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

[AlanSubie4Life]

Here are some more details. I received the vehicle on 12/31/19 and have 6000 miles on it. I have 18 inch wheels and do not use the aero covers. I also mainly charge at home (120v) since March when I became a full time remote worker because of covid-19. Previous to that most charging was done at work via free chargepoint. I have only have supercharged about 5 times.

Regarding my commute, it is actually sea level to 3500 feet then back down to sea level. I don't have nearly as many dots when I charge to 85%

All seems normal. Your capacity loss is on the high side, but also not unusual. It could pop back a few miles and then it would seem totally normal.

Regen dots are normal. Would have to see a picture at a specific state (temp/miles/etc.) to see whether it seems weird. But probably fine.

 

[giantshark18]

All seems normal. Your capacity loss is on the high side, but also not unusual. It could pop back a few miles and then it would seem totally normal.

Regen dots are normal. Would have to see a picture at a specific state (temp/miles/etc.) to see whether it seems weird. But probably fine.

Thanks for the info. Here is a pic of the dots. It was 71 degrees at the time.

 

[AlanSubie4Life]

Thanks for the info. Here is a pic of the dots. It was 71 degrees at the time.

Yep, this is 100% normal. Your battery is at 99%. No problems! As long at it works for you, 80% is a good daily charge level, since it will allow you full regen, until temperatures drop into the 50s (approximately). 90% (or more) is slightly annoying since you'll have limits on your regen, even when it's warm.

Your BMS is currently showing you have lost ~7.5% of your capacity (as I said, it's possible a couple % here could pop back, but I'd say minimum you've lost about 5%, and it's most likely not a BMS "estimation error"). This is a fairly normal result - but on the high side, as I said. It's likely just luck of the draw.

298/322 = 92.5% (This calculation works for 2020 models well, but for 2018/2019 models, capacity loss estimations requires a small correction to the ratio. For example, 290rmi on a 2019 would be approximately 290rmi*245Wh/rmi / 77.6kWh = 91.6%, not 290/310 = 93.5%)

 

[Am12345]

Great point! I forgot we had that info! It does indeed imply 210Wh/mi for the charging constant.

This means my table is wrong for the SR (2019) (EDIT: Note this is an SR 2020, which is not in my table - so the table is actually correct for SR2019), but I'm not surprised by that - the 2019 SR vehicles precede the constant change for the SR+. For sure those older vehicles had this energy graph show 219Wh/rmi (not 210Wh/rmi). That is without a doubt (documented elsewhere here). (I guess technically we never had a picture from the SR, but we had the energy graph pictures from the SR+. As I said, data on these vehicles is rare, so it has always been a confusing situation.)

HOWEVER, interesting what this implies -> the SR at one point did have 220 miles of rated range with a constant of 219Wh/rmi. 48kWh of energy, compared to 50kWh extracted by Tesla in the EPA test - very much in agreement.

Now that the constant is 210, that means the un-degraded range would have been: 220rmi(old)*219Wh/rmi(new) /210Wh/rmi(new) = 229rmi (new).

EDIT: Looks to me like 2019 SR had 220 rated miles, constant 219Wh/rmi, while the 2020 SR had 229 rated miles, constant 210Wh/rmi (see below for a more confusing possibility).

So that means he actually has:

206rmi (new) / 229rmi (old) => 10.1% loss of capacity.

All makes sense now. Also all his pictures above make sense.

I agree he likely has only: 206rmi*210Wh/rmi*0.955*0.99 = 41kWh available to be extracted (not including the buffer).

As compared to 45.6kWh when new (229rmi*210Wh/rmi*0.955*0.99 - or 220rmi*219Wh/rmi*0.955*0.99).

Still, a relatively normal (somewhat high, but within the normal distribution - probably 2.5-3 sigma or so) capacity loss. Something like 1st to 5th percentile I would guess.

Seems like I need to add a line to my table for the SR 2020 (I did not know it existed!).

Thanks for the reminder about this. I'm rusty! Forgot that this is the easy way to get the constant...

EDIT:

For @supraphonic - what was your rated miles when new?

If it was 220 rated miles, that's hard to square with all of this. It is possible for them to use a lower constant and still show 220 rated miles, but they have to do some initial energy inflation of each rated mile to hide the "extra" capacity (so effectively when new the constant is much higher). Note this is my own theory and we have no evidence of it (it's hard to get a hold of).

It wouldn't change the capacity loss though (yes, confusing - the initial energy inflation of rated miles on new vehicles IS confusing). It's almost certainly about 10% for @supraphonic.

hello there i got the SR in March 2020 and double checked the email from sales associate, it comes with 220 rated miles, hopefully this helps.

i am at 206 mi at 100% after 5000 miles, i was at 212 about 2000 miles ago. Im afraid this is some constant degradation im going to continue to see (-6 miles every 2k miles), or does it flatten out after a while?

very similarly to the post above, i have NEVER seen my actual odometer miles go over 150 miles, and i have done long trips ( wh/mi always average less than 270) and of course they like to say “its all normal”. I personally think the rmi displayed is some BS,I would like for them to take it out for a day and try to get within 15 miles of the rated miles displayed at the time.

 

[Raechris]

Don't worry about degradation, it levels out after the first year. My MS75D never showed it's rated mileage but is only down 3% from its starting point or 7% from its rated mileage.
As far as miles, the car will achieve miles claimed but it also takes electricity to run car systems from MCU to power steering, sentry mode to sleep mode and therefore daily trips will not add up to rated miles driven.
Wh at 270 per mile sounds high for your car. My car is rated at 286 and my long term average is about 270.

