AmpedRealtor
Well-Known Member
I don't believe your vehicle is one of the vehicles impacted by the software-induced range loss.I saw no drop in range. The car ran the tests over a couple of days, but it didn't find any bad cells.
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I don't believe your vehicle is one of the vehicles impacted by the software-induced range loss.I saw no drop in range. The car ran the tests over a couple of days, but it didn't find any bad cells.
Your data shows pretty good degradation. The TMSpy data also shows that they use the "Nominal" fullpack (includes the 4kWh buffer). Their SoC is the nominal remaining divided bybthe nominal full pack. This when you were at or near zero percent usable TMSpy shows 5+%.I re-did my test yesterday one one non-stop drive from 100% charge down to zero (excluding the anti-bricking buffer). Actual zero is impossible, but I had to dead-stick it into the Sheetz parking lot and push it into a Supercharger stall. It wouldn’t go into any gear.
This time it showed 71.8 kWh used in the 240.3 mile trip at 299 Wh/mi (slightly more efficient than the 310 rated for a P85D).
If 85 packs originally had 77.5 useable, then I am down 5.7 from new, or 7.3%. Which doesn’t seem all that good for a pack with only 28K miles.
Battery voltages at 100% charged (five minutes after unplugging with charge complete):
View attachment 427345
Battery voltages at empty:
View attachment 427344
Dashboard with trip info:
View attachment 427342
Maximum rate seen during Supercharging:
View attachment 427343
It seemed it took about 5 minutes after plugging the Supercharger cable in before the car started charging. Group 57 appeared to be about 55 Mac less than any other cell groups. I hope I didn’t damage anything, but isn’t that what the bottom-end buffer is for?
That's what I am seeing Full pack is around 60 kWh. I started with a full topped off battery. Finished with 7% remaining having used 58.1 kWh. So lets forget about miles and talk about kWh. It seems like 2019.16.2 reduced kWh. It had been at about 5% degradation previously. Or 73.15 kWh. Now around 60.0 kWh. So about an 18% loss in kWh thanks to 2019.16.2. Sound right?But now my rated range is 217 miles and Usable full pack of 60.3kWh (23%).
My estimate is 8kWh loss with 2019.16 2.That's what I am seeing Full pack is around 60 kWh. I started with a full topped off battery. Finished with 7% remaining having used 58.1 kWh. So lets forget about miles and talk about kWh. It seems like 2019.16.2 reduced kWh. It had been at about 5% degradation previously. Or 73.15 kWh. Now around 60.0 kWh. So about an 18% loss in kWh thanks to 2019.16.2. Sound right?
I don't believe your vehicle is one of the vehicles impacted by the software-induced range loss.
I re-did my test yesterday one one non-stop drive from 100% charge down to zero (excluding the anti-bricking buffer). Actual zero is impossible, but I had to dead-stick it into the Sheetz parking lot and push it into a Supercharger stall. It wouldn’t go into any gear.
This time it showed 71.8 kWh used in the 240.3 mile trip at 299 Wh/mi (slightly more efficient than the 310 rated for a P85D).
If 85 packs originally had 77.5 useable, then I am down 5.7 from new, or 7.3%. Which doesn’t seem all that good for a pack with only 28K miles.
Battery voltages at 100% charged (five minutes after unplugging with charge complete):
View attachment 427345
Battery voltages at empty:
View attachment 427344
Dashboard with trip info:
View attachment 427342
Maximum rate seen during Supercharging:
View attachment 427343
It seemed it took about 5 minutes after plugging the Supercharger cable in before the car started charging. Group 57 appeared to be about 55 Mac less than any other cell groups. I hope I didn’t damage anything, but isn’t that what the bottom-end buffer is for?
Worth an update here.
Tesla has changed the balancing algorithm many many times over the years. Originally this was a very dumb setup that would only kick in once a cell group reached a threshold voltage, usually around 90-93% SoC. This is no longer the case.
First, let me point out that Tesla's BMS software has come a LONG way... I'd consider it a work of art now. Lots of genius in there. It's absolutely amazing and full kudos where kudos are due here.
