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Battery degradation - 2019.32.2.2

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Here’s a recap from one of my posts in another thread. AWD with 9K, was charging a couple times a week to SOC 80% (rarely varied unless for road trip). Noticed a decline over summer from 310 down to 298. Switched to charging to 60% and after a couple times was back to 308 and as of last night it displays 310 rated range (using Stats).

Hey @Sherlo, can you tell us what your estimated miles at 100% are currently and also what version of the software you're running? I didn't think to ask that. I'm on 2019.36.2.1 and don't seem to be having any luck.
 
Hey @Sherlo, can you tell us what your estimated miles at 100% are currently and also what version of the software you're running? I didn't think to ask that. I'm on 2019.36.2.1 and don't seem to be having any luck.

Happy Thanksgiving—

36.2.1 and rated miles at 100% has been ranging between 304-308. I played around with stepping up charge level in 5% increments (50-55-60-65) and think the variance comes from when the charge is shutoff (software issue).
 
Happy Thanksgiving—

36.2.1 and rated miles at 100% has been ranging between 304-308. I played around with stepping up charge level in 5% increments (50-55-60-65) and think the variance comes from when the charge is shutoff (software issue).

Happy Thanksgiving!

Yeah, that's what I think too.. It depends when the charging stops - not how much it was charged. Which is why I started charging and stopping to see if I could figure things out. I dunno, I'm at a loss at this point and feel defeated. lol I'm not sure what to do except move on I guess. Now that this has made zero sense, I thought I had something but nope.. I've got nothing. I wonder if there is some kind of history or something that the car keeps track of or something which is why they tell people it will take a couple months to notice a difference when you try to change your charge practices.
 
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So far no change for me. I switched to 70% for the past week. I just hit 90% this morning and there’s no change in miles. :-/

Ah damn, sorry to hear that. It's a real bummer. Not sure why, but this whole thing really bothers the hell out of me. I feel like I can't just leave it alone and roll with it. Really bugs me. I guess I don't have any choice though.. I don't want to keep screwing around with it and end up doing something I regret.

I wonder if keeping the SOC charge to point mixed up would help (or not). We use a lot of miles so maybe cycling between 70, 80, 90, each day or something will give the battery the range it needs and will help over time. Who the hell knows at this point.
 
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Hm.. Sorry, I can't stop thinking about this.

If the rounding error minimizes at the higher the SOC, I'm wondering if that is what helps increase the range.

Here is a side question.. When I've charged to 100%.. It gets there to 100% and then sits for a long while, current still flowing for some time, current slows down, but it's still high. But the miles aren't increasing and the SOC isn't increasing because you're already at 100%.

Where is all that current/energy going in those last minutes?
 
Where is all that current/energy going in those last minutes?
It's hard to say without CANBUS and other analytic data sets. But: Driving the MFD; keeping the HV circuits energized; and cooling the battery all leap to mind. Mostly the latter.

For what it's worth, the changes I'm seeing in my projected range look like simple noise, though I only have a couple kilomiles' worth of data so far.
AnCRWN.jpg
 
It's hard to say without CANBUS and other analytic data sets. But: Driving the MFD; keeping the HV circuits energized; and cooling the battery all leap to mind. Mostly the latter.

For what it's worth, the changes I'm seeing in my projected range look like simple noise, though I only have a couple kilomiles' worth of data so far.

Hey that's cool! How are you seeing this data? Is this something that is only available outside the US? What other kind of data can you see? Can you share more about what you're using to get this chart?
 
Very very very very curious... I always thought the estimated 100% range was a constant multiplied by actual pack capacity in kwh (does not adjust for temperature / driving conditions, etc...). I believe this to be the case for older SW versions. However, like others, I've been seeing rapid degradation lately.

BatDeg1.png

So I exported the data from TeslaFi and changed the X-axis from odometer reading to Date, and plotted estimated 100% range vs OAT (deg F):

BatDeg3.png


If someone told me that in a software update they started taking OAT and/or battery temperature into consideration when calculating range, then I think this would be very believable. Seems like Tesla could eliminate alot of angst by just announcing their intentions.
 
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Very very very very curious... I always thought the estimated 100% range was a constant multiplied by actual pack capacity in kwh (does not adjust for temperature / driving conditions, etc...). I believe this to be the case for older SW versions. However, like others, I've been seeing rapid degradation lately.

View attachment 482594

So I exported the data from TeslaFi and changed the X-axis from odometer reading to Date, and plotted estimated 100% range vs OAT (deg F):

View attachment 482595

If someone told me that in a software update they started taking OAT and/or battery temperature into consideration when calculating range, then I think this would be very believable. Seems like Tesla could eliminate alot of angst by just announcing their intentions.
Interesting! If you've read the whole thread, I showed that @Allistah's data appears to correlate with temp change, as well as mine and @hcdavis3 's data.
 
Interesting! If you've read the whole thread, I showed that @Allistah's data appears to correlate with temp change, as well as mine and @hcdavis3 's data.

Yep, I have. That's what prompted me to look at my numbers. Of course, the proof to would come around March. Once the temperatures start trending up, we should expect to see improved range estimates. Should that be the case, I'll feel a lot better that there is nothing physically wrong with the pack
 
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Hey that's cool! How are you seeing this data? Is this something that is only available outside the US? What other kind of data can you see? Can you share more about what you're using to get this chart?
It's available for anyone to set up and host for themselves; it's an open-source program called Teslamate, and the devs are adding new charts and dashboards rather regularly.

It can be found here: adriankumpf/teslamate

As for what kind of data are currently available to see:
  • An overview, showing current SoC and information about the current charging session (if any), current firmware, interior and exterior temperatures
  • Details about current and past charging session; including location, charging rate, charging efficiency, and a host of other data
  • The upthread-shown degradation monitor
  • Details about past drives, including a path-of-travel map, elevation, temperatures, speed, power draw, state of charge, and range over time
  • An efficiency overview breaking down data by temperature gradient
  • Locations parked
  • Mileage over time
  • The car's current location in real time
  • The car's system state (e. g. driving, asleep, online, charging) over time
  • Firmware update history
  • Vampire drain logging
  • and a few other things I'm forgetting
 
I'll plot mine this way tomorrow as well.... but I live in SoCal, and mine started dropping when outside temps were in the 90's
upload_2019-11-29_7-41-13.png

I guess, if I'm trying to prove there is a correlation, I would try to use this to do so but I Live in SoCal, so "winter" is not exactly a thing (as you can see my outside temps have just now dropped to mid-to-low-60's. And I have what amounts a pretty significant displayed range loss (over 20mi of lower than 264 when new).

EDIT: Will add: This is Dec 2018 build Mid-Range (EPA Rating of 264 mi). purchased Jan 2019. 9.5k miles on the odometer.

@dennis_d - your post is the first I heard of this. Did you see anything from Tesla or your own data?
 
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