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Range Loss Over Time, What Can Be Expected, Efficiency, How to Maintain Battery Health

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Right, nothing I said contradicts that.

Right. But since the energy capacity doesn’t change, of course, since it can’t (unless a different discharge rate is used where there is a ton of internal loss), if they changed Vnom (for whatever reason) then CAC would have to change (scale) to make sure energy capacity doesn’t. That’s all I was saying.

Anyway based on all the SMT captures obviously the voltage used is about 3.6V per cell, as you say, which does not contradict anything I have said. (This is the time-averaged value of the discharge voltage for the discharge rate at which they define CAC. I think.)
The conclusion should be that (in general) to look at the NFP and not use CAC.
Thanks for the informative and interesting discussion on NFP and the CAC. I get the suggestion for staying with just NFP and that the CAC doesn't bring anything more. Clear, and good points.

One final question around this subject. One term I rarely see used in this forum is State of Health (SoH), although often on some other EV forums. On the web, some articles define SoH as NFP @ time t+n over NFP @ t="0" (allows % apparent degradation to be seen). Others suggest it should combine two parameters, the energy capacity (just defined) together with the current ability of the battery @ time t+n to deliver that power (the CAC?). Quite simply, is this just BS or is there something to keep in mind there?
 
One final question around this subject. One term I rarely see used in this forum is State of Health (SoH), although often on some other EV forums. On the web, some articles define SoH as NFP @ time t+n over NFP @ t="0" (allows % apparent degradation to be seen). Others suggest it should combine two parameters, the energy capacity (just defined) together with the current ability of the battery @ time t+n to deliver that power (the CAC?). Quite simply, is this just BS or is there something to keep in mind there?

State of Health is use by some, but can be discussed how good it is to use by non-battery-engineers.

SoH is most often used as the remaining part of the capacity in percent. Teslas BMS doesnt seem to have this value, but we can calculate it.

If the specified capacity is 77.8 kWh and we have 70kWh remaining, the SoH is 70/77.8 = 90%.

The thing is, battery manufacturers specify the life as down to 80% remaining capacity and the researchers most often test down to 80% or slightly more as the degradation and solid electrolyte interphase start to make the battery unpredictable.
SoH 80% sound really fine but according to the manufacturer and the researchers the battery is starting to reach the end of life.
80% should be expressed to simething closer to 0% to be fair then.

If you use a iPhone you can se the SoH and when youre down to 80% its starting to get tired. You do not have 80% left of the practical life at that time.

CAC is only the estimated amphere hours that the battery can hold so it does not have anything to do with power delivery.
The energy is the interresting part and that is the amphere hours x the mean voltage(nominal voltage).

If we had the cells available one by one, we would be interrested in the energy that the battery can deliver, not really the capacity (”CAC”), as we need to multiply the capacity with the nominal voltage. Another interresting point is the internal resistance, as a increased internal resistance will increase the heat losses during the discharge (meaning more heat released and less energy to the motors). We cannot measure the internal resistance in the whole pack and the BMS doesnt tell us this, as far asI’ve seen.

One further thing about CAC: If you look at a discharge curve showing delivered capacity vs voltage the first thought when I ask where the 50% SOC is positioned probably is in the middle of the capavity. If the cell is a 5000 mAh cell, one would think ”at 2500mAh”.
That is not correct, as the energy delivered is milliamps x voltage. At 100% SOC with 4.2V, the energy delivered from 100mAh is much more than 100mAh at low SOC.

I checked an old picture where my car had 81.6kWh NFP and a CAC of 235 Ah, this points at amean voltage of 3.617V /cell but a recent give me 3.581V so it is not a 100% relation between the NFP and the CAC. Probably something lika my guess some days ago about a ”decending mean voltage” as the battery degrades?
 
State of Health is use by some, but can be discussed how good it is to use by non-battery-engineers.

SoH is most often used as the remaining part of the capacity in percent. Teslas BMS doesnt seem to have this value, but we can calculate it.

If the specified capacity is 77.8 kWh and we have 70kWh remaining, the SoH is 70/77.8 = 90%.

The thing is, battery manufacturers specify the life as down to 80% remaining capacity and the researchers most often test down to 80% or slightly more as the degradation and solid electrolyte interphase start to make the battery unpredictable.
SoH 80% sound really fine but according to the manufacturer and the researchers the battery is starting to reach the end of life.
80% should be expressed to simething closer to 0% to be fair then.

If you use a iPhone you can se the SoH and when youre down to 80% its starting to get tired. You do not have 80% left of the practical life at that time.

