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Pack Replacement Thread

Discussion in 'Model S: Battery & Charging' started by walla2, Feb 20, 2014.

  1. walla2

    walla2 Member

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    #1 walla2, Feb 20, 2014
    Last edited: Feb 20, 2014
    So, as many of you may or may not know, more than a few cars have had their entire high voltage pack replaced under warranty.

    I recently had mine replaced, and it has brought up what could be a serious policy issue at Tesla. Tesla has proposed a workaround for me, but I am skeptical about it. Here goes:

    So in January, my pack fails and leaves me mildly stranded. Tesla Ranger service is awesome. They come and get the car the next day and replaced the pack in 1 day. I'm told my high voltage pack failed but not given much else.

    The car is brought back to me and I immediately notice that my standard rated range is less than I was expecting. I had known my max rated range just before the pack failed to be 257 miles. So I range charged my replacement battery and now can only get 250 miles rated.

    I contacted Tesla and was told:

    1. Engineering since 2 firmwares ago has been altering how the rated range is calculated adjusting for how the driver drives. It's a work in progress and not a published one.

    If this is true, why would the ideal range also be less? Is ideal also affected by driver style and why would that be? I asked why Tesla has said anything about this change and recommended they do so.

    2. Engineering recommends that I charge the car to 100%. Unplug it for 30 minutes and then drive it down to 20% and leave it unplugged for 30 minutes. Then recharge to 100%, unplug, and repeat 3 times total. This is supposed to have the pack relearn how I drive and is supposed to increase rated/ideal range.

    This is quite the protocol and not going to be easy with my 10 minute or less commute, but I will do it. I want the miles back if possible.

    3. Finally, engineering recommended balancing. They told me to charge to 100% and leave it that way for 3 days without driving.

    I hadn't heard this method of balancing.

    I haven't followed some of the threads here, but I am skeptical as to why doing any of this will restore my range to a higher state. I'm still going to do it, but I suspect my refurbished type A pack has more miles on it (a lower SOC) than my original type A pack, and that the current corporate policy is just to replace it with what is available, get the car on the road quickly, and not worry about SOC. It's new territory in terms of policy for sure. I hate to have had to trailblaze again. I know several others that have had a new pack replaced with a better battery (B) with higher range (272 reported here). So some driver's driving styles don't affect rated and ideal range? Others have received refurbished A packs, B packs, and I even saw a D pack here that looked like a refurb sticker. What happened to their SOC's? Better, worse, the same? I can't see how it could be right that my replacement battery for their pack failure can do less than what I turned in and that some technical feat of charging will change magically things. I think I just received a worn pack that will never do what my original pack was able to do.

    Again, I am going to go through the motions and then recontact Tesla and recontact you here, because I think this is an important issue. Anyone else going through something like this?
     
  2. Chipper

    Chipper Active Member

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    I am surprised Tesla is not the one doing the charge/discharge and balancing before installing the replacement. This seems an undue hassle for the recipient.
     
  3. deonb

    deonb Active Member

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    This has indeed been suggested many times on the charging threads on here, and is the most effective way to restore your range display to the higher state.

    You can't just charge to 100% and leave it, you have to keep it plugged in while it is set to 100%. And only ever do this in cold weather.


    If you're very concerned about it, watch through the video in this thread - it completely put my mind at ease:
    http://www.teslamotorsclub.com/showthread.php/27109-Why-do-Li-ion-Batteries-die-And-how-to-improve-the-situation


    I don't believe #1 and #2 above for a second. Based on the weather over here, my winter and summer driving behavior are incredibly different, yet the rated range stays exactly the same. And in my case the range displayed is so far removed from reality in the summer that if this was really a dynamic calculation, it would be a ridiculous embarrassment to the programmer that implemented it. And why would this not be a reading that changes per driver?

    Software upgrades indeed do change the available range, but it's not further affected by driving style. I think when engineering says this, they're at most talking about the energy graph - which indeed is affected by driving style - rather than the range. (Pet peeve of mine that Tesla doesn't have their service staff get any real experience with the car, so they don't know the difference).

    Also if #2 was true, then doing what engineering says won't give you any real additional range. It will simply affect what gets displayed and possibly influence the kWh/mile calculation.
     
  4. zwede

    zwede 2013 P85+

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    Is it possible they updated the SW at the same time they replaced the battery? I hear that with one SW update they added a few more miles to the reserve (below 0 miles left). That would mean they moved the whole scale a bit, decreasing both rated and ideal miles.

    Just throwing it out as a possibility...
     
  5. yobigd20

    yobigd20 Well-Known Member

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    I call BS on this one. AFAIK rated range has NOTHING to do with driving style.

    Given that I'm almost at 40,000 miles, with a total average of 382Wh/mi, and most of my winter driving is near 500Wh/mi, if the pack "learns my driving style and adjusts rated range accordingly", then my 100% rated range shouldn't be showing me 255 miles .. instead if it "knows how I drive" it should be telling me my max rated range on a full charge is like ~150 miles, lol.
     
  6. AmpedRealtor

    AmpedRealtor Active Member

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    I totally agree. The speedo range estimate absolutely does not take driving style into account. I did my first max charge last week and got 301 ideal and 265 rated miles. My car is 6 months old with just over 5,500 miles. I don't care what Tesla says, it's simply not true because my numbers never, ever change no matter how I'm driving.

