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Reduced Capacity & Range?

Discussion in 'Model S: Battery & Charging' started by digitaltim, Sep 26, 2013.

  1. digitaltim

    digitaltim Sig737 VIN628

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    I am coming up on a year of ownership in November and about to cross 30k miles - ~20k on the current battery (1st one was replaced @ ~11k).

    I generally start a max/range charge just before I leave on my weekly commute from MD to NJ to top off - it never sits at 100% for any length of time. I also supercharge twice per week at DE - once heading north and once heading south each week.

    I recently noticed that a full charge only gets about 256 miles - 96.6% - a 3.4% drop from 265.

    I am going to start to track it more closely and plan to discuss with the service center when I stop in for the 32.5k checkup.

    Any other high mileage drivers having a similar experience?
     
  2. dennis

    dennis P85D

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    I am not a high mileage driver but did check a full charge today - 259 miles. I have driven 6200 miles in 11 months and range charged only 6-7 times.
     
  3. digitaltim

    digitaltim Sig737 VIN628

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    261 - 98.5% this morning.
     
  4. pilotSteve

    pilotSteve Member

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    Is it possible with the recent firmware changes (I'm not referring to the slider) that computation of Rated Range has changed slightly? Its also true that if everything stayed the same with the calculation (impossible to know) that this does reflect normal/expected battery capacity loss.

    Thanks for posting this and lets see what other higher mileage owners report.
     
  5. jerry33

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

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    Assuming the pack is balanced. If the pack isn't balanced, then it's not very meaningful.
     
  6. digitaltim

    digitaltim Sig737 VIN628

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    I am still running v4.5 fwiw...
     
  7. vgrinshpun

    vgrinshpun Active Member

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    My car is just over two months old, has 5641 miles. Initially the max charge was 272 miles; it is 267 miles currently.
     
  8. efusco

    efusco Moderator - Model S & X forums

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    Again, I think it's hard to know if we're comparing apples to apples with the various firmware updates that we've seen. I, too, started with a max range charge showing 272 rated. As of this morning I show a max range charge of 260 miles that dropped to 257 miles within a mile and a half of home. Yet when I got home from a 130 mile trip I showed 135 miles of rated range (130+135=265) and my W/mi = 285 for the trip. So what does that all mean?

    I do suspect that v4.5 calculates rate range slightly differently than my original firmware did, but I'm just as sure that over the 17,000 miles I've driven over the past ~10 months that there has been some battery degradation. But I'm not comfortable calculating the amount of degradation by comparing the current Max range charge to my original max range charge because of the firmware differences.
     
  9. gregincal

    gregincal Active Member

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    The other thing I'll point out is that range loss isn't linear, the first year should see the greatest loss. I think 3.4% after 20,000 miles is fine. Even linearly that would be only about 17% after 100K miles, but I bet you'll get a lot better than that.
     
  10. digitaltim

    digitaltim Sig737 VIN628

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    Agreed...

    To be honest, I generally do not pay attention to it, but the 260/261 lately at max range charge caught my eye.
     
  11. NeverEnough

    NeverEnough Member

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    My max is now only 251!!! The car has 9.5k miles and is 6 months old. I'm concerned.
     
  12. AmpedRealtor

    AmpedRealtor Active Member

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    Tesla Ownership recommends keeping the car in a 50%-62% charge state for maximum long term battery life and minimum degradation. This was told to me by several different people in Ownership, and if you ask them they will also confirm this information. Tesla claims the advantage to doing this is "negligible", but what is negligible - 5 miles? 10 miles? 20 miles? Nobody knows.

    The recommendation I was given by Tesla Ownership is as follows. When not operating the vehicle, it should be plugged-in and kept at a 50%-62% state of charge (lower is better). Add appropriate range, as needed, before you head out for the day and as close to leaving as possible so the battery does not sit at a higher state of charge longer than necessary. Upon your return, plug the car in and charge back to 50%-62%. Also, do not let the battery fall below a 30% state of charge whenever possible. This is exactly what I do.

    You have to ask yourselves why Tesla added more granular control to the slider if the above weren't true. Why give owners the ability to charge as low as 50% if there is no benefit to doing so? In prior versions of the software, there were only two choices - standard and max charge. Standard charge, according to the walk-thru video, charges to 85% capacity. In the latest software releases we now have the ability to charge in fine increments anywhere between 50% and 100%. Why add that if it doesn't really matter?

    A lot of owners have been max charging and driving their cars until they hit ZERO range. Now we are seeing reports of what seemingly looks like battery degradation. Coincidence?
     
  13. stopcrazypp

    stopcrazypp Well-Known Member

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    I think adding the additional percentages allows better planning at superchargers (avoiding the top of the pack in order to reduce charging time) without having to manually time and disconnect your car.
     
  14. cinergi

    cinergi Active Member

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    There's a thread for this already -- not that there's anything conclusive in there.
     
  15. TexasEV

    TexasEV Active Member

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    Why? Because this year EPA started rating EV ranges as the average of the "standard" charge and "range" charge. They calculated the range for the 2013 Leaf this way, for example. With a slider rather than a fixed "standard" charge of less than 100% as the previous firmware had, EPA still rates the Model S mileage using just the max range charge. It's a marketing thing.
     
  16. AmpedRealtor

    AmpedRealtor Active Member

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    I don't understand, you are saying the reason Tesla added more granular charging control is because of how EPA calculates range and because it's "a marketing thing"? That seems like an odd explanation, especially since nowhere in the ownership materials or the window sticker itself says anything about how EPA calculates the range, and as far as marketing is concerned, Tesla does not do any marketing regarding the variable slider control. Where?

    And even if the above were true, it still doesn't make sense. Adding granular control over your charge level has nothing to do with either of the things you mention. How could it?
     
  17. bluetinc

    bluetinc Member

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    #17 bluetinc, Oct 1, 2013
    Last edited: Oct 1, 2013
    There are a few stories out there about this, and it's effect on the quoted range of EVs. Here is a quote from Toyota on their EPA rating of the Rav 4:

    "In our recent discussions with EPA, the certification side decided that they should apply the user-selectable interpretation of the drive mode policy—a policy we felt was meant to govern modes that impacted efficiency. And now they are applying that to how we calculate range.

    Since we have the two different modes, we have to test both the city and highway in both the normal and extended mode. We average those, take the 30% reduction, and then once again harmonically average the city and highway cycles. So, in a standard mode of 92 miles, in an extended miles we might see a label range of 113 miles.

    My point is not that the EPA is incorrect. It's a matter of interpretation. We feel that their interpretation is misguided in this particular application. But it really is confusing to the customer and to the general public when we talk about range calculation. Averaging two different modes and coming up with a number is very difficult to completely understand."

    —Sheldon Brown

    Here is a link to a video where it's also mentioned, right around the 7:50 mark Live from Expand: Toyotas Sheldon Brown - YouTube

    Peter

     

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