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Battery Wear Tracker

Discussion in 'Model S: Battery & Charging' started by SabrToothSqrl, Jul 23, 2015.

  1. SabrToothSqrl

    SabrToothSqrl Active Member

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    #1 SabrToothSqrl, Jul 23, 2015
    Last edited: Jul 23, 2015
    So, I wanted to see how my battery wear compares to everyone else s....

    My Car Data (I'm borrowing a friend's hosting).

    Don't be too harsh, I haven't programmed in several years... after many years I now get to tell people what to make, but rely on them as to how to make it.

    The data is what's important, so I've gotten the basics to collect that, I can make an export to excel function or toss on some pretty graphs, or are there any data points I'm missing?

    Most fields are optional.

    Is this worth me making better, or does no one care?

    I would need a table of all the kWh/mile and max EPA ranges for all versions to do some math with.

    This app is also for US, EPA rated cars, however if you want to do the conversions, feel free.

    Normal Charge means what you normally charge to each day
    # of super charges means... do you use one once a month, or once a day?

    Any fields anyone would like added?

    Eventually you'll be able to search by model year, trim, drive, etc.
     
  2. mknox

    mknox Well-Known Member

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    I entered my data, but this is really duplicating the Plug in America study.
     
  3. SabrToothSqrl

    SabrToothSqrl Active Member

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    I was unaware of their efforts, I see you also have a 85, however the wear seems to be more than mine. Right now a 90% charge shows 227.5 miles

    I'd like a calculated % loss from 'new' (tesla rating), is the goal, to predict how they degrade over time.

    Maybe it's good enough for my own tracking, I do like how they couple entries of the same car.

    Ehh, if it's not worth fixing up, I'll just delete it...
     
  4. mknox

    mknox Well-Known Member

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    Yeah, I seem to be at the low end of the statistics with 216 Rated Miles at 90%. Not sure why. I've tried all the "tricks" to see if I can bump this up, for example doing a couple of deep discharge/recharge cycles to re-calibrate the algorithm and doing a 100% charge to "balance" the pack. I very rarely charge to 100% and most of last summer was charging to 70% and ending my day at about 30%. I figured playing in the middle of the battery's capacity was best, but it was after doing this for a while that I noticed my 90% had dropped a lot when I needed it for a trip. I resumed charging daily to 90% and saw 2 or 3 miles "come back" over time, but that was it.
     
  5. SabrToothSqrl

    SabrToothSqrl Active Member

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    #5 SabrToothSqrl, Jul 23, 2015
    Last edited: Jul 23, 2015
    I keep hearing mention of this algorithm... I don't honestly think the math changes over time.
    EPA rates it a 265 miles/charge new... the pack just doesn't charge as much over time...
    I don't think anything other than it not charging to the voltage (?) that it once did new... is changing...
    Unless wear and tear on the motor/drive over time lessens efficiency (not that likely in 20,000 miles)

    I'm aware the projected range changes based on how you drive, but the EPA range does not.

    I usually rock the 90% charge, but have dropped it to 80 (ish) to charge to 202 miles each day... I only drive, on average 30-60...

    I'm guessing deep discharges are worse than charging to 90 every day, thus keeping it from getting that discharged... but that's only a guess.

    If we had the admin tools Tesla does, we could monitor 1,000 new cars each week, log all charging/use habits, and without question say what's best...
     
  6. SabrToothSqrl

    SabrToothSqrl Active Member

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    #6 SabrToothSqrl, Jul 23, 2015
    Last edited: Jul 23, 2015
    I added a bunch of battery options calculations now, and added the degradation from new % column.

    it will take the 100% charge / what it was new, or if that's not entered, it will use the 90% one vs 90% of new.

    Now we need more data!

    And degradation / miles = loss % per mile or per 1,000 mile more likely.

    If my math is right, at a 8.679% battery loss from new, at 52,000 miles means

    .16691% loss per 1,000 miles driven

    or loss of 0.4423 miles per 1,000 miles driven...

    is that plausible?

    so you've lost .4423 * 52 should be... 22.9996 miles since new... and you're at 242 vs 265, a loss of... 23

    so yea, that math checks out.

    Now Mine

    My Math shows I've lost .58059 miles of range per 1,000 miles. so, close, but actually more in less time, but I'm thinking this levels out after a while.