 

[pl8dlikafiddle]

hello there i got the SR in March 2020 and double checked the email from sales associate, it comes with 220 rated miles, hopefully this helps.

i am at 206 mi at 100% after 5000 miles, i was at 212 about 2000 miles ago. Im afraid this is some constant degradation im going to continue to see (-6 miles every 2k miles), or does it flatten out after a while?

very similarly to the post above, i have NEVER seen my actual odometer miles go over 150 miles, and i have done long trips ( wh/mi always average less than 270) and of course they like to say “its all normal”. I personally think the rmi displayed is some BS,I would like for them to take it out for a day and try to get within 15 miles of the rated miles displayed at the time.

Degradation does flatten out overtime. Follow good charging and storage practices (if you’re not driving much) and it’ll limit your degradation. It seems the SR/SR+ cars hover in the 15-25 mile loss range within the first year, then it flattens out. There are some outliers though, but yours seem normal based on others. I think the lowest I’ve seen reported on here is 198 on a 2019 car with 25,000 miles.

As far as your range, depends on your commute and use. You’re not going to get rated miles with consumption of 270 Wh/mi. You’ll need to be less than 218 Wh/mi to get close for an SR.

 

[Am12345]

Yeah I agree my 270wh/mi was conservative. I just checked some old photos and my car system and I average about 229 wh/mi generally.

thanks all for the degradation clarification

 

[pdx_m3s]

18 month update: Charged to 100% for the second time and got 226 miles... so only down an additional 2 miles in the last 6 months. It was also considerably colder this time. Hopefully it's settled in. I'm comfortable with a 5-6% loss.

 

[Teefal]

Skimming through this thread, I'm wondering if all of you are leaving it plugged in long enough for a good long sleep (3-4 hours, no sentry, no external apps) and starting from a variety of SOCs. I read this was the best way to calibrate the BMS and have started to see results after a week or two. (Important for 3s and Ys)

In other words ... is it actual degradation, or just bad BMS calibration?

 

[pdx_m3s]

In other words ... is it actual degradation, or just bad BMS calibration?

Yes.

 

[AlexP]

My M3 SR+ purchased on 9/9/2020, currently 1027 miles, is showing a range in the app of 241@100% and 217@90%. I have not supercharged it yet.

That's a 3.6 loss in 2 months. Is this early range loss considered normal?

 

[pdx_m3s]

My M3 SR+ purchased on 9/9/2020, currently 1027 miles, is showing a range in the app of 241@100% and 217@90%. I have not supercharged it yet.

That's a 3.6 loss in 2 months. Is this early range loss considered normal?

Degradation is logarithmic, so yes it’s normal to see higher degradation early on.

 

[MarsOrBust]

Tesla charging recommendation and not necessarily best for battery from what I read.
Plug it in every time and set limit to 90%

What is best for the battery in the hot summer?
Set limit to 80% and plugs in after car has been stopped for a couple of hours after a drive?

 

[Rene Speel]

Hey guys,

Can some of you shed some light on a question I have. I bought my m3 LR dm in november 2019. My max range as stated in the app (and car) read 495 kms. One year later I am down to 440 km. Is that normal? Seems to me like a battery degradation of approx. 10% (and november last year the weather was colder if I recall correctly). Anybody familiar with this?

thanks, René

(moderator note: moved posts to existing thread on range loss over time)

 

[chdavis]

I have the same on my 2020 M3P with 25k km. I only have 3% degradation on my 2017 Model X 75 after 100k km so it's really frustrating

 

[XLR82XS]

What is best for the battery in the hot summer?
Set limit to 80% and plugs in after car has been stopped for a couple of hours after a drive?

Just plug in it whenever possible - per the owners manual. Disregard temperature.

 

[FUNco]

Okay my Mod. 3 only says 294 fully charged. My problem is I drove on free for 50 miles to test it. No AP driving speed limit i used 32% of my battery. I was wondering why it always wants to be plugged in.

 

[SkittlesCA]

Long range M3, 10 months old with only 3200 miles. Because of virus it's only been used on in town surface streets. Since I had no reason to, I've never checked the range before now. So, I charged it up to 100 percent and it only registered 300 miles range. Do I have a problem or is it because of only used for short trips?

(moderator note: Moved to existing master thread on this topic)

 

[ucmndd]

MASTER THREAD: Range Loss Over Time, What Can Be Expected, How to Maintain Battery Health

Get to reading.

Or, alternatively, cut to the chase - you don’t have a problem.

(mod note: moved post from a separate thread to the master thread. post existed before move)

 

[AlanSubie4Life]

Long range M3, 10 months old with only 3200 miles. Because of virus it's only been used on in town surface streets. Since I had no reason to, I've never checked the range before now. So, I charged it up to 100 percent and it only registered 300 miles range. Do I have a problem or is it because of only used for short trips?

No problem, range loss is normal and expected even with minimal driving. You didn't specify which wheels you have, but if you have 19" this would be extremely normal (304rmi -> 300rmi). If you have 18" wheels you're likely doing below average, but it's not an unusual situation at all (322rmi -> 300rmi).

If you do have 19" wheels, and want to feel better, swap them to 18" in the wheel configuration menu! (Just kidding, don't do this, it'll screw up your trip planner estimates as long as you have the 18" selected.)