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2020, 2019, 2018 Model 3 Battery Capacities & Charging Constants

Discussion in 'Model 3: Battery & Charging' started by AlanSubie4Life, Jan 21, 2020.

  1. WillyThePooh

    WillyThePooh Member

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    #161 WillyThePooh, Dec 9, 2020
    Last edited: Dec 9, 2020
    Thanks for the response! That was fast :)

    That sounds about right in terms of the constant. I usually charge up to 90-95% SOC, so I'll keep an eye on how much this varies and I'll post the updated pics if I see a significant change.

    One other thing I was wondering is, how does ambient temperature affect these data and calculations? From what I could find, it looks like most of the EPA's testing is done at 75 F (~23.9 C). Since my data were taken in 3 to 4 C (37 to 39 F) ambient temperature, would this affect any of our derived values?

    I'm assuming Tesla's algorithms take temperature into account when calculating projected range (at least indirectly through the higher average energy consumption).

    If the ~20 km rated range increase is mainly due to the addition of the heat pump system, I really want to grasp how temperature is accounted for.
     
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  2. AlanSubie4Life

    AlanSubie4Life Efficiency Obsessed Member

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    #162 AlanSubie4Life, Dec 9, 2020
    Last edited: Dec 9, 2020
    Indirectly through higher consumption. The constant does not change (except possibly one single time in an upcoming software update to get you to your apparently promised 263 rated miles).


    Note that for trips you should just use the trip planner on the other tab of the Energy screen (Trip). It is much better as it takes into account elevation, recent consumption, etc. The Energy Consumption page is useless, except for figuring out your battery capacity, TBH. I never look at it as it is basically irrelevant.

    I’ve explained elsewhere, you can look. There are five test cycles. Two of these use climate control - one hot, one cold. The heat pump does substantially better in these. This allows Tesla to claim a higher multiplier than 0.7 on their weighted two-cycle test results (which are done at room temperature). They claim (it is a defined formula) about 0.746 or so. This therefore results in higher EPA range. That is how the EPA range becomes a function of the heat pump; it’s folded into the scalar.

    EPA range = (0.55*UDDS+0.45*HWY)*scalar

    That results in more rated range than prior years. Basically they can specify a lower constant (even if you don’t realize it for a particular drive), so for a given energy, you can display more rated miles.
     
    • Informative x 2
  3. AlanSubie4Life

    AlanSubie4Life Efficiency Obsessed Member

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    #163 AlanSubie4Life, Dec 21, 2020
    Last edited: Dec 21, 2020
    Alan wins the bet (of course)! (We did not actually finalize the bet though.)

    US 2021 Model 3 that will show ~353 rated miles at 100%

    The constant is now 137Wh/rkm, as I predicted. With the software update, within a month, as predicted.

    The unlocked battery capacity (on the AWD non-P) is unchanged from 2020, in SMT, as I predicted. (Covered elsewhere with SMT captures in that thread.)

    But, to be clear, I didn't "predict" anything. I just read the EPA documents, and took Tesla's number from their website, which says the EPA estimated range of 2021 Model 3 AWD is... 353 rated miles.

    For some reason @TimothyHW3 doesn't want to believe the EPA documents, which have always been quite reliable.

    Now...there is still the unresolved question of whether it's possible there are some AWD non-P vehicles out there with the larger (but locked) battery capacities, which the Performance all have (the Performance may have the same battery as AWD, unlocked, or a denser battery mostly unlocked (I suspect the latter) ). But that's a separate question.
     
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  4. Phlier

    Phlier Bluebird

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    The important parts are in bold.

    Do yourself a favor on your next road trip, and take Mr. Subie's advice.
     
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  5. Masa

    Masa New Member

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    F70BD146-1FEF-4D91-9037-C67459D3026F.jpeg 2020 M3 LR AWD. Took Delivery in September 2020. I am getting far less range than I expected. I charged to 95% (300 miles) and drove around the city and freeway. Drove it down to under 18% in 2 days. Only drove about 120 miles. Do I have a Bad battery. Can anyone tell me if this is normal?
     
  6. LargeHamCollider

    LargeHamCollider Battery cells != scalable

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    Did you leave it in the cold overnight not plugged in? Cause that will drain it quick even though it's not being driven.
     
  7. AlanSubie4Life

    AlanSubie4Life Efficiency Obsessed Member

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    #167 AlanSubie4Life, Jan 3, 2021
    Last edited: Jan 3, 2021
    Seems fine. With your vehicle constant of around 242Wh/rmi (discharge/displayed about 231Wh/rmi) that driving would have used ~187-189 rated miles. (120.1mi*358Wh/mi/(0.955*0.99*242Wh/rmi) = 188 rmi.) You have 61rmi left and that leaves only 300rmi -61rmi - 187rmi = 52 rated miles unaccounted for, max. (52 rated miles is 242Wh/rmi*(0.955rmi/1rmi(displayed)) * 52rmi(displayed) ~ 12kWh)

    If you use Sentry Mode or whatever other features (your screen suggests you are trying!), that could easily account for a lot of the remaining energy (Sentry uses about 1 rated mile per hour, very roughly). Some of course can also be used to heat the car remotely or when sitting in the car in Park (all such use when in Park is not counted on the meter).

    Cold isn’t an issue for your car since you are in LA.

    Anyway, seems fine. If you want to know your battery capacity just take this picture and do the calculation.

    I expect you’ll have 76kWh as a result from that calculation, which is fine (you started around 77.8kWh).

    No problems! Perfectly normal. If you don’t want it to use any significant energy on this timescale, make sure it is sleeping and you are not using any third-party apps or features like Sentry Mode.
     
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  8. Masa

    Masa New Member

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    Thank you for the info! I will try disabling sentry mode if not necessary.
     

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