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

[Candleflame]

A little update, ScanMyTesla was showing my battery capacity to be 68.1kWh (from 78.2kWh). It varied a bit according to charges and was always oscillating between 68.1 and 68.5).
I charged to 100% and let the car sleep for a while. Over the course of the week I got it down to 15% driving around.
I drained it to below 5% by putting the heater to the max and having a door opened, this was using over 8kW (was surprised on high how that could go)
I then let the car sleep over over half a day at that SoC.
Then charged to 100% and let the car sleep again for a while.
Battery was now showing 70.1kWh

After about 4 90%->60% cycles, capacity is now showing 70.4kWh 461km , which is the most my car has shown since upgrading to 2020.44.15 back in November where all of a sudden range went down 20km.

So I'm back to a 7.8% battery degradation (According to initial estimated range of 500km), and 10% if comparing from 78.2kWh.

Dont think anything to do with you. I have also noticed paradoxical calibration ( i.e. decreased range by 1% but increased displayed range by 0.5km) after going into park despite the car cycling just around 60%. Must all be software.
My rated extrapolated range has gone up by like 3kms last few days. Gonna do a higher charger on the weekend and then read out battery capacity with smt and post here

Funny how you arent the only person who got some range back. Must have been the last softwareupdate. I probs havnt recieved a big kwh boost like you but then i also havnt cycled my battery heavily. So may just he new softwareupdate from a week ago which needs some new ovc readings....

 

[jyavenard]

Funny how you arent the only person who got some range back. Must have been the last softwareupdate. I probs havnt recieved a big kwh boost like you but then i also havnt cycled my battery heavily. So may just he new softwareupdate from a week ago which needs some new ovc readings....

I haven't done the last software update yet. I've been on this for over a month now.

Also, I'm not talking 1 or 2km increase in range, but over 25km

 

[Candleflame]

I haven't done the last software update yet. I've been on this for over a month now.

Also, I'm not talking 1 or 2km increase in range, but over 25km

Maybe i get 25km too hehe. Need to do some proper cyceling

 

[jyavenard]

Maybe i get 25km too hehe. Need to do some proper cyceling

you should, our cars are pretty much identical.

 

[AlanSubie4Life]

A little update, ScanMyTesla was showing my battery capacity to be 68.1kWh (from 78.2kWh). It varied a bit according to charges and was always oscillating between 68.1 and 68.5).
I charged to 100% and let the car sleep for a while. Over the course of the week I got it down to 15% driving around.
I drained it to below 5% by putting the heater to the max and having a door opened, this was using over 8kW (was surprised on how that could go)
I then let the car sleep over over half a day at that SoC.
Then charged to 100% and let the car sleep again for a while.
Battery was now showing 70.1kWh

After about 4 90%->60% cycles, capacity is now showing 70.4kWh 461km , which is the most my car has shown since upgrading to 2020.44.15 back in November where all of a sudden range went down 20km.

So I'm back to a 7.8% battery degradation (According to initial estimated range of 500km), and 10% if comparing from 78.2kWh.

A decent recovery, and fairly typical I think.

I'm probably up about 1kWh since six months ago, too. (No idea exactly; don't have SMT, have to rely on the 100% charge results, and I disconnected Stats a while back so going from memory on my minimum.) Hard to pin all the changes on the temperature, software updates, modified charging regimen, road trips, etc. Right around 70kWh (286 miles) now.

Also, I'm not talking 1 or 2km increase in range, but over 25km

More like 15km, right? (2.3kWh/152Wh/km = 15km). Just based on your max and min numbers mentioned. Maybe you saw a lower number but did not have an SMT value.

Anyway, pretty good.

 

[jyavenard]

A decent recovery, and fairly typical I think.

you mean typically overall or because of the 100-5% cycle?

More like 15km, right? (2.3kWh/152Wh/km = 15km). Just based on your max and min numbers mentioned. Maybe you saw a lower number but did not have an SMT value.

