Possible 35% battery degradation after 57k miles?

[2018_TS_S_P75D]

Hi Everyone, I am a proud second owner of a 2018 Tesla S 75D with about 57k miles. Still not familiar with the car, but the range is not what we expected, as apparently we can only drive about 130 miles on a full charge.
Yesterday my wife drove 65 miles and used 25 kWh, 51% of the battery. That comes to 49 kWh on a full charge, about 65% of a new 75kWh battery.

Is this data accurate? Am I missing something?

I tried to do a battery test health but the button for health check is missing from the Service -> HVB screen.

Thanks

 

[Rocky_H]

Hi Everyone, I am a proud second owner of a 2018 Tesla S 75D with about 57k miles. Still not familiar with the car, but the range is not what we expected, as apparently we can only drive about 130 miles on a full charge.
Yesterday my wife drove 65 miles and used 25 kWh, 51% of the battery. That comes to 49 kWh on a full charge, about 65% of a new 75kWh battery.

Is this data accurate? Am I missing something?

That data may be accurate, but it's irrelevant to trying to figure if there is any degradation of your battery. How far you can end up driving is not a measurement of the energy in the battery. If you drove 170 mph in a hurricane, you probably couldn't drive very far, but that wouldn't be because of degradation of the battery.

You have an S75D. There is a battery meter on the display. In the car's display settings, you can select between "Energy" or "Distance", which will toggle that battery meter from either % or a number called "rated miles". Can you give us a data point on what that shows for both % and rated miles at a certain point by toggling that setting?

 

[2018_TS_S_P75D]

My wife has 65 miles commute freeway / city with not much traffic so she drives 65 - 75 mph on the freeway. I guess that is kind of an average commute. The car uses about 100+ miles of battery on this 65 miles daily drive, so we have to charge the car daily.
My calculation of the battery health come from the % of battery used and energy used. That has nothing to do with range or ride conditions. The car used 51% of the battery, corresponding to 25 kWh. 25 kWh / 51% * 100 = 49 kWh apparent battery capacity, that is about 65% of the battery capacity when new (75kWh). We either see a 35% battery degradation or some data is incorrect.
I believe that 49% left corresponded to 110 "rated miles". What are these rated miles good for I don't know, as we can drive 65 real miles on these 100 rated miles.

 

[gt2690b]

My wife has 65 miles commute freeway / city with not much traffic so she drives 65 - 75 mph on the freeway. I guess that is kind of an average commute. The car uses about 100+ miles of battery on this 65 miles daily drive, so we have to charge the car daily.
My calculation of the battery health come from the % of battery used and energy used. That has nothing to do with range or ride conditions. The car used 51% of the battery, corresponding to 25 kWh. 25 kWh / 51% * 100 = 49 kWh apparent battery capacity, that is about 65% of the battery capacity when new (75kWh). We either see a 35% battery degradation or some data is incorrect.
I believe that 49% left corresponded to 110 "rated miles". What are these rated miles good for I don't know, as we can drive 65 real miles on these 100 rated miles.

How do you know she used 25kwh? Was she averaging 384 wh/mi?

 

[Lasttoy]

There are also other factors. AC on, headlights on. The two drain power, especially since the AC system is 400volts. My 85 uses a different amount everytime. But on the average uses 100 miles for 80 in daytime with AC on 70. But, can you charge to 200 miles or more??? That tells u that battery is ok.

 

[2018_TS_S_P75D]

How do you know she used 25kwh? Was she averaging 384 wh/mi?

yep, 385 Wh / mi

 

[2018_TS_S_P75D]

There are also other factors. AC on, headlights on. The two drain power, especially since the AC system is 400volts. My 85 uses a different amount everytime. But on the average uses 100 miles for 80 in daytime with AC on 70. But, can you charge to 200 miles or more??? That tells u that battery is ok.

AC on, headlights on, music on.... ridiculous that with a car that advertises 256 miles you cannot do 130 and we have to charge daily. We also have an e-golf (38kWh version) with 40k+ on the odometer that pretty much does 100 miles daily (111 advertised) with a few miles left at the end of the day. Also AC and headlights on.

 

[gt2690b]

yep, 385 Wh / mi

interesting.. i just calculated my last 10 trips over 30 miles and compared to my first 10 trips (back in Nov. 2021)... was averaging about 78kWh and now its more like 73kWh ... looks like i've lost just over 6% in 1.5 years (newest trips on top... bottom # is first trip ever) ... u may have a warranty claim

72.86
71.11
71.11
70.00
75.33
73.87
75.65
75.43
75.00
72.73

75.71
78.18
81.00
78.06
76.80
78.18
78.89
78.73
77.62

 

[ucmndd]

yep, 385 Wh / mi

That is insanely high consumption for a 75D and why you're not getting anywhere near rated range. This is the problem you need to figure out / solve. You don't have a "degradation" problem, you have a consumption problem.

