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S 100D - Sudden 1% range loss

Discussion in 'Model S: Battery & Charging' started by bob_p, Aug 16, 2017.

  1. bob_p

    bob_p Active Member

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    After our S 100D was delivered, we were getting about 307 miles of range at 90%.

    After a software update, that dropped to 301 - which has held steady for several months.

    We took a 600 mile road trip, charging at superchargers, HPWC (48A) and for an hour on a J1772 (40A).

    Now the 90% range has dropped to 297 miles - losing about 1% after the trip - and this time, there wasn't a software update installed to explain the difference.

    Has anyone else seen this?
     
  2. TexasEV

    TexasEV Well-Known Member

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    The algorithm that estimates range (by estimating battery charge-- it can't be measured directly) isn't that precise. A difference of 1% higher or lower in the displayed value isn't meaningful.
     
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  3. chillaban

    chillaban Active Member

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    1% differences are usually just the result of battery calibration and the accuracy of the percentage. You’ll find fluctuations both above and below where you are currently at. Note that doing a discharge to a low SOC and then doing a 100% charge often improves range estimation accuracy but I don’t think it’s worth obsessing over that.
     
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  4. Tiger

    Tiger Member

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    Also you can select whether to use nominal range or range based on your past driving.

    If you spend more energy while driving, the estimated range based on your past driving will reduce.
     
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  5. TexasEV

    TexasEV Well-Known Member

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    No such thing. The toggle for displayed range is between "rated" (based on the EPA rating) and "ideal".
     
  6. kort677

    kort677 Active Member

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    it's interesting that you claim that it is just a recalibration. Upon delivery of my s90d in december of '15 the car would report a 100% level of 287 miles. in a few weeks time that 100% became 279 miles. I have about 24k miles on this car and close to 3/4 of those miles are from my long distance road adventures. the car has has many sub 2% charges to 100% and to this day I still only see a 100% range of 279. the reason I bring this to your attention is that I don't think your theory of recalibration is valid. I can't say exactly why this happens but it could be that some software updates have changed how the car reports it's range. In the whole scheme of things a 3% reduction of range isn't something to panic over, especially since the range hasn't changed any since it began reporting the lower range.
     
  7. ecarfan

    ecarfan Well-Known Member

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    I believe this is the correct way of looking at it.

    @bob_p don't worry about small variations in displayed range at a given charge setting. Just know that in the first year or so of ownership it is normal for the battery to lose about 1% or maybe 2% of capacity. After that yearly capacity loss is typically 1% or less but that trend does not continue forever, in fact it flattens out after a few years. When I sold my 2013 Model S85 recently with 62K miles on it the battery had lost about 3% of its capacity. That is typical.

    All EV batteries lose capacity over time. Tesla has the best battery management system on the market, in my opinion, and capacity loss is minimal.
     
  8. bob_p

    bob_p Active Member

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    Our 2012 S P85 has lost about 5% of range - so I'm expecting we'll see some range loss.

    What's surprising is that it was consistently charging to 301 before the road trip - and when we got the first 90% charge on the trip last weekend, it only charged to 297 - and has stayed there each day this week. We only have 6500 miles on the S 100D, which seems a little early to start seeing a noticeable drop in range.

    We did get the charge down to 40 miles last weekend, which is about 10%, and it's possible the algorithm adjusted the range based on recharging about 80% of the battery (back to 90%).

    We're planning a longer 1500 mile round trip this weekend (total solar eclipse!), and hopefully we won't see another abrupt drop in charge.

    It's true that the charge level is only an estimate of the actual charge held across the thousands of batteries in the battery pack. But whatever algorithm they're using, it was consistently reading 301 before and is 297 now.

    It would be interesting to have the range adjusted based on the actual driving results. I believe one of my past cars did this. We're averaging 307 Wh/mi - and if we had an option for using the recent actual energy usage vs. rated vs. ideal, I'd be tempted to pick the range predicting range based on our driving pattern.

    Anyone else seeing this on their new 100 after 5000-7500 miles???
     
  9. scottm

    scottm Active Member

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    Range estimates are just that. Even % charge remaining is an estimate.

    Cure: leave the battery indicator on percent remaining, not miles range.

    When you do navigations the car will work and report in % remaining at stops, and will tell you if you need to be cautious about driving the next segment because of battery level.

    And you will remove so many worries about degradation ... and just begin living again!
     
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  10. animorph

    animorph Member

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    X 100D delivered March 22, 2017. I saw the "range loss" with the firmware update, but nothing else. We took a 5000 mile road trip in April, before the firmware calculation change. No change in rated range due to the trip.

    If you haven't charged to 100% for a few months consider trying that before a drive in order to rebalance the battery cells. That can add a few miles to the rated range.
     
  11. mkjayakumar

    mkjayakumar Active Member

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    Atleast one time charge to 100%. you should get back the miles you lost.
     
  12. bob_p

    bob_p Active Member

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    Will charge to 100% tomorrow morning at the start of the trip - and see what happens.

    If we end up losing additional range when we get back, may be time to check with Tesla service.

    I realize the range is an estimate, though it's pretty consistently at the same readings - and I also expect we'll see some range loss over time - but this is too soon to start seeing noticeable range loss.
     

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