I went down to 441km, and today at 463km.

 

[AlanSubie4Life]

you mean typically overall or because of the 100-5% cycle?

Typical overall. I’d be surprised if you gained much more. 3kWh is a large error on the estimate (though quite possibly a large part of that was not an error and reflected imbalance or something)! I generally expect errors to be less than half of the buffer size, for no particular reason. Presumably errors can occur in either direction, though they probably bias the estimate to the low side.

 

[Candleflame]

you should, our cars are pretty much identical.

i mean it IS highly unusual how both of our cars decided to get some range back at the same time. almost like its been programmed in. it has nothing to do with the weather - i live in the tropics...

 

[jyavenard]

i mean it IS highly unusual how both of our cars decided to get some range back at the same time. almost like its been programmed in. it has nothing to do with the weather - i live in the tropics...

Maybe they were born within a few minutes of each other and have established on close siblings relationship. They feel each other.

 

[AtticusRex]

40,000 miles on our LR and it charges to 254@80% and 284@90%. I’m happy

16,000 miles on my LR and it charges to 267@90%. I'm losing a little over 1 mile per month.

 

[JJbell]

I know there are PLENTY of forums on this, but everything I have read is just people arguing about mechanical engineering and physics and no conclusion is ever drawn that I can see.

I am about to buy a used 2018 tesla Model 3 and I DO NOT have access to charge at home. My landlord most likely will not install a charger (i know him). I am in this place for 11 months and I do about 200 miles a week in driving. If I supercharge this LR AWD model 3 once a week will it degrade the battery to an amount that is significant enough to care?

 

[jjrandorin]

I know there are PLENTY of forums on this, but everything I have read is just people arguing about mechanical engineering and physics and no conclusion is ever drawn that I can see.

I am about to buy a used 2018 tesla Model 3 and I DO NOT have access to charge at home. My landlord most likely will not install a charger (i know him). I am in this place for 11 months and I do about 200 miles a week in driving. If I supercharge this LR AWD model 3 once a week will it degrade the battery to an amount that is significant enough to care?

There is no "final conclusion", Threads with 100+ pages should make that clear. I dont understand your concern, honestly, because you are looking at a used vehicle so you already will have zero clue how it was treated (charging wise) before you got it.

You likely will be supercharging every 3 to 4 days, not "once a week" like you think, for that mileage driven, and whether it will matter or not in the long term (several year) health of the battery enough to car is debatable. Whether its "no difference" or "A few miles difference", its not likely to be 20s of miles of rated range difference.

 

[JJbell]

There is no "final conclusion", Threads with 100+ pages should make that clear. I dont understand your concern, honestly, because you are looking at a used vehicle so you already will have zero clue how it was treated (charging wise) before you got it.

You likely will be supercharging every 3 to 4 days, not "once a week" like you think, for that mileage driven, and whether it will matter or not in the long term (several year) health of the battery enough to car is debatable. Whether its "no difference" or "A few miles difference", its not likely to be 20s of miles of rated range difference.

Well the used vehicle has 5k miles on it. "Whether its "no difference" or "A few miles difference", its not likely to be 20s of miles of rated range difference."

I think this answers my question. What your saying is: If i do supercharge 1x a week we aren't going to see a degradation of 20+ miles over the long run/

 

[jjrandorin]

Well the used vehicle has 5k miles on it. "Whether its "no difference" or "A few miles difference", its not likely to be 20s of miles of rated range difference."

I think this answers my question. What your saying is: If i do supercharge 1x a week we aren't going to see a degradation of 20+ miles over the long run/

Probably not, but you skipped the part where I said you were going to be supercharging every 3-4 days, not once a week. From a time perspective, unless you are prepared to supercharge every 3 to 4 days (not every 7 days) for this period of time, dont buy the car (and yes I saw that you said you drive 200 miles a week).

