AlanSubie4Life
Efficiency Obsessed Member
It wasn’t average consumption. Just the rated constant (which is 5Wh/mi below the rated line).
Constant = Degradation threshold / EPA rated miles
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Battery Degradation Year 1
- Thread starter LiquidXTC
- Start date
Constant = Degradation threshold / EPA rated miles
The reason for the 82.1 <> 77.8 initial capacity discrepancy is Tesla recently reclassified some of the energy efficiency labels in the firmware, and now there are two different batteries using the same internal label. You'd either have the 82.1 pack or the 77.8 pack.
Initial capacity is the max range/energy reported by cars in the real world at ~0 mi odometer with your model/trim/efficiency label. Usually it works super well but if you've got a pack with duplicate labeling you might need to set your own. Hopefully they separate out the labels in the future or there becomes some way to identify packs with 100% certainty remotely.
Initial capacity is the max range/energy reported by cars in the real world at ~0 mi odometer with your model/trim/efficiency label. Usually it works super well but if you've got a pack with duplicate labeling you might need to set your own. Hopefully they separate out the labels in the future or there becomes some way to identify packs with 100% certainty remotely.
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In the old days, the best way to determine the degradation was to deplete the battery from 100% to 5% or lower and register the kWh used and compare them to either the posted usable battery capacity or to other readings previously taken. Nowadays everyone is using tools that are more or less perfect. And many people consider degradation based on the range @ 100%, which is misleading. Why ? Tesla take the EPA rating (the official energy consumption figures per mile from regulatory testing) and assume that a mile requires that much energy. The battery management system (BMS) works out how many kwh of energy are available and converts that to miles or km using that official efficiency figure. Problem is, the BMS in time, can have errors in reading the lowest and the highest voltage of the cell pack, especially when people are driving usually no more than 20-30% SOC in a day.
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UncleCreepy
Member
I agree it will never be 100% accurate, no matter how you measure it. If you compare two data points they need to be taken at the same battery temperature, too. I once decided to precondition the car before connecting it to a level 2 charger. While the car was standing and not connected to the charger, the SoC and the remaining miles actually went up at first. I had several instances of phantom gain instead of phantom drain, too.
I'm not worried about battery degradation at all. It does happen, but it's not bad enough to matter. Imagine the car starts at 500 km and you deem the battery unusable at 70% (350 km). So the average would be 425 km per full charge and Lithium batteries will easily survive 1,000 full charge/discharge cycles. That makes 425,000 km. Maybe a little less if you regularly need more than the rated mileage or even more if the battery lasts for 1,500 full cycles.
Either way, I've never had a car for that long, so degradation is not really a concern for me. By the time the battery is no longer usable there will probably be better products anyway, so the replacement cost for the battery becomes a non-issue, too.
As it is a facelift, Id say no M3P facelift was soldxeith the old battery, so all should have 82.1 if nit any wicked battery change was done?
I see more strange values than correct, very often with ”very low” degradation.
If theses cases are worked true (checking original capacity and rated consumption etc, and the range at 100% and/or a energy graph calculation is performed, the picture will be completely different.
This is the most common Tessie appearance in forums abd facebook:
I think he states that he did not change the initial value (I dont know).
Its a model 3 LR RWD with the 77.8 pack.
The model 3 P facelift in europe had the 82.1 pack for 1 1/2 years but the initial value on many is set to 78.8 (the LG pack these cars does not have.)
The degradation value ”looks good” but it is not really a true value.
I do not use Tessie but would have gained 0.1 kWh from new after 2 1/2 years and 62K km with this initial value.
I regularly see way to low initial value, and the owners think ”its the net value, without the buffer”
So when Tessie set my Model Y to 78.5 by default, is that detecting the 82.1 and setting a start point?
TBH, I've been trying to follow but still have no idea how I can get my current rough degradation in Tessie
At around 3200 miles (car purchased in Feb 2023), I'm seeing 0% default and 4.1% when set to 82.1.
Tessie can't see or know the buffer. I regularly see that low value reported as well, but those are outliers - it's rare to post questions about being perfectly average, which is logically where most people are.
What I'd really love is to provide a nice breakdown (like 80 kWh total, 3 kWh buffer, 77 kWh usable). That's the dream. Hopefully Tesla eventually provides a way to see it.
78.5 is what other cars with the same config reported at 0 mi odometer. Hard to tell if you won the battery pack lotto or if there's something different with your battery versus other owners with that config.So when Tessie set my Model Y to 78.5 by default, is that detecting the 82.1 and setting a start point?
