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12V battery problem at 173 miles in

Discussion in 'Model S: Battery & Charging' started by docrice, Oct 11, 2014.

  1. docrice

    docrice Member

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    #1 docrice, Oct 11, 2014
    Last edited: Oct 12, 2014
    tl;dr - S85, took delivery 9/30 with 9 miles on the odometer, less than 2 weeks later at 173 miles in I got a 12V battery warning on the freeway, towed to service center, got a loaner. Seems like record time from new car to first problem.


    Longer version:

    I'm currently at less than a single full-charge of driving distance with a brand-new car and I already got the "12V Battery Power Low - Car May Shut Down Unexpectedly" message. This happened on 101 N in Santa Clara, CA (right before the Lawrence Expressway exit) but was able to pull over to the shoulder. How disappointing. Immediately called Tesla Roadside Assistance and went through a reboot and when that didn't work, a momentary power-off. When those attempts failed, a flatbed service was called.

    Interestingly, after the tow service was called the battery warning disappeared and I was able to put the car into Drive. I decided to play it safe and let the service center take a look at it, but it was nice to be able to run AC while I waited for the tow since it was rather warm inside the car.

    The tow truck arrived roughly half an hour after Roadside Assistance contacted them. I engaged the tow mode and it was interesting to watch my car pulled onto the flatbed. A short ride later, I was at the Sunnyvale service center moving my belongings to a loaner which is an S85 similar to mine but in black / tan (a combination I was originally considering). It had almost 900 miles but was probably built right before the Autopilot hardware became standard. I already miss the Driver Assist features.

    Overall, the roadside and service center experience was relatively seamless and while inconvenient as I was on the way to work, I didn't expect the transition from a dead car to a loaner to be this easy.

    But before Tesla's blamed for a defective 12V battery, this may be owner negligence. When I first took delivery with a charge level of 235 miles, I had a detailer appointment scheduled on the same day but he was running about a week behind so the delivery center allowed me to keep the car at the factory for 6 days (sitting outside along the other demo cars). It wasn't charged at all during this time. I also stopped by several evenings and remotely opened the car with my phone so I could familiarize myself with the controls, pair the phone, configure settings, listen to the radio, etc.. The car wasn't running 6.0 yet so I couldn't roll it over to the Supercharger stalls.

    Later I finally got to drive it a few blocks to the detailing shop and there it stayed for a few days. I finally picked it up 10/9 with about 170 miles on the main battery meter and made my first charge at the factory Supercharger. Since then I've maintained the charge at home, used a Chargepoint near my office, and also used the factory Supercharger again last night.

    I guess sitting in the car at night during the first week and powering the dashboard electronics without the car being plugged in created this seemingly-premature 12V battery failure. I did hang out in the car for an hour or so at a time since it was fun. It's fortunate that I was able to get a loaner for the weekend.
     
  2. GSP

    GSP Member

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    I doubt this was due to your use or lack of charging for a few days. The high voltage battery should keep the 12 V topped off (using the DC-DC converter).

    Please keep us informed about what the service center finds out.

    GSP
     
  3. steve841

    steve841 Active Member

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    Said it before (as I have had numerous 12v batteries replaced) and I'll say it again ... It amazes me that 20th century technology is the Achilles heel of the Model S.
     
  4. jerry33

    jerry33 S85 - VIN:P05130 - 3/2/13

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    I thought this too, but Tesla did try no-12V in the first Roadsters and had a lot of problems, so they went back to the 12V battery. The problem is, as I understand it, that the DC-DC converter has a problem keeping the voltage steady (at least for a reasonable cost) and a 12V battery provides this stability. In addition, certain safety features need to be active--at least for a few minutes--when the traction battery is disconnected. It also makes traction battery replacement easier as the computers stay powered up, so a secondary electrical source of some kind is required, and the 12V battery seems to be the most cost effective solution. Perhaps redundant 12V batteries that are easily replaceable would be the ultimate solution as it would be unlikely that both would fail at the same time.
     
  5. ToddRLockwood

    ToddRLockwood Active Member

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    I'm not absolutely sure that this is correct. The car may have to be either plugged in or turned on for the 12V charging to occur.
     
  6. Todd Burch

    Todd Burch Electron Pilot

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    GSP is correct. The car will wake itself up as necessary to top off the 12V even if asleep and unplugged.
     
  7. docrice

    docrice Member

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    Thanks for the comments. Interestingly enough, my loaner had a "Car needs service" notice at the top of the center screen this afternoon when I walked into the garage and the screens were frozen. Had to reboot both screens to get the car working again. I hope I'm not a bad omen.

