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SMT: Nominal Full Pack tracking
- Thread starter benyl
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- battery scan my tesla
I believe this version is from the same developer as SMT using Android. Is that correct? But the format seems totally different and the charts seem messy and difficult to read with everything mixed in there.
Do you know if the data can be listed in a table format like the original SMT readouts?
nayr14
Member
The developer plans to do that. This is the new version that was written using a cross-platform framework so eventually it will be available for iOS and Android. He mentioned that the existing readout format will be added back as well.
AlanSubie4Life
Efficiency Obsessed Member
Just installed SMT. Thought I'd share the data here of the results:
Car 1 (Tesla model 3 LR DM, dec 2019 delivered):
Nominal full pack 76.3 kWh
ODO: 7994 km (sorry for the metrics here)
Always charge to 60-70%. Only higher when on vacation (winter trips to the Alpes)
Car 2 (Tesla model S 75D, dec 2018 delivered):
Nominal full pack 68.5 kWh
ODO: 37186 km
My girlfriend charges this car to 90% every day (not a care in the world). I would have expected this one to be higher, more in the low 70's. Something to keep monitoring.
Looks like my M3 is in good shape. So I'm at least 50% happy
I want to see what the new readout looks like for this particular Model 3. Just because it should still show 310, unless this is a 2020 model, which it might be.
Wondering how SMT is deciding 77.8kWh is the max (this is the new degradation display limit for 2020 AFAIK, though happy to be corrected, that is my recollection) and what happens to the display of 100% miles on older vehicles when they are above 76kWh (used to be the old degradation display threshold) with the new UI. Those vehicles are pretty much unicorns at this point though I would think.
To be clear, both older vehicles and newer vehicles had about 77.8kWh when new, so I’d expect SMT to show that for both 2020 and prior model years. The only thing that is different, I think, is how low they go before showing a change in rated miles at 100%.
Would be great to see evidence of this (SMT scans when new and after some aging after it passes through the degradation limit), though. It’s like the Holy Grail. I have been ignoring “battery-gate” during the pandemic, so maybe someone here has posted the key details in the last couple months proving/disproving the theory.
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MarcG
Active Member
I had the same question for the developer of SMT, and he said this (source: #583)
77.8 is read from the car, recently discovered signal and only for Model 3. It seems like a hard coded value (for that battery size), so we'll see how useful this is, if it just creates panic among owners I might remove it later. But it makes the scale look sooo useful, right?
And (source: Vendor - Scan My Tesla, a CANBUS reader for Android):
Model 3 has a signal that we recently discovered, that reports the 'new' full pack capacity. Not sure how accurate it is yet, it seems to be a hard-coded number equal for all cars (of the same battery type), as we know the battery and BMS 'settles in' a bit the first few weeks of ownership, and then start reflecting the actual capacity. I am worried that the degradation numbers will show too much degradation with this method, I hope people don't freak out and go bananas. As they usually do when they realize their current battery capacity. If it causes too much drama, I will remove it.
I should also give something to the S and X guys, those cars don't report this number (that we have found). I thought something as silly as they having to enter that number manually. That way, I don't have the impossible task of combing the whole internet to try to find all the different Nominal numbers from the different batteries, trying to auto-detect which battery each person has, and end up in a crossfire of lawsuits when people go bananas and sue Tesla for the (potentially wrong) numbers I put there
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AlanSubie4Life
Efficiency Obsessed Member
Thanks. That makes sense. It’s roughly the value we would expect, of course, based on prior discussions and posts. I asked him whether it is the same for 2018/2019 as it is for 2020.
MarcG
Active Member
My M3P is an March-2019 build and reports 77.8kWh as well, so it sounds like it hasn't changed. I think the question might best be posed to a sample of 2018, 2019 and 2020 owners who have the long-range battery and run SMT with the latest version, since the value isn't hard-coded by the developer, but reported by the car via CAN bus.