TBH, I've been trying to follow but still have no idea how I can get my current rough degradation in Tessie
There's a sticker on the front right side of the battery that can provide some insight. You can see it if you look under the car around the front right wheel. If you Google that model you might be able to find out the capacity when new that's been measured with hardware (e.g. OBD scanner or a car teardown.) Otherwise some people use ScanMyTesla with an OBD scanner to verify the underlying battery pack data.
edit: subtract buffer inclusion
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When using the charged energy as the source for capacity, the buffer will be included.
When charging 1km or mile, the ”added” energy for this is value is slightly higher than the real value, by the factor of the buffer (4.5% of the total capacity).
A 82.1 kWh battery in model 3 performance most often start at 80.5 kWh or so, according to the BMS.
78.8 kWh would imply a gross capacity of 82.5 kWh, so thats far of. If ot was met capacity it could not go above 78.4kWh, and in most cases it should read 76.9 kWh net. The 77.8 kWh battery, that is 77.8 kWh gross capacity, including the buffer.
The usable capacity is also gross capacity including the buffer. Checked with Scan
my tesla from the BMS, the energy graph and also the rated range at 100% x the constant. They all match, so the usable capacity is quite nice calculated but it also includes the buffer.
This posts can be noce reads about that the buffer is included in the cars reported charged energy: (ots in german
But I pit the link via google translate)
[Wiki] Model 3 / Model Y - Batteriewiki / Akkuwiki
Original post if the link fails:
https://tff-forum.de/t/wiki-model-3-model-y-batteriewiki-akkuwiki/107641/1872?
u=eivissa
/AAKEE
But I pit the link via google translate)
[Wiki] Model 3 / Model Y - Batteriewiki / Akkuwiki
Original post if the link fails:
https://tff-forum.de/t/wiki-model-3-model-y-batteriewiki-akkuwiki/107641/1872?
u=eivissa
/AAKEE
It's also made more confusing by the fact there's a top-end and low-end buffer, and it's also not always 4.5%, and you can keep driving past 0% even though you're not supposed to, so what is usable is really fuzzy. The whole thing is kind of a mess and Tessie tries to make the best thing possible out of it. For lack of a better option, we use what the car reports for your 0-100% energy. I dream for a global standard and to be able to provide a breakdown!
When the car reports charging from 0-100%, the buffer is included in that number. So, the energy is exaggerated by the buffer number (4.7%, as in 1/0.955). This means, using this number as the base for the calculations, we get the gross capacity, including the buffer.
Checks between the energy graph energy, rated consumption x rated range and scan my tesla show that tih is the case. If it was not so, you still would need to reduce the usable capacity with 4.5% as is is 4.5% too high.
Tesla do not use top end buffer.
The battery cells Tesla use (Panasonic NCA) follows the branch standard of 100% SOC = 4.20V/cell, 2.5V/cell = 0%.
96cells in series gives 403.2V at 100%, and 241V at 0%..
See max- and min pack voltage below. (Data from the BMS). Also see the pack voltage on the lower picture.
100% is 100% per the bransch standard, there is no room for any top buffer.
Tesla use a limit for the displayed range thats the EPA number, and in several vehicles this range limit is reached before a new fresh battery is full (Named degradation treshold here on TMC, after @AlanSubie4Life’s term for this). In many cases the ”margin is about 2%.
I do not know is you possibly refer to this as a top buffer?
The bottom buffer that is 4.5% below the 0% on the screen is supposed to be able to drive on. In the EPA rating only energy that is available to the end user can be used to create the EPA range. Tesla use the whole battery from 100% to 0%, so there is no real ”protected buffer”.
It is supposed to be like this, otherwise Tesla would have to need to state lower range.
In plain text we could say that Tesla use no buffer but they use a spare capacity below 0% on the screen, like most vars have a few liters below 0km on the fuel gauge.
(Scan my tesla app round some numbers varying with ios etc, and the terms is chosen by SMT vendors i think.)
The buffer is 4.5% at all times.
From my recent logs (my logged data use better resolution than the mobile apps, so its easer to se the 4.5% relationship:
Nominal Full Pack: 78.88kWh, and the Buffer 3.55kWh
Nominal Full Pack: 78.38kWh and the buffer 3.53kWh
(I have a lot of datapoints, but I took two as an example.)
Below a screenshot from my Model 3 Performance 2021. It has The Panasonic 82.1 kWh battery.
Note pack voltage, this is just before disconnecting the charging cable at 100%. Balancing still was going on, but I didnt wait for it.
