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

[AlanSubie4Life]

Enjoying my coffee and will be hitting road soon. Have not decided where I want to charge yet between Hesperia or Barstow but will probably be Barstow to 80% and then to Disney parking lot.

I am going the opposite way this morning, in Primm now. Recommend avoiding ALL 150kW chargers like the plague. They are awful.

I would guess your capacity loss is real but it is definitely possible I am wrong because it can have errors.

See below, for this segment of 51kWh, I would expect that to use:
51kWh/234Wh/rmi = 218rmi.

You can see I used 219rmi (293rmi- 74rmi).

Capacity 71.8kWh, usable 68.5kWh, 51kWh is 74%, 219/293 is 75%.

219rmi to go 171mi, near perfect alignment.

You’ll likely see similar. Just have to track it and take these pictures at charge stops.

 

[bkp_duke]

I am going the opposite way this morning, in Primm now. Recommend avoiding ALL 150kW chargers like the plague. They are awful.

I would guess your capacity loss is real but it is definitely possible I am wrong because it can have errors.

Tesla needs to enable in the Nav the ability to exclude all chargers below 250kW. I think right now you can only exclude 72kw and destination.

 

[AAKEE]

I understand there will be car to car variations, but 10% at 12k miles seems a tad . . . excessive.

Not really.

During the (about) five first years, calendar aging cause much higher degradation than the miles driven for the absolute main part of the cars.

This means that the miles driven does not have a big effect of the degradation we see.

The age of the car will set the level (and of course initial capacity, charging habits and climate).

The cart below would probably show a much smaller spread if it had [car age] instead of km/miles on the X axis.

The circle is about at the 10% capacity loss at 12k miles, it is probable that that car has the same age as the cars that is at 50000 to 15000km .

 

[MP3Mike]

How has it been babied ? (I did miss that part earlier in the thread if it was posted.)

I assume they are referring to this:

My max charge has been always to 50% SoC at planned AM departure since week 3 of owning car. 7 Supercharging sessions in life.

I seem to think there has been a pattern of people that try to "baby" their battery by charging to a low SoC are the ones that tend to complain about excessive degradation. That goes back as far as when the Model 3 was originally launched and people charging to 70%, or less, on a regular basis reported horrible degradation, but it was just because the BMS got out of whack because it was designed for charging to 90% on a regular basis. (They had to have Tesla reset their BMS to get reporting to be more accurate, starting to charge to 90% didn't correct the problem in a reasonable time frame.) I think Tesla has made changes so that it estimates better now even when charged to a low SoC, but that could be part of your problem.

FYI: If you look at Rivian they only give you three SoC to pick from to charge to: 70%, 85%, and 100%. You can't pick any other percent to charge to. So maybe the chemistry currently used by EVs doesn't behave the same way as all the older studies show Lion batteries behave.

 

[AlanSubie4Life]

I seem to think there has been a pattern of people that try to "baby" their battery by charging to a low SoC are the ones that tend to complain about excessive degradation

Since I started using 50-60% as a limit (rather than consistent 80%-90%) my range has increased from 286 (a pretty consistent one too), to 293. So YMMLV (L = literally).

It’s all just noise. And estimation algorithm changes.

Only 8% loss (293/318 (310) ) after four years, not bad. Seems like capacity is really there after metering it closely too.

 

[KenC]

I assume they are referring to this:



I seem to think there has been a pattern of people that try to "baby" their battery by charging to a low SoC are the ones that tend to complain about excessive degradation. That goes back as far as when the Model 3 was originally launched and people charging to 70%, or less, on a regular basis reported horrible degradation, but it was just because the BMS got out of whack because it was designed for charging to 90% on a regular basis. (They had to have Tesla reset their BMS to get reporting to be more accurate, starting to charge to 90% didn't correct the problem in a reasonable time frame.) I think Tesla has made changes so that it estimates better now even when charged to a low SoC, but that could be part of your problem.

FYI: If you look at Rivian they only give you three SoC to pick from to charge to: 70%, 85%, and 100%. You can't pick any other percent to charge to. So maybe the chemistry currently used by EVs doesn't behave the same way as all the older studies show Lion batteries behave.

There's no clear rhyme or reason to me.

I'm one of those people that charges to 60%, for the last 3+yrs; higher if necessary on roadtrips. SMT reports I have 76.4kWh still, which is in the top buffer, so the car is going to show no deg. Even at my low SOC levels, my car shows cell imbalance to be 6mV, which seems fairly normal to me.

If my car were in Teslalogger.de, it'd be the red circle:

 

[Bouba]

Hi everyone...just downloading 2022.28.2....I noticed that on NotaTeslaApp they say there is an undocumented feature

For the 3 and Y...and it says it will calibrate the battery....does anyone know if this will give a more accurate reading?

