff cell issue unfortunately.

 

[BigBob]

So here’s my story… Loving my 4S and no issues at all. Then I take it to Porsche for a recall (new heater) and PCM upgrade. Then off travelling for three weeks during which I (apparently foolishly) left it plugged in.

I come back to a dead 12v battery. RAC restarts the car and then all is fine. Except I realise the main battery charge is 63% and it was left at 85%. Weird.

I then monitor the car and realise that when not plugged into the charger and not in use it’s losing between 5 and 10% charge in a 24 hour period. Except sometimes it doesn’t. But mostly it does. I also notice that the car often seems to be heating the battery to 30C regardless of whether I’m driving it or not.

Porsche take a good look at the battery and upgrade the battery management software at the same time. They say one single cell looks suspiciously low. Perhaps the car is attempting to rebalance the cells, triggered by the dead 12v. They suggest I charge to 100 percent 3 or 4 times to help it reset. I’ve done that and each time it happily loses its charge without me driving it, and it continues to heat its battery to 30C. Porsche say the battery data is visible to them and they will continue to monitor its progress. But right now I can see the progress myself- I lose more charge parked than driving!

Anyone experienced this before?!

Completely different to my experience. 2 weeks away recently, not sure my CT4S lost any charge at all. Wasn't plugged in, not that should matter.

Have they been able to replicate the problem in the workshop? Is so, at least that avoids the first layer of being batted off. How long do they want you to keep testing for to hope it goes away?

Sounds like they need to get their thick welly boots and gloves on and get tinkering with new battery bits, before it goes red circle of doom on you and leaves you stranded at an inopportune moment. And hopefully give you a decent loan vehicle.

Good luck.

 

[Singularity]

Taycan has a very low phantom drain, meaning it can be parked for weeks and the main battery will lose only a tiny bit of charge. If something else is happening, it is definitely not normal.

 

[writingpeter]

Yes thanks guys. It was my feeling too - this is not normal. The high voltage expert is on vacation (of course) but when he gets back I’ll see if I can get them to take a closer look. One interesting note from the diagnostics session last time: the technician said that Taycans send their battery data direct to Porsche. If a fault is recorded then a recall notice for that vehicle is automatically sent to the relevant Porsche Centre. They’ve had a few that way. So far that has not happened for my car… but they say they can monitor my battery health without me going to them.

The only visible sign I have of weird behaviour (other than the alarming drop in charge) is the car warming up its battery to 30C at various times regardless of me driving it or not. I wonder if that’s it trying to balance the bad cell and just draining itself instead.

 

[Tooney]

One interesting note from the diagnostics session last time: the technician said that Taycans send their battery data direct to Porsche. If a fault is recorded then a recall notice for that vehicle is automatically sent to the relevant Porsche Centre. They’ve had a few that way. So far that has not happened for my car… but they say they can monitor my battery health without me going to them.

It is true that Porsche can collect information from your Taycan. But this is true only if you have chosen/opted-in to allow Porsche access to vehicle service information.
In US, that permission can be reviewed in MyPorsche account. Below is clip from that setting:

If you have not allowed access to vehicle and service data, your battery data will not be shared with Porsche.
Even if you have allowed access to vehicle data, you should not rely on that system to identify problems with your HV battery. The dealer ought to thoroughly check it.

 

[Vim Schrotnock]

It sounds like you have a bad cell(s) for sure. 5%/day is ridiculously high no matter what car settings you have specified. As others here have said, you should be able to park the car at an airport garage and come back two weeks later to a battery that hasn't lost any significant charge. If this kind of battery drain were because of a user setting, it would be a terrible design, and we'd be hearing a lot more about it.

The battery drain while 'sitting' was what caused my dealer to finally recognize I had something wrong with my battery, and they discovered one (possibly two) bad cells. The only other indication I had was my range had dropped from 230 mi at 85% to 180 mi, and the dealer said this was within the 'normal' range. Once they saw the battery depletion of 3% over a couple days with the car just 'sitting', they went in and found the defective cells. I would insist the dealer check the battery cells.

Sponsored