We can see the nominal remaing is 82 kWh. Of that is 3.7kWh buffer, and usable 78.3 kWh.
Of all energy (82.0), there is 3.7kWh buffer and the rest (78.3) is usable.
Here’s another with 0.39% SOC:
For the 82.1 Panasonic pack, most cars start at about 80.5kWh according to the BMS (nominal full pack value) and full charges give about the same for the nominal remaining.
The usable new capacity can barely be above 78.3 kWh for this pack ( asi 95.5% of 82.1 is 78.3 and more or less no one have numbers as high as mine). As it mostly hits 80.5kWh, 76.9kWh would be a sort of valid point.
From the app users view, I would say that the initial capacity tha is used for calculations of the degradation should not be lower than what is needed to cover the EPA range the owner did pay for.
(My pack is not the average pack in this, mostly becuase it has been used wit the low SOC strategy, that preserves the pack much better.)
I made a misstake in the above, too late to edit. ( @AlanSubie4Life found it, thank you!
)When the battery has a capacity above that limit (degradation threshold), each km or mile will have a higher energy content and the full range will be reached at 100%.
When the battery capacity have degraded to the trehshold, the energy content will stop decreasing and stay fixed and the range will start to drop with further degradation.
Very informative! Just looking at your numbers, I was wondering does the amount of Regen relate to your general topography? So, that someone living in a hillier area would have higher Regen relative to the total than someone living in a geographically flatter area? Seems intuitively to make sense, but I was just wondering if that is indeed the case, more so, than any driving style influence.
The reason I ask, is I know my data shows Regen to be about 25% of Drive total, but I live in a hilly area, and I try not to regen more than braking to a stop, since I think that's an inefficiency. Anyway, just wondering.
Okay, found it:
I'm showing way higher percentage of Regen relative to Drive total, and I presume that's because of my topography, as opposed to my driving style, or at least I hope so!
I live in the northern part of Sweden but its fairly flat. There are a lot of smaller mountains but the roads go mainly around them. In general, the 10% regen or so seems very standard in Sweden when we look at SMT screenshots.
I would guess @eivissa has about the same as well in Germany.
My gut feeling is that your 25% is the outlier
I also ”weigh” the regen mostly to get a comfortable deccelerstion just as any other car. My ’21 doesnt have the regen amount settings btw.
Interesting thought. I live in the Mid-Atlantic, in what most people would describe as gently rolling hills in Virginia's western Piedmont. My Regen percentage is notably higher than yours, Ken.
Curious as to why you think of Regen to be inefficient? I'm just the opposite - I'm disappointed every time I have to touch the brake pedal. I actually think the one-pedal driving that Tesla's high Regen affords might be its most compelling feature. I come from the world of high performance motorcycles, with high compression engines, which have substantially more engine braking than typical ICE motors. That high compression allows one to manage the throttle in a much more nuanced fashion than the typical engine-brake-engine kind of transition.
My Tesla is the first car I've ever driven that lends itself to that kind of driving. I'm completely smitten by it.
As I may have mentioned, I think using regen for braking is a great feature; but driving smoothly is best for efficiency, so you want to minimize the stop-start driving style as much as possible; so higher regen figures "might" indicate a less efficient driving style, unless you live in a hilly area where you're going to naturally get more regen due to lots of downhills, etc. So, I was trying to figure out if my higher regen %age was due to inefficiency or just topography.
Basically, we don't know if a high regen number is good or not, without context, so that's why I asked aakee about his topography.
I supposed one could intuit the answer by looking at the car's total driving efficiency, to decide whether the regen number was good or not. That is, if you had a bad driving efficiency figure, but high regen, then maybe one's driving style was too stop-n-go, while if you have a good driving efficiency figure and high regen, then it's likely due to topography. That sort of thing.
Basically, we don't know if a high regen number is good or not, without context, so that's why I asked aakee about his topography.
I supposed one could intuit the answer by looking at the car's total driving efficiency, to decide whether the regen number was good or not. That is, if you had a bad driving efficiency figure, but high regen, then maybe one's driving style was too stop-n-go, while if you have a good driving efficiency figure and high regen, then it's likely due to topography. That sort of thing.
A high regen number of course depends on the conditions. For the same conditions a high regen should be good as it saves energy and also reduces the mean cycles size. Less energy on each trip = smaller cycles.
High regen number vs high regen power...