For reference, my 2016 75 has averaged 315wh/mi over 170,000 miles.

How many miles does your range display show at 100%? That's really your only customer-visible metric of actual battery degradation.

 

[gt2690b]

That is insanely high consumption for a 75D and why you're not getting anywhere near rated range. This is the problem you need to figure out / solve. You don't have a "degradation" problem, you have a consumption problem.

For reference, my 2016 75 has averaged 315wh/mi over 170,000 miles.

like he said though it really doesnt matter what your consumption is when calculating how much energy you have.. for instance i had a trip of 80 miles into a 50MPH headwind and averaged 470wh/mi but it still calculated out to a capacity of a 76kWh battery

 

[ucmndd]

like he said though it really doesnt matter what your consumption is when calculating how much energy you have.. for instance i had a trip of 80 miles into a 50MPH headwind and averaged 470wh/mi but it still calculated out to a capacity of a 76kWh battery

Too many variables and missing information to draw any real conclusions from OP's analysis.

First, we know the "75" battery isn't really a 75 and only had ~72kwh available for use even when brand new. There has of course been some real degradation of that capacity over 5 years and 60k miles, but certainly not 35% or anywhere near that, as I'm sure the rated range at 100% would show.

We also know the Tesla trip computer is selective at best about what it includes and doesn't include in those figures, and OP hasn't provided any detail about this 65 mile trip that might inform further discussion. Did the car sit at an office all day with Sentry and Cabin Overheat Protection on, which we know uses significant amounts of energy that don't get reported?

OP's next step should be to go into the app and select Service -> Vehicle Range and then run a detailed range analysis on one of these trips for additional info.

And there remains the question as to how OP's wife is averaging 385wh/mi on her trip. That's HIGH.

 

[gt2690b]

Too many variables and missing information to draw any real conclusions from OP's analysis.

First, we know the "75" battery isn't really a 75 and only had ~72kwh available for use even when brand new. There has of course been some real degradation of that capacity over 5 years and 60k miles, but certainly not 35% or anywhere near that, as I'm sure the rated range at 100% would show.

We also know the Tesla trip computer is selective at best about what it includes and doesn't include in those figures, and OP hasn't provided any detail about this 65 mile trip that might inform further discussion. Did the car sit at an office all day with Sentry and Cabin Overheat Protection on, which we know uses significant amounts of energy that don't get reported?

OP's next step should be to go into the app and select Service -> Vehicle Range and then run a detailed range analysis on one of these trips for additional info.

And there remains the question as to how OP's wife is averaging 385wh/mi on her trip. That's HIGH.

this is true he could have some serious vampire drain.. im assuming the figures he's giving are from the trips cards but who knows ...

regarding the high consumption again that shouldnt matter maybe she likes to drive uphill both ways in the snow like my grandparents

 

[ucmndd]

regarding the high consumption again that shouldnt matter

I agree that we're really talking about two separate complaints here, but consumption definitely matters when OP is saying stuff like "ridiculous that with a car that advertises 256 miles you cannot do 130 and we have to charge daily."

 

[jjrandorin]

And there remains the question as to how OP's wife is averaging 385wh/mi on her trip. That's HIGH.

What stood out to me was the OP saying the following:

My wife has 65 miles commute freeway / city with not much traffic so she drives 65 - 75 mph on the freeway

Perhaps its different in NorCal, but on a typical SoCal freeway with "not that much traffic" absolutely NO ONE will be doing "65". Speed would be 70-80, not 65-75, and as any seasoned EV driver knows (but this OP may or may not), consumption does not increase in a linear fashion as speed increases. The OP may think there isnt much difference in going 65 vs 75 (or 80) but there absolutely is, as it relates to battery consumption.

Thats not even talking about elevation changes on the freeway, etc.

I think its likely the OPs spouse was going 75-80 "ish" because thats the likely flow of traffic / speeds that everyone drives, so no one really pays attention to how fast they are going on an open freeway in CA unless there is a law enforcement vehicle around.

 

[ucmndd]

What stood out to me was the OP saying the following:


Perhaps its different in NorCal, but on a typical SoCal freeway with "not that much traffic" absolutely NO ONE will be doing "65". Speed would be 70-80, not 65-75, and as any seasoned EV driver knows (but this OP may or may not), consumption does not increase in a linear fashion as speed increases. The OP may think there isnt much difference in going 65 vs 75 (or 80) but there absolutely is, as it relates to battery consumption.

Thats not even talking about elevation changes on the freeway, etc.

I think its likely the OPs spouse was going 75-80 "ish" because thats the likely flow of traffic / speeds that everyone drives, so no one really pays attention to how fast they are going on an open freeway in CA unless there is a law enforcement vehicle around.

Agree but TBH 385wh/mi isn't explainable even at 80mph without some other external factors like major wind, cold, etc. My lifetime consumption quoted above (315wh/mi) is primarily commuting at CA freeway speeds (for me that means autopilot enabled and set between 78-80 mph).