AlanSubie4Life
Efficiency Obsessed Member
Thanks. Yeah. Not really surprised at this either way. Batteries always seemed to start near 78kWh based on what I have seen, even for older vehicles.
Any suggestions what someone like myself with a 9/18 P3 build with 100% only registering 282 rated miles should do?
Local Tesla service center assures me 282 is lower than 310 because of my driving habits, which I know is bogus.
AlanSubie4Life
Efficiency Obsessed Member
This is normal. I know someone with a 8/18 build with 280 miles.
There is nothing you can do about it. Quite a few anecdotal reports of batteries in that timeframe (August/Sept) being worse.
I have an October build and it is at 300. Also normal.
It likely makes no difference except on road trips, of course.
You are of course right that it has nothing to do with driving habits. It a measure of energy - has nothing to do with how you have been driving.
I guess I’d feel better if it were everyone. None of my local Tesla friends seem to have anywhere near the loss in capacity I have. I just feel like I never had the full pack capacity from day 1, and my pack was defective.
For 95% of my vehicle use it doesn’t make a difference, but that 10% capacity hit on road trips keeps adding up stop after stop.
AlanSubie4Life
Efficiency Obsessed Member
I think it will be based on 70% of the energy available in the EPA test document (which is about 79kWh, but perhaps they say 78kWh is the minimum starting point).
So that would be 0.7*78kWh = 54.6kWh. Or 223 rated miles for a 2019 (227 rated miles for a 2020). These ratios don’t behave as expected because 2019 don’t show degradation as visible (meaning visible reduction in rated miles) for a while as compared to 2020. (Has to get below 76kWh for 2019 vs 77.6kWh for 2020.)
But I guess we’ll see. Just seems to me they will base it on NomFullPack readbacks. 70% of what you started with seems fair (that would be the numbers above).
Miles are misleading because of the hidden degradation at first, different weight of miles between model year, etc.
AlanSubie4Life
Efficiency Obsessed Member
So when charged to 90% or so, it predicts about 318-319 miles at 100%, right? (Assuming 18" wheel selection) If 20", presumably about 295 at 100%?
Yes, 319 now. It was briefly 322 when car was brand new.
AlanSubie4Life
Efficiency Obsessed Member
Still searching for that elusive data from someone who installs SMT right away when they get their car, with a brand new battery, showing:
1) 322 miles, to see what it says about the energy at that point (essentially, by how much it exceeds 77.8kWh).
2) And then observe the behavior for the next couple months, showing that you lose capacity, but it continues to show 322 miles, until it drops below about 77.7kWh (100Wh below 77.8kWh)
3) And confirm that that 322 miles still clicks off right away when you start driving, indicating the miles are larger, not that there is energy above 322 miles.
Would be good to confirm that behavior at some point. Though I think at this point it's pretty likely that's how it will work.
AlanSubie4Life
Efficiency Obsessed Member
I doubt they capped anything. I vaguely remember that maybe around that 2019(?).16.1 update the behavior changed, but I think they may just have been updating things to more accurately reflect the energy available. At that time people looked at the max voltage I believe, with SMT, and there was no evidence of capping.
In any case, what's important to realize is that you were likely losing capacity since the car was brand new, it was just hidden from you (rated miles were inflated). You probably started around 78-79kWh, and that gradually degraded, until your energy dropped below 76kWh, when it starts to show. You're now at around 298 miles, which is 73kWh.
Unfortunately with Stats he still doesn't allow you to plot battery health by date instead of miles. So it makes it a little difficult to see how sudden the drop actually was.
I more or less saw exactly what you saw, though it degraded a bit faster at first (but you've made up for lost time) - after about 6-8 months of ownership, at 6000 miles (2019.16?), a step down from 310 to 304 for a while, then a step down to 302, followed by a step down to 300, briefly followed by a step down to 298, but that's recovered to around 300 again, perhaps because things have warmed up a bit. In general, I see nearly zero seasonal variation, though, since it's pretty normal temperatures here year round.
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