I have always used limited regen power in most deccelerations, not released the pedal completely. Having high regen (like 85kW) on a cold battery didnt feel nice in the "engine/motor ears" so I have reduced it. Having the screen with the battery power in front of the steering wheel sure helps seeing the unnsessesary high regen power. I think it was about one year ago when Tesla reduce the regen power with cold battery or high SOC, that felt good in the lithium heart.
To high regen power vs SOC or cell temp probably wears, but high regen number for energy wont ever be bad as long as the regen power is not too high, ringt?
Aye, I agree that lack of smoothness ought to translate into less vehicle efficiency. In my case, I'm typically above 100%. I'm not sure why. I'm certainly not a cautious, slow driver favoring Chill Mode. Quite the contrary... I still debate purchasing the $2K Acceleration Boost upgrade. But I do make extensive, routine use of Regen braking and have brought much of my motorcycle throttle-control philosophy over to the Tesla.
I couldn't agree more on the use of Regen with a pack at even moderate temps. Depending upon how much deceleration I need, I often will release the throttle pedal completely, but although max Regen is spec'd at 85 kWh, I've never seen more than about 50-55 kWh or thereabouts. I'm guessing you'd have to be coming down from a pretty high rate of speed to generate all the Regen the car is capable of.
Anyway, I should say that I LOVE, LOVE, LOVE Regen when the pack is nice and warm. If the pack is even moderately cool, I don't like Regen at all (and will modify my driving style to avoid it).
Golf8621204
Member
I was previously on this forum quite a bit during the order and waiting stage and just wanted to update everyone with how the car has been.
So overall, I have had only some minor issues and 0 service appointments.
The hood (frunk) received an AWFUL paint job. Interestingly enough, the rest of the car is absolutely fine.
One day I went into the app and tried to get it addressed, but it seemed overly complicated with having to send pics, get Tesla approval, find an approved shop, drop it off for who knows how long, etc. It was just a process I didn't want to get involved in, so I decided to live with it.
The paint was constantly chipping, and still does from time to time, although not nearly as much. Looked like little white specs on the hood. I'm no expert, but it appeared to be extremely thin paint and super thin clearcoat.
So I've fixed it as best I can. I have previous work experience in manufacturing in the paint department so I'm basically doing as good a job as I'm going to get through Tesla without all the aggravation. Long story short: Do not get the black paint unless you want to hand wash frequently, at least once or twice a week minimum, and are fairly knowledgeable with how to detail cars. It's a very, very cheap paint job, in fact, the worst of any car I have EVER owned. In fact, it's FAR WORSE than my 2006 Chevy Cobalt's black paint and that car was sub 20k brand new. I also would not recommend the white interior, as it shows absolutely everything and requires a lot of cleaning and maintenance (I eat a lot in my car, and drink coffee a lot, so it was a mistake on my part). Something as small as a sesame seed is very noticeable.
There is also a scuff mark on the driver's door panel and the middle pillar interior panel, likely caused by the production operator banging the seat on everything before finally getting it seated and installed. I live with it. Awesome car otherwise. I consider myself fairly lucky so far.
As far as the battery goes:
I did a very simple method yesterday of trying to "regain" some lost Range. After 16k miles my total Range at 100% finally changed and went from 358 to 352.
Long story short: it was a waste of time, but here's what I did. I also don't use any third party apps.
I use about 10% state of charge each way for my commute, or 20% a day. I usually charge with my wall connector daily and charge it for say 90 minutes right before I leave.
So instead of daily charging, I let it go down to about 10% and pulled into a local Supercharger. Cost 32 cents per kW. (I could have charged at home, but I need a fast charge as I had plans later).
So when I started the test, I had 352 miles of range. When I charged all the way to 100%, it still said 352 miles of range. Supercharger said charge complete. But it was still charging at about 9kW.
So apparently my BMS was spot-on, even though I didn't go below 50% state of charge for quite some time. And I only went down to around 10% one other time on a road trip.
I completely top charged the pack and waited another 40 minutes or so for the Supercharger to finally shut off and say 0 kW. By doing this, I only ended up gaining 1 mile for a total of 353 miles.
Moral of the story: Don't waste your time doing what I did! If you're total mileage recalculates between 1 and 2%, it's likely accurate.
So I lost 5 miles of range in 9 months of use and 16k miles. Certainly normal and of no concern.
Just wanted to share for any current or future owners!
So overall, I have had only some minor issues and 0 service appointments.
The hood (frunk) received an AWFUL paint job. Interestingly enough, the rest of the car is absolutely fine.
