Rated Range MP3 - Low mileage?

[sonic88]

Hi,

Looking for some advice/thoughts on my 2019 MP3's rated range? Was delivered on Aug 2019 with a range of 310.
It's now a just over a year old, and one thing to note is that I have not driven many miles on this i.e. 3018miles currently.
The current rated range has dropped to 298 i.e. about 12 miles lost ~4%

When i charge, i do so regularly at 90%. I have a few instances tried 100% charges as well, and have always driven the car within 30-40mins at 100% level. The lowest soc I've gone down to is about 8% (~25m).
Have never left the car sitting long (i.e. days) outside the <20% or >90% long; and kept it in the 20%-90% range. Only SuC about 4 times, rest have been either home charging 7kw or non-SuC charges at 50kw.

Having reviewed a few threads on lost of rated range, some folks appear to see the same level of drop, however their mileage is far higher i.e. 10-30k
I know cars of similar mileage to mine (~3k) were probably still getting close to their original 310 i.e. 307-309

Would it be fair to say that my lost is likely due to real degradation based on the age alone, rather than mileage?
Or is it simply due to the lack of driving mileage that the rated range is being skewed?

 

[akenham]

There's a long thread on this subject in the pinned post "How I Recovered Half of my Battery's Lost Capacity".

Your charging pattern sounds very benign and not out of the ordinary so you could be seeing some combination of expected initial range drop and/or the BMS's estimation of range drifting downwards (but the battery actually being better than it currently estimates).

Most sources say that a small reduction in range happens early then stabilizes for a long while - I note that even at face value, 298/310 miles is 96.1%

The BMS estimate gets less accurate when it doesn't get to "see" different states of charge often (see = sits idle for 3h or so at that state of charge without the car using power by being woken / sentry running etc).

Personally, I don't think I'd go out of my way to place the car at different states of charge just to correct the BMS - especially if that meant more/deeper charge cycles or deliberately visiting the extremes (<20%, >90%), but my normal overnight timed charging allows it to fairly frequently sit at 80-90%, at 50% and sometimes at 20-30%. We'll see how that works out.

 

[sonic88]

There's a long thread on this subject in the pinned post "How I Recovered Half of my Battery's Lost Capacity".

Your charging pattern sounds very benign and not out of the ordinary so you could be seeing some combination of expected initial range drop and/or the BMS's estimation of range drifting downwards (but the battery actually being better than it currently estimates).

Most sources say that a small reduction in range happens early then stabilizes for a long while - I note that even at face value, 298/310 miles is 96.1%

The BMS estimate gets less accurate when it doesn't get to "see" different states of charge often (see = sits idle for 3h or so at that state of charge without the car using power by being woken / sentry running etc).

Personally, I don't think I'd go out of my way to place the car at different states of charge just to correct the BMS - especially if that meant more/deeper charge cycles or deliberately visiting the extremes (<20%, >90%), but my normal overnight timed charging allows it to fairly frequently sit at 80-90%, at 50% and sometimes at 20-30%. We'll see how that works out.

I was hoping to still see relatively higher rated ranges despite the low usage; and that the range would be comparable to other cars of similar mileage putting the age aside. However, what it seems to suggest is that the rate range is primarily driven purely from age of the battery regardless of the mileage/usage?

As my usage is very low, at times the car tends to sit over long periods (a few days between drives). Hence the soc just slowly discharges from being idle mostly. I'm not sure if this behaviour is potentially causing the BMS to drift?
I don't have sentry on whilst the car is idle in the garage, so does get to see different soc.

 

[akenham]

I think having sentry on actually stops the BMS getting useful measurements - it needs the battery to settle down without a load so anything that draws from it prevents that. People say about 3h for model 3 (and presumably Y), possibly less for other models

My guess is that your BMS is simply guestimating a low range due to limited opportunities to make useful measurements - if it either never gets to make them (sentry always on) or only at one SOC you'll get increasingly poor estimates. It's reasonable to see a small actual reduction in range - this happens quickly from new - you can look online for what the average is but it seems to be sub 5%.

Your pattern of slow discharge with limited miles and lot of slow sentry consumption could very well be making the BMS estimate drift so that you appear to have a lower capacity - not the same thing as actually having a reduced capacity.