    -- foil hat on--

    The conspiracy theorist in me might suggest that Tesla Engineering knows it has a pack degradation problem on its hands. In order to stall for time until they figure out a fix, they told their front line people to tell concerned owners that it's a change in the algorithm. That will keep owners quiet while they chase ghosts. In the meantime, Tesla is figuring out what to do with this whole thing.

    -- foil hat off --

    In reality, I think there are certain usage patterns that are impacting the algorithm or that there is some pack imbalance happening that Tesla did not anticipate. Hopefully v6.0 software will see some range return. I am very interested to know how this is all going to work out.
     
  7. Kalud

    Kalud Member

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  8. qwk

    qwk Model S P2681

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    The driving style range difference talk is pure BS, plain and simple. My car has 14k miles on it, and is 1 year old. Range charge is 265 in warm weather, and 262 in 32*F weather(no garage). I have gotten as low as 260 miles in range mode, but multiple range charges have brought that back to 265.

    Like I stated before, the A packs seem to get out of balance easier(like the roadster), and it takes much more effort to get them back into balance. I'm sure some of Tesla's packs have some degredation, but it seems like the majority are just out of balance.
     
  9. Zextraterrestrial

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    fully agree. (but sadly my full charge is less)

    & Walla2's pack was probably replaced with one that was more out of balance.
     
  10. apacheguy

    apacheguy Sig 255, VIN 320

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    This is nothing more than Tesla's excuse for decreasing rated range. The fact that some people still get > 265 miles on a charge is proof that they have done nothing to affect the max range charge calculation. You correctly point out that one user reported having his pack swapped and immediately noticed a bump up to 272 from the 257 he was previously at. Explain that one, Tesla.

    Amazing that you still see those numbers with that high of a mileage and energy consumption.
     
  11. qwk

    qwk Model S P2681

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    It's been explained dozens of times, some people just fail to listen.
     
  12. RichardL

    RichardL Member

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    I added my info to the Battery Wiki - I have a D pack from December
     
  13. DFibRL8R

    DFibRL8R Member

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    If the battery life is best when cold, why does the car want to heat the pack in warm temperatures? I assume it improves output/performance but does this come at the expense of battery life? If it is just for improved performance, seems like there should be an option to choose to heat the pack to improve performance/power. Personally, I don't need the car constantly ready to do the best possible 0-60 sprint but maybe I don't fully understand the point of warming the cold pack.
     
  14. qwk

    qwk Model S P2681

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    I would bet that it heats the pack so that regen comes back fairly quickly. If you put the car into "range" driving mode(nothing to do with range charging), the battery heater will only come on at temps below 10* F, and turn off once acceleration power is only limited to about 120kw. You will not have regen however, unless you drive a very long time(hours).
     
  15. apacheguy

    apacheguy Sig 255, VIN 320

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    Not sure I follow. I have closely read the decreasing rated range thread and the consensus we reached was that it was due to imbalanced packs, NOT Tesla changing the range calculation (which I think is pure BS). Would you mind posting a reference to your statement?
     
  16. qwk

    qwk Model S P2681

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    The service center folks usually don't know much aside from replacing parts. Complex cases are sent to engineering for review and diagnosis. Having said that, why in the world would anyone take anything the SC employees say as fact? Engineering employees have to sign NDA's, so you won't be hearing anything from them unless top management approves it. This is where the problem lies.
     
  17. djp

    djp Roadster 2.0 VIN939

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    The battery needs to be above 50F to take a charge, so you'll have a regen limit if the pack is below that temperature. The operating range of the battery is between 50F and 140F (10C - 60C).
     
  18. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    You have to distinguish between what's best for the battery when it's being stored vs. when it's being used (charge/discharge). Storage life is optimized at a lower temperature than charge/discharge. Here's a good reference.
     
  19. walla2

    walla2 Member

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    Let me be clear, I do not believe 1 and 2. That is just what I was verbatim told. I haven't followed balancing stuff because I haven't needed to until now. My other pack was healthier. My refurbished pack is less healthy, and I plan to see what happens to it.

    - - - Updated - - -

    That looks like a refurbished sticker. It's smaller and narrower than any of the other stickers and this is consistent with other refurbished stickers I've seen here. Any other new cars have these narrow stickers?
     
  20. yobigd20

    yobigd20 Well-Known Member

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    yea my honest opinion on this whole matter is that I think my pack is just more balanced than everyone elses. I use very heavily every day. I've been down to < 30 miles occasionally, and I've ranged charged it to 100% a bunch of times too (but ALWAYS times such that it's never at 100% for more than ~10 minutes).

    I really just think that my SOC is a more accurate estimate since I've gone so low (I have had it to 0 twice), and then topped it off to 100% after those discharge depths. And I ALWAYS have it plugged in...ALWAYS. if i'm not driving it, it's plugged in. It's plugged in at work (so technically my daily charging habit is from 90%->~37%->90%->37%->90%), and when I'm home even for errands on weekends in and out in and out I'm always plugging it back in when I'm home. The *ONLY* time it's not plugged in is 1) when I'm driving and 2) I've gone somewhere that doesn't have a charger (usually errand related so not "unplugged" for long). @work I charge [email protected] and at home I vary it between [email protected] I've only HPWC once (at King of Prussia mall, was limited to 60A at the time) [side note: I have a HPWC at home but it's been sitting in its box for a year, the NEMA 14-50 I installed is plenty]. I've only supercharged twice and I never range charged it on a supercharger either.

    What even more amazing though is that I'm still on the original OEM 19" goodyears with a LOT of tread left. I should be able to make it close to 60k before they are down to 3-4/32".
     

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