One day I went into the app and tried to get it addressed, but it seemed overly complicated with having to send pics, get Tesla approval, find an approved shop, drop it off for who knows how long, etc. It was just a process I didn't want to get involved in, so I decided to live with it.
The paint was constantly chipping, and still does from time to time, although not nearly as much. Looked like little white specs on the hood. I'm no expert, but it appeared to be extremely thin paint and super thin clearcoat.
So I've fixed it as best I can. I have previous work experience in manufacturing in the paint department so I'm basically doing as good a job as I'm going to get through Tesla without all the aggravation. Long story short: Do not get the black paint unless you want to hand wash frequently, at least once or twice a week minimum, and are fairly knowledgeable with how to detail cars. It's a very, very cheap paint job, in fact, the worst of any car I have EVER owned. In fact, it's FAR WORSE than my 2006 Chevy Cobalt's black paint and that car was sub 20k brand new. I also would not recommend the white interior, as it shows absolutely everything and requires a lot of cleaning and maintenance (I eat a lot in my car, and drink coffee a lot, so it was a mistake on my part). Something as small as a sesame seed is very noticeable.
There is also a scuff mark on the driver's door panel and the middle pillar interior panel, likely caused by the production operator banging the seat on everything before finally getting it seated and installed. I live with it. Awesome car otherwise. I consider myself fairly lucky so far.
As far as the battery goes:
I did a very simple method yesterday of trying to "regain" some lost Range. After 16k miles my total Range at 100% finally changed and went from 358 to 352.
Long story short: it was a waste of time, but here's what I did. I also don't use any third party apps.
I use about 10% state of charge each way for my commute, or 20% a day. I usually charge with my wall connector daily and charge it for say 90 minutes right before I leave.
So instead of daily charging, I let it go down to about 10% and pulled into a local Supercharger. Cost 32 cents per kW. (I could have charged at home, but I need a fast charge as I had plans later).
So when I started the test, I had 352 miles of range. When I charged all the way to 100%, it still said 352 miles of range. Supercharger said charge complete. But it was still charging at about 9kW.
So apparently my BMS was spot-on, even though I didn't go below 50% state of charge for quite some time. And I only went down to around 10% one other time on a road trip.
I completely top charged the pack and waited another 40 minutes or so for the Supercharger to finally shut off and say 0 kW. By doing this, I only ended up gaining 1 mile for a total of 353 miles.
Moral of the story: Don't waste your time doing what I did! If you're total mileage recalculates between 1 and 2%, it's likely accurate.
So I lost 5 miles of range in 9 months of use and 16k miles. Certainly normal and of no concern.
Just wanted to share for any current or future owners!
So yesterday I drove enough to use the numbers;
Car displayed + 24 kWh*
Range before charge: 119km
Range after charge: 270 km
Delta: 151 km
Delta energy 151 x 158.77 x0.955 = 22.7 kWh
Nominal remaining before charge 21.8 kWh
Nominal remaining after charge 44.4 kWh
Difference: 22.6 kWh
Was checked ~ 3hrs after charging complete, so a slight loss is probable (rated range has reduced 0.7km so 0.1kWh more is probable). Nominal remaining did increase about 22.7 kWh as well, just as the delta energy calculated by km x the constant.
*What we see is that the available energy put inside the battery is 22.7kWh ant the car reports 24 kWh. According to both Teslafi and Teslalogger, that saves Scan My Tesla Data, it was added 23.83 kWh that the car dispayed rounded to 24kWh.
If we reduce the reported charged number by the buffer we get 23.83 x 0.955 = 22.76 kWh, not exactly spot on this time, probably some rounded numbers but close enough to see two things:
-using “added energy” will make a higher number than the usable energy added in the battery. The difference is 4.5%, of the buffer size.
-If we charge 0-100% the charged number shown by the car will be the total capacity of the battery included. Using the added energy as the base for capacity calculations will include the buffer.
Taken from the description in the official vendors thread.
(Below just for common interest, and about the efficiency of charging that has been recently discussed):
Electric meter mounted before WC:
66.27 - 41.17 = 25.1 kWh, so efficiency for me 22.6/25.1 = 0.900, 10% losses.
Teslafi, that is taking the “energy added” from the car (which includes the buffer):
| Used:25.16 kWh Added: 23.83 kWh Efficiency: 94.7% |
Shows about 4.5% too high efficiency as the buffer is “included” but not actually delivered/charged.
(Also a slight delta in “used 25.16 kWh” as my new electric meter approved for selling electricity shows 35.10 kWh. Its mounted directly before the WC. Nothing else on that line)
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