If the low estimate is bothering you and you can do without sentry for a little while (e.g. at home in the garage) you could try:

• Reserve sentry usage for when you're not at home (to my mind this is when you need it most)
• Timed charge the car to 90% and let it sit after completion for 3h without waking (due to using the app / teslafi / opening the door).
• Use the car and again let it sit at a lower state for 3h as above - ideally get down to 30-50% but don't go too low and deep discharge deliberately.
• Repeat this a small handful of times.

If not having sentry will worry you then just use your car and don't worry about it.

Personally, I've got the car sitting under wall CCTV at home so I don't need sentry on except when I'm out (peace of mind for car park damage etc - you can set the car to do "not at home", "not at work" etc). I don't want to overstate this but I also have a mild preference not to run sentry all day because even though it's a slow, shallow discharge I'm still technically consuming a little of my battery's useful life when I don't need to do so - I doubt I'll ever notice whilst I own the car but I'd sooner not waste it as such.

 

[AlanSubie4Life]

The current rated range has dropped to 298 i.e. about 12 miles lost ~4%

Your BMS thinks you have about 245Wh/rmi*298rmi = 73kWh of energy including the buffer.

You most likely started with about 78kWh.

So that's 6.5% loss (it's slightly more than you might think from the ratio of miles, based on a variety of evidence we have about how these things work).

I'd guess for the most part the BMS is correct, but perhaps you could recover a couple % with some change in charging pattern (maybe you could see it bounce to 304 rated miles - might even happen as the ambient temperature changes or on a new software update).

Mostly looks like normal age-related capacity loss to me. Thanks for the datapoint! Nice to see data from very low mileage vehicles.

1 year, 3k miles, 6.5% loss. That's mostly in-line with many people after that period of time - even those who have gone 12-15k miles in that time. I'd say it's very slightly higher capacity loss than I would expect (seems like 302-306 rated miles would be more typical). But I think it depends on exactly where you started with your initial capacity - everyone started at 310 rated miles in 2018/2019, but there is some variability on the energy that the 310 rated miles represents.

 

[Sam1]

Here's mine today - 12 months old, 37,000 miles

 

[AlanSubie4Life]

Here's mine today - 12 months old, 37,000 miles

View attachment 593453

Thanks. Assuming the TeslaFi estimate matches the car when charged to 100%, looks like you are at:

278rmi*245Wh/rmi = 68kWh

So about 13% capacity loss. (Maybe slightly more or less depending on your precise start point.). (Can safely ignore TeslaFi's estimate which is just based on the rated miles ratio.)

1 year, 37k miles, 13%.

Both miles and time seem to matter, of course.

 

[Sam1]

Thanks. Assuming the TeslaFi estimate matches the car when charged to 100%, looks like you are at:

278rmi*245Wh/rmi = 68kWh

So about 13% capacity loss. (Maybe slightly more or less depending on your precise start point.). (Can safely ignore TeslaFi's estimate which is just based on the rated miles ratio.)

1 year, 37k miles, 13%.

Both miles and time seem to matter, of course.

Yeah, mine fluctuate between 12-13% pretty consistently on actual reading in the car. It just needs to hold on around that level until a bigger/better/faster M3P is released lol

 

[mswlogo]

If you are driving that little I think charging to 90% is not a great idea. Despite what Elon says. If you need 90% for a comfortable commute, fine. But if you don’t I think 80% is better.

For the record after 1 year and 10K miles I think my Model 3 lost just a few miles. Supercharged a bunch of times. Including several too 100%. Same on my X. 10k miles 1 year old and it’s down 4 miles. I keep it 80%.

 

[Sam1]

If you are driving that little I think charging to 90% is not a great idea. Despite what Elon says. If you need 90% for a comfortable commute, fine. But if you don’t I think 80% is better.

For the record after 1 year and 10K miles I think my Model 3 lost just a few miles. Supercharged a bunch of times. Including several too 100%. Same on my X. 10k miles 1 year old and it’s down 4 miles. I keep it 80%.

There's obviously a lot of things that go into it... but I equate my battery loss with the car doing pretty much non-stop full throttle launches from stop lights every time I'm in it... and living in a city, there's dozens of those per day.

 

[AlanSubie4Life]

If you are driving that little I think charging to 90% is not a great idea. Despite what Elon says. If you need 90% for a comfortable commute, fine. But if you don’t I think 80% is better.