    New math has been pushed to the site... if you see wrong data - LET ME KNOW, it may be a bug or something I missed.

    thanks.
     
  7. PatD

    PatD Member

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    Slightly off topic, but when my car was BRAND new (For a few weeks), my 90% charge got me to 230 miles. I've never seen it since. Some days I'll show 227 as a high, some days 222 as a low. Not sure why it fluctuates as much as it does.
     
  8. SabrToothSqrl

    SabrToothSqrl Active Member

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    I got mine with 13,000 on it, and 90% charge was also 230 I believe, even with 13k on it... now it's 227.

    It's looking like the most wear occurs in the first 10-20,000 then it levels out.
     
  9. mknox

    mknox Well-Known Member

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    When mine was new, I saw exactly 265 miles with an early 100% charge. Back then, we didn't have the charge slider and there were just two settings, something like "Daily" and "Trip" if I recall. I would get 245 miles on "Daily". Some have postulated that "Daily" actually translated to something like 93% I believe.
     
  10. PatD

    PatD Member

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    I should add - I only have about 3000 miles on mine so far. . . Think a 100% charge for me was more like 250 miles.
     
  11. cgiGuy

    cgiGuy Member

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    Looks like low mileage entries are showing an extremely high "predicted" 10K mile loss. Might need to tweak that to not offer a loss until someone reaches 10K?
     
  12. SabrToothSqrl

    SabrToothSqrl Active Member

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    #12 SabrToothSqrl, Jul 23, 2015
    Last edited: Jul 23, 2015
    If CarMiles < 10000 Then = N/A

    Done.

    I'll max charge tonight to see what my 100% I'm curious if the % holds from 90 to 100.
     
  13. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Mine shows negative loss, although when that pack was installed it showed 268 miles... still shows it today when I do a range charge.

    Something else you might want to capture is the version # of software, because the algorithm changes... would allow you to do some investigation.

    (And yes, after 35,000 miles on this refurbished battery pack, I still show 268 miles after a full range charge, and 240 after a 90%.)
     
  14. SabrToothSqrl

    SabrToothSqrl Active Member

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    I didn't realize over EPA rating was so common. I did see some cars new at full charge with 266...

    that's amazing after 35,000 miles to not have any wear!

    I'll think about the math for you over achievers.
     
  15. mknox

    mknox Well-Known Member

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    Yeah, that's crazy. I saw 265 on the nose once when my car was nearly new. I think all of @FlasherZ's degradation ended up on my battery. :eek:
     
  16. SabrToothSqrl

    SabrToothSqrl Active Member

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    Maybe it was a secret 90 test battery they slipped in there.
     
  17. DoubleDownOn9

    DoubleDownOn9 Member

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    This is pretty cool thank you for making it. Recently my RAV4 EV has been showing me 126 miles on 80% charge which is pretty dang incredible for 2012 with over 30k miles. My 2012 P85 is also showing very minimal degradation (0.63%). I have to say I'm impressed with the Tesla battery. My 2011 LEAF was down to 87% at 35k miles (and that was considered better than average).
     
  18. FlasherZ

    FlasherZ Sig Model S + Sig Model X + Model 3 Resv

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    Or mine soaked it up in the first battery. My rev A pack was down to 227ish at 90% (248 at 100%) at 19,000 miles.
     
  19. SabrToothSqrl

    SabrToothSqrl Active Member

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    Thanks. I don't know what the RAV4 was new, so I don't have much to compare it to. I've read that batteries that do not have their own HVAC system degrade much faster, and saw a recall/offer on the leaf recently.

    Looks like I have bad data in one of the number fields - It doesn't do any error checking yet, so I have to manually clean out the DB.
     
  20. Andyw2100

    Andyw2100 Well-Known Member

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    #20 Andyw2100, Jul 28, 2015
    Last edited: Jul 28, 2015
    Thanks for putting this together.

    I entered my data. Actually I entered it twice, as I'm posting from my phone, so perhaps you can delete one of my entries. (I didn't see a way to do it myself.)

    A couple of points...

    The first option for number of times we have supercharged seems to be miising the zero. It looks like you intended it to be 10 or less, but it reads 1 or less.

    Also I think for some of our numbers to be meaningful you need to add the P85D and P90D models. My P85D's rated range is very different from an S85D's rated range, but right now there is no way to tell our cars apart.

    Thanks again!
     

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