 

[JJbell]

Probably not, but you skipped the part where I said you were going to be supercharging every 3-4 days, not once a week. From a time perspective, unless you are prepared to supercharge every 3 to 4 days (not every 7 days) for this period of time, dont buy the car (and yes I saw that you said you drive 200 miles a week).

Can you expand on that? I am new to the tesla community so I don't understand how if I drive 200 miles a week (tops), and the battery has 325 miles of range (charged to 85% weekly is 276), how I would be in a situation where I would need to charge every 3 days? That would assume I would be charging after ~85 miles of use...

 

[jjrandorin]

Can you expand on that? I am new to the tesla community so I don't understand how if I drive 200 miles a week (tops), and the battery has 325 miles of range (charged to 85% weekly is 276), how I would be in a situation where I would need to charge every 3 days? That would assume I would be charging after ~85 miles of use...

Because....

1. That car is used, so wont start with 325 miles range. Tesla "added" range to 2018s with an OTA update, some cars saw it, some did not. Lets assume that a 2018 has the older rated 100% range, after use, of 310 miles.

2. 90% of 310 (its fine to charge to 90% all the time) is 279. Assuming that car still shows a 90% range of 279 (which is actually unlikely), your ACTUAL range is from 90% to about 20-30%, because no one drives an EV "till its empty". Thats 90% (279) to approximately 30% or 20% (93, or 62 rated miles respectively).

279 - 93 = 186, 279 - 62 = 217. Somewhere between 186 miles and 217 "miles" is what you ACTUALLY will have to use.

3. Miles do NOT tick off on the vehicle at a 1:1 rate, just like most people do not get EPA MPG in their ICE vehicles. Without getting into the weeds on this, someone in the rain (bellvue?) will get no where near that, for example. Short trips, etc change it. On average, you should expect 186 rated miles (with no rain, not in the cold) to be about 140-150 actual miles.

30 miles a day, average, 140 ish miles actual range before charging = approximately 4 days. Reduce all the numbers if you actually decide to charge to 80% like you mentioned (which will have you spend less time at the supercharger, because of the charging taper getting slower as the car charge goes up).

4. None of that has anything to do with any degradation of the battery, which, one should expect to be about 5% or so.

TL ; DR , you will be charging every 3-4 days. The mistake you are making (which is basically) " I only drive 30 miles a day, this car has a 325 mile range, I can charge every 7-8 days and that should be fine, and I should have a buffer doing that" is one many many prospective EV owners make. It even makes people buy the SR+ version of the car sometimes when they say "I can buy the SR+ and charge every 6 days based on my usage" when its more like every 2-3 days.

When you charge at home, none of the above really matters, you just plug in when you want to. When you have to go somewhere to charge, however, you need to plan to do that at most every 4 days, given what you said your commute is, and the fact you live someplace where it rains.

 

[JJbell]

Because....

1. That car is used, so wont start with 325 miles range. Tesla "added" range to 2018s with an OTA update, some cars saw it, some did not. Lets assume that a 2018 has the older rated 100% range, after use, of 310 miles.

2. 90% of 310 (its fine to charge to 90% all the time) is 279. Assuming that car still shows a 90% range of 279 (which is actually unlikely), your ACTUAL range is from 90% to about 20-30%, because no one drives an EV "till its empty". Thats 90% (279) to approximately 30% or 20% (93, or 62 rated miles respectively).

279 - 93 = 186, 279 - 62 = 217. Somewhere between 186 miles and 217 "miles" is what you ACTUALLY will have to use.

3. Miles do NOT tick off on the vehicle at a 1:1 rate, just like most people do not get EPA MPG in their ICE vehicles. Without getting into the weeds on this, someone in the rain (bellvue?) will get no where near that, for example. Short trips, etc change it. On average, you should expect 186 rated miles (with no rain, not in the cold) to be about 140-150 actual miles.

30 miles a day, average, 140 ish miles actual range before charging = approximately 4 days. Reduce all the numbers if you actually decide to charge to 80% like you mentioned (which will have you spend less time at the supercharger, because of the charging taper getting slower as the car charge goes up).