For the record after 1 year and 10K miles I think my Model 3 lost just a few miles. Supercharged a bunch of times. Including several too 100%. Same on my X. 10k miles 1 year old and it’s down 4 miles. I keep it 80%.

I agree, there's no need to charge to 90%. However, your datapoints here are anecdata and there is no reason or evidence that I'm aware of that shows that 90% actually is causative for this sort of loss. All vehicles have some variability on start energy and you may have lucked out twice, and the OP could be an example of a somewhat lower start point.

Of course, there's no way to go back in a time machine and find out. Agreed that if there is no reason for it, 80% is better. It just may not make any difference, and people should not expect it to.

 

[AlanSubie4Life]

There's obviously a lot of things that go into it... but I equate my battery loss with the car doing pretty much non-stop full throttle launches from stop lights every time I'm in it... and living in a city, there's dozens of those per day.

I think he was referring to the OP. But in your case, it seems that you are making full use of the vehicle. Lots of miles, lots of launches. Have fun! Be safe!

Have to make up for the oil you are saving, by using up tires.

 

[mswlogo]

I agree, there's no need to charge to 90%. However, your datapoints here are anecdata and there is no reason or evidence that I'm aware of that shows that 90% actually is causative for this sort of loss. All vehicles have some variability on start energy and you may have lucked out twice, and this could be an example of a somewhat lower start point.

Of course, there's no way to go back in a time machine and find out. Agreed that if there is no reason for it, 80% is better. It just may not make any difference, and people should not expect it to.

I’m not saying it is. I think we agree because it’s always better to be lower and in this case it would have 0% inconvenience.

I’m just throwing my numbers out there. I rarely launched either Model 3 (P) or X. Both usually in Chill mode.

 

[mswlogo]

There's obviously a lot of things that go into it... but I equate my battery loss with the car doing pretty much non-stop full throttle launches from stop lights every time I'm in it... and living in a city, there's dozens of those per day.

I rarely have such a problem. I rather relax and listen to tunes. I suspect if you launch that often that it’s gonna cost you a lot more than just a bit of range.

 

[Sam1]

Have to make up for the oil you are saving, by using up tires.

Trying to help out the economy when I can! The pandemic has hurt everyone's industry

 

[mswlogo]

Trying to help out the economy when I can! The pandemic has hurt everyone's industry

Not really. Tons of businesses are booming. Tire shops are probably not one of them though.

 

[Sam1]

Not everything posted on the internet is serious

 

[sonic88]

I think having sentry on actually stops the BMS getting useful measurements - it needs the battery to settle down without a load so anything that draws from it prevents that. People say about 3h for model 3 (and presumably Y), possibly less for other models

My guess is that your BMS is simply guestimating a low range due to limited opportunities to make useful measurements - if it either never gets to make them (sentry always on) or only at one SOC you'll get increasingly poor estimates. It's reasonable to see a small actual reduction in range - this happens quickly from new - you can look online for what the average is but it seems to be sub 5%.

Your pattern of slow discharge with limited miles and lot of slow sentry consumption could very well be making the BMS estimate drift so that you appear to have a lower capacity - not the same thing as actually having a reduced capacity.

If the low estimate is bothering you and you can do without sentry for a little while (e.g. at home in the garage) you could try:

• Reserve sentry usage for when you're not at home (to my mind this is when you need it most)
• Timed charge the car to 90% and let it sit after completion for 3h without waking (due to using the app / teslafi / opening the door).
• Use the car and again let it sit at a lower state for 3h as above - ideally get down to 30-50% but don't go too low and deep discharge deliberately.
• Repeat this a small handful of times.

If not having sentry will worry you then just use your car and don't worry about it.

Personally, I've got the car sitting under wall CCTV at home so I don't need sentry on except when I'm out (peace of mind for car park damage etc - you can set the car to do "not at home", "not at work" etc). I don't want to overstate this but I also have a mild preference not to run sentry all day because even though it's a slow, shallow discharge I'm still technically consuming a little of my battery's useful life when I don't need to do so - I doubt I'll ever notice whilst I own the car but I'd sooner not waste it as such.

Hi,

Just to add, whilst parked in the garage (where it mostly is), i don't have sentry activated. So this should give it plenty of time to sleep and do what it needs.
If you see my data points, i do tend to charge to 90% each time. However, i dont have it plugged in at every opportunity (only when i need to charge).

