P85: Significant Capacity Loss and Vampire Drain

[Ben W]

In the weeks since the last software update (and a 12v battery replacement), my Signature P85 ('A' pack) has been behaving very oddly with respect to charging.

A month ago, it would standard-charge to about 222mi and range-charge to about 242mi. Now it standard-charges to just 202mi and range-charges to 222mi. It's also been experiencing ~20mi of vampire losses per day; I can charge the car to 202mi at 9pm, and by 9am the next morning it's at 192mi.

In the settings, Power Management -> 'Energy Saving' is ON, and 'Always Connected' is OFF. I'm not accessing the car remotely via any API's, and the car is not exposed to any extreme temperatures, so I can't think of what could be causing the drain.

I've just done a range charge (to 222mi) and will let the pack sit and balance for a while; hopefully that will help somewhat. I've also sent a note to Tesla Service, and will update when I hear back from them. Have any of you experienced anything like this?

 

[Larry Hutchinson]

That is nasty. I'd report to your service manager.

 

[msnow]

In the weeks since the last software update (and a 12v battery replacement), my Signature P85 ('A' pack) has been behaving very oddly with respect to charging.

A month ago, it would standard-charge to about 222mi and range-charge to about 242mi. Now it standard-charges to just 202mi and range-charges to 222mi. It's also been experiencing ~20mi of vampire losses per day; I can charge the car to 202mi at 9pm, and by 9am the next morning it's at 192mi.

In the settings, Power Management -> 'Energy Saving' is ON, and 'Always Connected' is OFF. I'm not accessing the car remotely via any API's, and the car is not exposed to any extreme temperatures, so I can't think of what could be causing the drain.

I've just done a range charge (to 222mi) and will let the pack sit and balance for a while; hopefully that will help somewhat. I've also sent a note to Tesla Service, and will update when I ahear back from them. Have any of you experienced anything like this?

No. I would think the balancing should fix it but if you are losing 20 rated miles in charging to 90% and 100% in the short time since you upgraded, either it's the software or the hardware (battery & battery management systems). The excessive vampire loss is further evidence of that. I wouldn't worry too much because both of those should be fixable by Tesla and since that sudden loss isn't normal you still have the battery warranty (that level of degradation in a day or two isn't normal).

 

[Ben W]

Well, balancing the battery seemed to help somewhat: I'm now able to reach 228mi on a Range charge and 205mi on a Standard charge. But these are still far below the 242mi/222mi I could achieve a month ago. And the vampire drain is still there, losing about 12 miles a day. Still waiting to hear back from the service center on this.

 

[tomas]

Not sure which 8.0 variant you have. I have the first one. My 2012 P85 A pack has not had any of this. I suspect an issue with 12v is causing issue.

Do you know exactly what range battery achieves at end of charge, or are the numbers you posted what you see in AM? If the latter, it could be charging to your old norm but then draining a bunch due to 12v problems.

 

[Ben W]

Not sure which 8.0 variant you have. I have the first one. My 2012 P85 A pack has not had any of this. I suspect an issue with 12v is causing issue.

Do you know exactly what range battery achieves at end of charge, or are the numbers you posted what you see in AM? If the latter, it could be charging to your old norm but then draining a bunch due to 12v problems.

Software is v8.0 (2.40.21). The range figures are from the moment charging stops. The vampire draw (I've seen 12-20mi/day) is about 150-250 watts continuous.

 

[AWDtsla]

How old is your 12V battery? I would bet it's because of excessive time with the HV contactors on trying to charge that thing.

 

[AWDtsla]

Force reboot everything, that may help too.

 

[shokunin]

What's the mileage on the pack. My '12 "A" pack still range charges to 260+ miles, daily 90% charge to 230+ miles. Did you ever have your pack's contactors changed?

 

[Ben W]

As I mentioned in my original post, the 12v battery was just replaced and is brand-new. The car has 45k miles on it, original 'A' battery, original contactors. Will try a force-reboot and see if that changes anything. Thanks for the suggestions!!

 

[MP3Mike]

As I mentioned in my original post, the 12v battery was just replaced and is brand-new.

While it may be brand new it might be defective. (But Tesla should easily be able to identify if that is the problem.)

 

[shokunin]

A while back I was experiencing high vampire losses 12-15 miles daily. Tesla proactively called to bring my car in to replace the original contactors as some were known to be problematic. Shortly after we had other Model S (2013) contactors replaced during routine service.

If they do have to replace the contactors, don't bring it into service with a full charge. I did, and they ran the heater on high with all the doors open to run the battery down.

My vampire losses were more inline with what others were experiencing after replacing the original contactors.

 

[mknox]

I have an early 2013 S85 (A-pack) with about 75,000 miles. My vampire drain has also gone up quite a bit. I have a dedicated sub-meter on my charging circuit, so I can see this quite well.

When the car was new(er), I would see it draw about 2.5 kWh every other day when the car was parked unattended (vacation, etc.). Now I see about 2.6 kWh every day under the same circumstances. That's about double.

In terms of % SOC, I have observed the car will lose 5% SOC for every 24 hours it sits. Usually when I come out in the morning, it will be 1 or 2% below the charging setpoint already.

I have played around and observe no noticeable difference with Energy Savings and Always Connected either ON or OFF, and I have the cabin heat protection feature turned off.

 

[AmpedRealtor]

Something is certainly wrong and I would contact service. I would suspect one or more failed battery modules.

 

[Ben W]

Force-reboot of both main screen and instrument cluster didn't help; the car has lost 5 rated miles in 8 hours since I did the reboot. Still waiting to hear back from the service center. Surprised; they're usually quicker than this. Will keep the thread updated.

 

[apacheguy]

Please inform us of the outcome. I am curious as well.

 

[Mike K]

As others have already mentioned, contact service. Vampire losses aside, that's too much range loss. I just sold my A pack 85 with 45,000 miles on it and it was 231/ 257 for 90% / range. You've lost 10%+ on a 45,000 mile car. Something is broken.

 

[Olle]

A friend had similar experience with sudden drop to 200 mile range. It was a HV battery fault, a broken battery module I think he said. Tesla service took care of it.

 

[mknox]

Something is certainly wrong and I would contact service. I would suspect one or more failed battery modules.

Thing is, my Range hasn't dropped at all. I do have an "Annual Service" coming up and this is something I want looked at.

 

[Ben W]

An update: my car eventually popped up a "Car Needs Service" warning, and Tesla remotely diagnosed it as a fault in the high-voltage battery pack (presumably a bad battery sheet), so they will give me a loaner battery pack and ship the original back to Fremont for "reconditioning", expected to take 4-6 weeks.

Since my original battery pack was the dreaded 'A'-type with a 90kW Supercharger limitation and other known issues, I am seriously hoping they will replace it with a newer-model pack (reconditioned or otherwise), rather than patching up the 'A'-pack. I did ask about the possibility of paying the difference to get a 90kWh or 100kWh pack, but it doesn't look like Tesla would offer me any deals there; I would have to pay full-price for the upgrade (~$27k), so it's eminently not worth it vs receiving a replacement 85kWh pack for free. If they had offered to swap in a reconditioned 90kWh pack instead of 85kWh for a $5k difference, say, or a new 100kWh pack for an extra $10k or even $15k, I would seriously consider it.