4. None of that has anything to do with any degradation of the battery, which, one should expect to be about 5% or so.

TL ; DR , you will be charging every 3-4 days.

Ok thank you for breaking this down. I appreciate that!

 

[AlanSubie4Life]

Ok thank you for breaking this down. I appreciate that!

I would also check the rated range on the vehicle you are planning to buy. It is an LR AWD so it will display 310 miles for a battery that is above the degradation threshold where capacity loss shows (76kWh for this vehicle). (That is the max on that vehicle.)

So, at about 70-80% SoC, have the seller show you: rated miles remaining, and % SoC, two pictures taken concurrently. (There are a couple ways to do this, one is switching energy display mode on the screen, the other is to use the trip planner to show you rated miles remaining and % remaining on the same screen.)

Anyway:

rated miles / SoC% = max rated miles, approx. This is an estimate but a very good estimate and it is directly proportional to battery health/capacity.

That will probably come in around 290 miles or so. Which would be 6.5% loss (approx).

Buying a used vehicle, you will likely experience slower capacity loss since it is fastest when new, but there are no guarantees.

 

[AlanSubie4Life]

So, at about 70-80% SoC, have the seller show you: rated miles remaining, and % SoC, two pictures taken concurrently. (There are a couple ways to do this, one is switching energy display mode on the screen, the other is to use the trip planner to show you rated miles remaining and % remaining on the same screen.)

On second thought, there is a third way: you could also just have the seller send you a recent screen shot of their phone, like this. Just make sure it is done at a relatively high SOC (in the example, this is done at 91% or so). This picture is captured by sliding the slider all the way to the right, HOLDING, and doing a screen capture (you're looking for the little white numbers within the green area (NOT the big numbers above the battery which show by default) which are the projection to 100% when the slider (the little triangle) is positioned at 100%). This vehicle shows 7% capacity loss (which is actually ~10%, but that is a detail...). You'd just like to avoid a vehicle that shows 260, or even 270 miles, at 100%, or at least use that fact to negotiate down the price if the seller is willing, since it actually does matter a little (6kWh is not nothing...):

Do not assume because the vehicle has only 5k miles on it that the battery will be in great shape (though it might be). It's approaching 3 years old, so you should expect capacity loss even if it has not been used.

Obviously you also have to confirm all this info for yourself, in the vehicle, before you pay for it.

 

[dcm3]

Hey all,

I just wanted to post my experience as a data point and get the group's thoughts on my theory. I have a 2020 model 3 AWD. My charging set up is a HPWC and I charge daily or every other day, with only 1 supercharging session ever. My daily commute used to be fairy short, about 20 miles round trip, and so the battery was typically between 50%-80% all of the time We took my wife's Y for long trips so the 3 has never really seen a long trip. The rated miles started around 310, and I honestly don't recall if I ever saw higher than that after the software bump. However, I did see a fairly sharp decline around 7000 miles on the odometer to a nadir of about 275 miles at 100% (projected at a charge of about 80%) I was mildly concerned about this but due to the car's use as above it wouldn't really affect me at all. Lately my daily commute has grown significantly to 108 miles round trip daily. With this, Ive seen a steady increase in my rated miles up to 305 miles today at 100% (projected).

The other interesting point is my efficiency used to be absurdly high (115-125%) that by stats put me better than 97% of users. With the increase in my rated miles, my efficiency has dropped to around 100%.

TLDR
1. With a large increase in my daily commute my rated miles have increased from 279--->305
2. Efficiency has dropped over this time as well


My question is could a very high efficiency be a clue that there are more rated miles than the battery meter is showing? I realize there are numerous factors affecting efficiency (driving style and weather) but it may provide an interesting data point for those who have low rated miles and are curious if it is a true reading or not

P.S. The weather did get much warmer from when the rated miles were 278 until 305 but I did not see the significant increase until my commute lengthened.