One thing they're now able to do is to calculate out the capacity of individual bricks of cells (96 in the 85/90/100, 84 in the rest) based on a ton of factors and compute this in near real time, in a full range of conditions, with almost magical accuracy. They're basically running physics simulations (similar to how they calculate out unmeasurable metrics in the inverter firmware, like rotor temperature) of the entire pack based on measured power usage/charge, balancer usage, temperature, temperature delta based on coolant flow and coolant temp, predicting temperature gradients, and probably 100 more variables. This is the holy grail of proper balancing for safety and longevity for a battery pack. This is not a dumb system anymore by any means. Knowing the actual capacity of the individual bricks allows them to know exactly which ones need cell bleeders enabled, and for exactly how long. With this data, they can balance on the fly at any SoC, and just use top and bottom SoC windows for fine tuning, validation, and calibration.
The car balances all the time whenever its needed. It knows when a cell group will need balancing before it's even out of balance... which is really freaking weird when you think about it, especially if you're watching a playback of the pack balancing and voltages and see it engage a balancer on a cell group that doesn't look out of balance at all, and watch it fall completely in line still at the end of a charge or discharge cycle. It keeps track of which groups will need it, which wont, how long they'll need it, how much they've been balanced, etc.
It really is an epic setup now.
The short answer to the balancing question: It balances any time it needs to balance.
As for SoC shenanigans, yes getting closer to 100% or 0% will give it a chance to tune things better... but it's not needed anymore. Just charge like you need to, and drive.
An update for this topic.If you could actually get 75 kWh out of a 3 pack, I'd expect dozens or more independent examples all over this forum, YouTube, etc... not just one Tesla fanboy.
Thanks wk057 providing so much information for years. I like these discussions. Just sharing what I saw.
An update for this topic.
There are several Scan My Tesla pictures showing 76-79 kWh nominal in recent months. Here is one below.
BTW, does anyone know a good thread/explanation about why energy used in trip meter never came close with nominal kWh, even with driving from 100% to 0% nonstop as Bjorn did?
View attachment 543204
Those are just values reported by the BMS, which unfortunately for the Model 3 packs are solely for our benefit. Those particular values are not used by anything in the car, and only people reading CAN data will see them. They don't tend to match values reported by the BMS debug interface.
Edit: usable kWhdoes anyone know a good thread/explanation about why energy used in trip meter never came close with nominal kWh, even with driving from 100% to 0% nonstop as Bjorn did?
Many people do see close to usable being available, but you have to do a mostly continuous drive, without stopping for any long periods of time.Edit: usable kWh
Usable = Nominal - Buffer
Because the car doesnt calculate using nominal at the end, it switches to usable as the energy approaches zero. Zero miles on the dash = 4kw remaining for nominal remaining capacity.Thanks wk057 providing so much information for years. I like these discussions. Just sharing what I saw.
An update for this topic.
There are several Scan My Tesla pictures showing 76-79 kWh nominal in recent months. Here is one below.
BTW, does anyone know a good thread/explanation about why energy used in trip meter never came close with nominal kWh, even with driving from 100% to 0% nonstop as Bjorn did?
View attachment 543204
Also, given the fact that most Model 3 LR batteries are closer to 78kWh when new, and given rapid degradation early on, the chances that a new Model 3 owner does 100% to 0% drive nonstop to hopefully see the 75 kWh since last charge is very rare.
I find that most new owners of EVs (which is what most Model 3 owners are) to be initially conservative and shy away from driving the car down to 0%.
That being said, given a lucky new M3 owner that gets 79kWh nominal pack when new, if adventurous enough, it could conceivably be possible to use slightly over 75kWh on a 100% to 0% continuous drive.
The buffer is about 4.5% of nominal pack, so on 79kWh nominal that’s 75.445kWh useable. Of course, the dumbed down Tesla UI does not show decimals, so you would only see 75 kWh, which makes @wk057 correct when stating you may never see over 75kWh displayed in the since-last-charge screen.
The 78/79 numbers are imaginary. They're the result of incomplete calibration to the real pack, combined with the fudge data in the 3 BMS. The "rapid degradation" at first isn't degradation at all.
(To be clear, the reasoning behind why the CAN-reported values don't match reality may not be, and likely isn't, nefarious... my guess, based on what I can tell from my RE work, is that they just didn't care if those values were accurate since they weren't used by the vehicle... internally, there are more accurate values that aren't reported on CAN and require active polling to retrieve.)