    The only commonality that I can think of is my charging setup at home (110V) and the UMC is plugged into a power strip. My brain was on autopilot when I connected it to that instead of directly into the socket. I figure the onboard charging system shouldn't be affected though enough to cause this kind of an issue.
     
  8. v12 to 12v

    v12 to 12v Active Member

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    I had 2 new batteries in the first 10 months of ownership. It has now been one year and three month's since my last replacement. I think that with the software changes and the change of the battery type used, the problem has been resolved.

    With my battery changes, Tesla has always contacted me for a pre-emptive battery change before I had trouble. I don't understand how someone could get caught with all the updates and monitoring that is in place today.
     
  9. docrice

    docrice Member

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    I finally got my S85 back today. It sounds funny, but I've driven the loaner more miles than I have my own car.

    Given that this problem occurred with such low mileage, this case apparently had high visibility with their engineering team and the vehicle was moved back to the factory. I woke up Monday and saw via the phone app that it was sitting back at the Fremont service center. Determining root cause would apparently take a while and since they wanted to get the car back into my hands as quickly as possible, they swapped out not only the 12V for diagnosis but also the main battery pack. Unfortunately, the service manager indicated to me that they might not be able to relay back to me any findings about root cause(s) if the information involves proprietary elements of the system, although understandable.

    The odometer read 180 miles when I got it back. The folks at the factory test drove it a few miles, and the service center in Sunnyvale drove it a few miles. They were very accommodating to my schedule and trucked the car over to my office at my convenience. They were really willing to make me happy and go the distance.

    I suspect that if this had been any other car manufacturer, the customer service would have been much less stellar and the experience more time-consuming of an ordeal. Obviously Tesla's still trying to earn a reputation so they have incentive to make the effort. Maybe the main office has staff proactively monitoring these forums for complaints. I'm just glad they were able to provide me with an S85 loaner (probably built in the last couple of months, didn't have the Autopilot hardware, no sunroof, no parking sensors). It's hard to go back to a conventional vehicle once you've had some time in the iPhone of cars.

    A little off-topic: last Thursday when I picked up my car at the detailer, the paint was immaculate. I paid a very pretty penny for defect correction (to eliminate swirls and marring that came straight from the factory). When I got it back today, there were swirl marks, marring, and fingerprint smudges. When the car was trucked to the service center on Saturday, I was pretty specific about leaving the paint alone where possible. My guess is that when the car was moved to the factory, this request wasn't relayed clear enough. I'll be working with the service manager on this issue. I noted some key areas that had the more obvious marring damage with the delivery guy who dropped off my car earlier today and also later did a close walk-around video with my phone and a 600-lumen LED flashlight.

    In addition, the loaner ironically had a "Car needs service" prompt during a couple of mornings when I was about to leave the house. At least on the second time, the center screen was frozen but the clock on the upper right was fine. Hmm, maybe I'm emitting weird radiation that causes glitches in these cars? The screen dialog where it prompts to set up a Wi-Fi connection was displayed both times, and perhaps when the 3G signal is weak or if it detects Wi-Fi (802.11) beacons nearby it triggers this weird condition. Who knows.
     
  10. CHG-ON

    CHG-ON Still in love after all these miles

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    The idea of them washing the car when you told them not to really frustrates me. I had a very expensive polishing done that has given the finish a mirror bright shine. I always wash my own car and never want somebody else to do it. I wonder what it will take to get them to understand that no means no.
     
  11. docrice

    docrice Member

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    The car wasn't washed and for me at least they've been very good at honoring such requests (especially upon formal delivery). I think the marring generally just came from them handling the paint directly as they were working on diagnosing the battery problem.
     
  12. CHG-ON

    CHG-ON Still in love after all these miles

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    I find that unacceptable and think that they should fix that for you. Especially at the cost of the car.

    I wrote them about the appalling finish condition of my car at delivery (via flat bed to the house-nice) and they responded yesterday expressing a lot of concern. They even cc'd "higher ups" about the issue and made it clear that they wanted to know what the issue was and they wanted to fix it (too late-had it polished). So I think they will listen if we make enough noise. As they should.

    I'll update as I learn more.
     
  13. scottm

    scottm Active Member

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    Forget the cash washing in this thread, it's about the battery!

    Question: what is the chemistry / technology of the 12V battery. Is it lead acid or gel cel or ?
    Anybody know it's Amp hour capacity? (or "cold cranking amps" ha! that cracks me up)

    Up here in the frozen north, we worry about such things.

    I already saw the "do not park in -35C for more than 24 hours" in the manual.
     

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