CAC is only the estimated amphere hours that the battery can hold so it does not have anything to do with power delivery.
The energy is the interresting part and that is the amphere hours x the mean voltage(nominal voltage).

If we had the cells available one by one, we would be interrested in the energy that the battery can deliver, not really the capacity (”CAC”), as we need to multiply the capacity with the nominal voltage. Another interresting point is the internal resistance, as a increased internal resistance will increase the heat losses during the discharge (meaning more heat released and less energy to the motors). We cannot measure the internal resistance in the whole pack and the BMS doesnt tell us this, as far asI’ve seen.

One further thing about CAC: If you look at a discharge curve showing delivered capacity vs voltage the first thought when I ask where the 50% SOC is positioned probably is in the middle of the capavity. If the cell is a 5000 mAh cell, one would think ”at 2500mAh”.
That is not correct, as the energy delivered is milliamps x voltage. At 100% SOC with 4.2V, the energy delivered from 100mAh is much more than 100mAh at low SOC.

I checked an old picture where my car had 81.6kWh NFP and a CAC of 235 Ah, this points at amean voltage of 3.617V /cell but a recent give me 3.581V so it is not a 100% relation between the NFP and the CAC. Probably something lika my guess some days ago about a ”decending mean voltage” as the battery degrades?
Thanks quite clear!
 
When supercharging i always set the charge range to just below the 'Trip' bar which yields 248 miles. When i drag the setting to the top marker it goes to 280. Bought the car new June 2020. I don't remember ever seeing the range at or over 300. Does it make sense to be down to 280 max range. I plug in my car almost ever time i enter my garage, six or so times a day. Is 280 max charge unusual?
 
...Is 280 max charge unusual?
That depends.

Tesla defines it as normal if your car degradation is within 30%.

[numbers edited begin] Your EPA rating is 322. Losing 30% of it is 97 miles or your battery gauge would show 225 miles.

By that definition, your battery gauge shows that you have 280 which is a lot more than 225 miles, so you are fine. [numbers edited end]

If you are worried about it, what you want to practice is to keep plugging in at 90% as much as possible so that the Battery Management System can calculate the range better.

If you don't do that, the range calculation may be inaccurate but your battery is the same, unaffected: It just bothers owners when they look at the "low" range like "280".

In order to see if your full battery is actually 280 or something other numbers, you need to actually charge your battery fully. It may take a long time for the Battery Management System to calculate the last fraction of the range from 99.999% to 100%. Only when you see the word "complete", then that's the current calculation for the day. It might not be correct if you don't practice charging daily at 90% though.

Remember, sliding to 100% without actually charging 100% is an estimate and it can be wrong until you actually charge it at 100% and plug-in daily for 90% faithfully.
 
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I can't tell you what's "normal", but I will provide another data point: my car is at 46,500 miles and currently shows a maximum range of 298 miles.
LR AWD, very little supercharger usage and I'm a relatively slow driver.
There are lots of threads about battery degradation. You might want to take a look at this one:
 
Does it make sense to be down to 280 max range.
Yes.
Is 280 max charge unusual?
No.
Your EPA rating is 310.
No, it’s a 2020. Vehicle type was not specified but most likely LR AWD. Which would be 322.

If a Performance, it is either 299, 304, or 322, depending on the wheel selection (applies to 2020 Performance only, plus there is a software bug on 2021 Performance which screws up some info if you select different wheels, but should not be applicable here).

So most likely 13% estimated capacity loss which is well within normal, though a bit on the high side (but actual value could easily be 11% which would be completely normal).

This will be moved to the range thread at some point soon, lol.
 
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Thanks for catching that. My mistake for thinking about my own 2018 Model 3 which is 310 miles.
As it turns out if you just use the 322 miles for 2018 it gives closer to the correct answer (actual number to use is 318 for 2018 and 2019, even though the max displayed was 310 for those years). But yes 310rmi is the number to use for 2018/2019 even if it yields a slightly optimistic result.

318rmi*245Wh/rmi = 77.9kWh
 
Good evening everybody, wishing to all of you a wonderful weekend and happy 4th of July, the way our great country deserve. Yesterday, I decide to visit my brother that lives in West Palm Beach, FL. I live in Aventura, Florida. So, using the turnpike, and, according to the GPS, from Aventura to WPB, it is roughly 50 miles up and 50 down. For this purpose I went to the aventura mall tesla superchargers and I charge my beloved T M3 to up to 85%. I went to my brother and back home, and the car consumed 30% and change. Photos will be included. From yesterday until now, the car now has only 23% of battery. Of course I did some errands today.

This is how I feel, I have the sensation that I am doing something wrong or the car has something wrong. I feel that the car is connected three days per week, but when I had my gas car, I only needed to go to a gas station once per week.