 

[maximizese]

What stood out to me was the OP saying the following:


Perhaps its different in NorCal, but on a typical SoCal freeway with "not that much traffic" absolutely NO ONE will be doing "65". Speed would be 70-80, not 65-75, and as any seasoned EV driver knows (but this OP may or may not), consumption does not increase in a linear fashion as speed increases. The OP may think there isnt much difference in going 65 vs 75 (or 80) but there absolutely is, as it relates to battery consumption.

Thats not even talking about elevation changes on the freeway, etc.

I think its likely the OPs spouse was going 75-80 "ish" because thats the likely flow of traffic / speeds that everyone drives, so no one really pays attention to how fast they are going on an open freeway in CA unless there is a law enforcement vehicle around.

I gotta disagree here because according to FlatSix911 in this old thread, they would have to be going a sustained 85+MPH which is just not likely. Instead, I would suggest that either there's something wrong in the car's computations or perhaps there is something mechanically wrong like a malfunctioning regenerative system, stuck brake, or something very wrong with the powertrain. What would be best is first enter Service mode to see if there are any alerts, then test the vehicle on a flat and open road to see how much consumption vs speed the vehicle deviates from the chart below. Something is definitely wrong because our old S85 which is inherently less efficient that all the dual motor S's has a lifetime of 311Wh/mi over 126K miles.

Ideal highway speed?

I haven't gone on any long road tips with my MS yet but I'm wondering if there is an ideal speed to travel at. Obviously the faster you travel the more juice you use to overcome wind/road resistance and then end up spending more time superchargeing so you may not make it to your final...

teslamotorsclub.com

 

[2018_TS_S_P75D]

Interesting data and comments, thank you!
My e-golf averages about 350+ Wh / mile, so 385 Wh / mile for Tesla doesn't look outrageous to me.
At 80% full the car reports 180 miles, so 100% is about 225 miles, but this info is useless. Shouldn't the car (as any other car) report the miles left based on fuel left divided by average over the last few (or more) miles consumption? Saying that "the car did 65 miles with 100 miles" is ridiculous.
But, what worries me is the battery health (useable capacity), that has nothing to do with driving style, conditions and potential car defects.
Will follow up with Tesla customer service as the range analysis fails ("Analysis unavailable").

 

[ucmndd]

Shouldn't the car (as any other car) report the miles left based on fuel left divided by average over the last few (or more) miles consumption?

Tesla doesn’t do this. The rated range displayed in the instrument cluster is the calculated available capacity of the battery divided by a constant (not sure exactly what that constant is for a 75D but it’s somewhere near ~300wh/mi for rated range).

225 miles of an original 259 when new is about 13% degradation which is pretty typical for that vintage of 75.

Again: are you using Sentry and/or Cabin Overheat Protection during these trips?

 

[maximizese]

Tesla doesn’t do this. The rated range displayed in the instrument cluster is the calculated available capacity of the battery divided by a constant (not sure exactly what that constant is for a 75D but it’s somewhere near ~300wh/mi for rated range).

225 miles of an original 259 when new is about 13% degradation which is pretty typical for that vintage of 75.

Again: are you using Sentry and/or Cabin Overheat Protection during these trips?

Interesting data and comments, thank you!
My e-golf averages about 350+ Wh / mile, so 385 Wh / mile for Tesla doesn't look outrageous to me.
At 80% full the car reports 180 miles, so 100% is about 225 miles, but this info is useless. Shouldn't the car (as any other car) report the miles left based on fuel left divided by average over the last few (or more) miles consumption? Saying that "the car did 65 miles with 100 miles" is ridiculous.
But, what worries me is the battery health (useable capacity), that has nothing to do with driving style, conditions and potential car defects.
Will follow up with Tesla customer service as the range analysis fails ("Analysis unavailable").

Wow! 350+Wh/mi in an e-Golf? Our 2013 Fiat 500e averages 240Wh/mi which has a Bosch 180/120 motor good for 83kW (puny compared to Tesla). I'm wondering if perhaps your driving habits/region might seriously be an issue. The next thing to check is the Energy app in the MCU; it provides a much more accurate projection of your range based on your set destination (route elevation and possibly traffic taken into account), and also shows projected range based on moving average consumption over your last miles in various intervals. It is waaaaay more accurate than the EPA rated miles shown in the instrument cluster. Please report back with your findings so we can keep trying to help you figure this out.

 

[2018_TS_S_P75D]

I am using the Sentry, but not Cabin Overheat Protection. That is interesting, I read that Sentry mode uses 300W, in 10 hours that is about 3kW. Will look for numbers when the car is parked.
The e-Golf has a 36kwH battery and can do about 100 - 110 miles on the freeway -> 330 - 350 Wh / mile. That is in the book and that is what we see. I am not that familiar with Fiat 500e.
I am checking the Energy app, as the EPA rated miles info is useless.