As of my recent post, I have disabled sentry altogether. I've been trying to make an effort to charge to 90% and do incremental discharges (10-20% each time); and then let the car sleep for a good number of hours.
Actually after a 90% charge, i've left it sitting for well overnight (7+hrs sleep with the aim for to do any unbalancing if required) whilst still plugged in.
Thereafter, i unplug and proceed to discharge 10-20% per day or two, and let it sleep after.
Once i hit 20-30% soc, i'll repeat and charge back to 90%.
Have only managed this cycle one time with a current est range of 298mile (probably takes me atleast a week or more to do). Will continue to see how it goes?

 

[sonic88]

Your BMS thinks you have about 245Wh/rmi*298rmi = 73kWh of energy including the buffer.

You most likely started with about 78kWh.

So that's 6.5% loss (it's slightly more than you might think from the ratio of miles, based on a variety of evidence we have about how these things work).

I'd guess for the most part the BMS is correct, but perhaps you could recover a couple % with some change in charging pattern (maybe you could see it bounce to 304 rated miles - might even happen as the ambient temperature changes or on a new software update).

Mostly looks like normal age-related capacity loss to me. Thanks for the datapoint! Nice to see data from very low mileage vehicles.

1 year, 3k miles, 6.5% loss. That's mostly in-line with many people after that period of time - even those who have gone 12-15k miles in that time. I'd say it's very slightly higher capacity loss than I would expect (seems like 302-306 rated miles would be more typical). But I think it depends on exactly where you started with your initial capacity - everyone started at 310 rated miles in 2018/2019, but there is some variability on the energy that the 310 rated miles represents.

Hi,

My UK 2019 Aug delivered MP3 had an est rated mileage of 310.8miles at 100% soc as per my Teslafi data point on 01/12/2019. Unfortunately I don't have any data points prior to 01/12/2019 as I never used Teslafi until then. Also, my first ever 100% soc was carried out on 02/07/2020 giving me 306.94miles (as per Teslafi data point shown). In terms of initial capacity, i'm not sure what that was exactly other than the est mileage captured from Teslafi.

With regards to initial capacity, you mentioned 78kwh. I thought the initial capacity was 75kWh? with a usable capacity of 72.5kWh?
Tesla Model 3 Long Range Performance

According to the avg Teslafi fleet, the similar mileage car to 3k is about 304-305miles. Which i was hoping i'd also get at the very least rather than a downwards trend to 298. Although the compared fleet will lightly be based on newer cars at my mileage. So I guess my range drop may be based on age rather than mileage.

In terms of charging habits, I've started the following:
1) Charge to 90% each time
2) After charge at 90%, leave it plugged in and stationary overnight +8 hours for balancing purposes?
3) Aim to use 10-20% on each drive session, and let it sleep for at least 3hrs thereafter
4) Discharge to either 30-20% before charging back up

For steps 3-4, it may take me a week or more due as i dont tend to use the car every day as such.
But I assume if i let the car sit longer (and it discharges naturally), that this is still ok?

I'm hoping the above may help the car give better rated estimates after a charge? such that my range will increase back up slightly?

Are you recommending that I only charge to 80% instead? I was hoping to try the above for a couple of weeks to see what the effects would be?
Previously from the data points you can see that I've tried 100% soc and drive things down, but there was not much of an effect.

Appreciate any further advice.
Cheers

 

[AlanSubie4Life]

I'm hoping the above may help the car give better rated estimates after a charge? such that my range will increase back up slightly?

I have not found that any of these types of procedures make much difference. You might gain 5 miles or something, but unlikely anything more significant than that.

You should expect a downward trajectory of capacity, hopefully leveling off significantly around 10% capacity loss (280-285 miles), with slower capacity loss from there.

With regards to initial capacity, you mentioned 78kwh. I thought the initial capacity was 75kWh? with a usable capacity of 72.5kWh?
Tesla Model 3 Long Range Performance

If you look at the “Constants” sticky, it provides the link to the Tesla’s EPA testing done in Fremont and the size of the battery in each vehicle.

Tesla extracted 79kWh from the AWD battery, including the buffer.

It’s about 75kWh *not* including the buffer (meaning down to 0 rated miles), when new.

New vehicles when read from with SMT typically show 78kWh (includes buffer).