I follow your kindly recommendations from my last post, like:

  • completely turn of the A/C.
  • Sentry system's off during the night and also during the day, including when I am driving
  • When I am using the car I try to not to use to much fan speed form the A/C.
Please have in mind that my Tesla model 3 is the one that has long range and dual motor. What do you think is happening? What can I do in order to minimize the battery consumption?

In advanced thank you so much for your help. I know that I am bothering you, maybe too much, but you are the experts. And I am so grateful in advanced for your support. Ty
 
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...I feel that the car is connected three days per week, but when I had my gas car, I only needed to go to a gas station once per week...

You need to break the gasoline habit and adopt your owner's manual:

"Model 3 has one of the most sophisticated battery systems in the world. The most important way to preserve the high voltage Battery is to LEAVE YOUR VEHICLE PLUGGED IN when you are not using it."

Note that the capitalized words are not from me. They came from the owner's manual itself.
 
APRB has a parameter for 'Battery Degradation'. I have done a few cross country trips using 5%. But i recently noticed that my max charge setting for Trip is 280 miles. Would that indicate that my battery degradation is > 5%?
You can ask ABRP to "calibrate" your car and it will calculate your "battery degradation" based upon data it pulls from when you supercharge. Here's mine:
IMG_4810.jpeg
 
...What can I do in order to minimize the battery consumption?...

1. Disable Sentry Mode
2. Disable Summon Standby Mode
4. Disable Mobile Access
5. Disable Data Upload (to Tesla)- click "do not agree"
6. Disable Climate Preconditioning
7. Disable Scheduled Departure.
8. Disable Cabin Overheat Protection
9. Make sure HVAC is off when you leave-Disable "Keep Climate On"
10. Do not use Tesla App or any third-party data-logging apps.
11. Software Update: Standard
 
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Good evening everybody, wishing to all of you a wonderful weekend and happy 4th of July, the way our great country deserve. Yesterday, I decide to visit my brother that lives in West Palm Beach, FL. I live in Aventura, Florida. So, using the turnpike, and, according to the GPS, from Aventura to WPB, it is roughly 50 miles up and 50 down. For this purpose I went to the aventura mall tesla superchargers and I charge my beloved T M3 to up to 85%. I went to my brother and back home, and the car consumed 30% and change. Photos will be included. From yesterday until now, the car now has only 23% of battery. Of course I did some errands today.

This is how I feel, I have the sensation that I am doing something wrong or the car has something wrong. I feel that the car is connected three days per week, but when I had my gas car, I only needed to go to a gas station once per week.

I follow your kindly recommendations from my last post, like:

  • completely turn of the A/C.
  • Sentry system's off during the night and also during the day, including when I am driving
  • When I am using the car I try to not to use to much fan speed form the A/C.
Please have in mind that my Tesla model 3 is the one that has long range and dual motor. What do you think is happening? What can I do in order to minimize the battery consumption?

In advanced thank you so much for your help. I know that I am bothering you, maybe too much, but you are the experts. And I am so grateful in advanced for your support. Ty
Your ICE fills up once a week, so most of the time, it's not full. Your Tesla can leave home each day with a full charge, whatever you consider to be "full". For me, I have a 30mile commute, so my "full" is 60%. I'm plugged in all the time when I'm at home.

More info helps, but from what you said, you started at 85%, drove ~100 miles, used up more than 30%, so you have around 50%. Since then, you've done a few errands and dropped to 23%. No one can tell anything with that amount of data.

It's impossible to say without more data, but you're in Florida. It's hot and humid. You should set your thermostat at a temp that's comfortable, and let the car figure out fan speed, etc.

Don't forget to turn off Smart Summon if you have it, and turn off AC when using overheat protection. That should keep phantom drain as low as possible.
 
...50 miles up and 50 down. For this purpose I went to the aventura mall tesla superchargers and I charge my beloved T M3 to up to 85%. I went to my brother and back home, and the car consumed 30% and change...

That's about right. Before I leave, I make sure I have enough charge plus 100 miles extra.

That means, if my next charger is 210 miles away, I don't leave until the battery gauge says "310 miles".

In your case, you leave at 85% or 263 miles on my battery gauge.

You traveled with a stop in between (my extra reserved miles are for a direct trip with no stops in between) and got back home after 100 miles of travel and a loss of 30% charge or 85-30=55% or that would be 170 miles on my battery gauge.

My battery gauge from 263 down to 170 miles means a loss of 93 miles.

Losing 93 battery gauge miles for actually driving 100 miles with a stop is just too good for me to duplicate. My car has used much much more!
 
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