 

[CyberGus]

Hi everyone...just downloading 2022.28.2....I noticed that on NotaTeslaApp they say there is an undocumented feature
View attachment 857329

For the 3 and Y...and it says it will calibrate the battery....does anyone know if this will give a more accurate reading?

It's probably phantom calibrating

 

[Bouba]

So..I did an experiment…I put a couple of extra percentage points of charge in…and nothing…just like always..it goes from ‘charging’ to ‘charging complete’ with no step in between

 

[MP3Mike]

So..I did an experiment…I put a couple of extra percentage points of charge in…and nothing…just like always..it goes from ‘charging’ to ‘charging complete’ with no step in between

I don't think the "calibrating" comes up until you hit 100%. (Or maybe it starts towards the end of 99%, I don't recall.)

 

[Bouba]

If Teslas can accurately self calibrate...then half the posts on this forum would stop...

 

[DownshiftDre]

By babied, I mean I always setup scheduled departure charge to charge up to 50% right before departure at around 8am since I had the car in April 2022. 4 road trips from Vegas to CA with associated supercharging. 90-100% SoC when leaving house for those.

On the trip to Disney few days back, charging to 100% before leaving home only got 271miles. Lined up with where I thought since 50% was at 135miles and rough math gave the same close 270 expected for 100%.

Unfortunately the pics I took were not of the trip meter page but the energy chart page. Misunderstanding on my part.

I also did not end up going to Hesperia because my daughter needed to go to restroom so I ended up charging at Yermo (Eddies) instead. I have a 5 and 3 year old so pitstops are necessity whether gas or electric. With electric those pitstops turn into opportunities lol.

I will say new calcs from battery indicator miles and SoC show that something has recalibrated in thr direction of goodness. Math for 100% says I will be at 278 now. Dont plan to go to 100% again until maybe cooler temps and road trip. That puts it at 8.2% degradation instead of 12%. Will try again next road trip.

 

[AAKEE]

By babied, I mean I always setup scheduled departure charge to charge up to 50% right before departure at around 8am since I had the car in April 2022.

The car was new in April?

The degradation shouldn’t be that high even in extreme high temperatures.
50C at 50% for about 5 months should cost about 5% calendar aging. The cyclic aging including Supercharging should be very low.

Do you know your cars initial range at 100%?

 

[DownshiftDre]

The car was new in April?

The degradation shouldn’t be that high even in extreme high temperatures.
50C at 50% for about 5 months should cost about 5% calendar aging. The cyclic aging including Supercharging should be very low.

Do you know your cars initial range at 100%?

Want a real fun stumper?

How about we stop talking about my wifes 2022 MYP and start talking about my garage queen 2022 M3P born June 2022?

I know range on my M3P showed 315 at new when I fully charged it first week I got it June 9th. Now has 1100 miles. Super babied battery where sometimes it will sit at 30% or less for days in garage. Extrapolated range from battery icon calculation on my M3P now says 100% would extrapolate to 288miles.

Yes Vegas is hot for 3.5 months of the year but there is no way I have 10% degradation on a garage queen M3P. Calibration algorithm is truly deficient when charging only to 50%.

So what is the better charging method for actual useable range? 1) higher level charging and having a more accurate calibration or 2)charging to lower levels but having a messed up calibration that could be leaving range off the table? Seems best range is a combination of both low level charging with frequent calibration friendly charges.

 

[AlanSubie4Life]

By babied, I mean I always setup scheduled departure charge to charge up to 50% right before departure at around 8am since I had the car in April 2022. 4 road trips from Vegas to CA with associated supercharging. 90-100% SoC when leaving house for those.

On the trip to Disney few days back, charging to 100% before leaving home only got 271miles. Lined up with where I thought since 50% was at 135miles and rough math gave the same close 270 expected for 100%.

Unfortunately the pics I took were not of the trip meter page but the energy chart page. Misunderstanding on my part.

I also did not end up going to Hesperia because my daughter needed to go to restroom so I ended up charging at Yermo (Eddies) instead. I have a 5 and 3 year old so pitstops are necessity whether gas or electric. With electric those pitstops turn into opportunities lol.

I will say new calcs from battery indicator miles and SoC show that something has recalibrated in thr direction of goodness. Math for 100% says I will be at 278 now. Dont plan to go to 100% again until maybe cooler temps and road trip. That puts it at 8.2% degradation instead of 12%. Will try again next road trip.

You are the only one who can answer the degradation question and whether it is real. You have access to the best estimate in the world of your car’s capacity. My car seems accurate within a percent or so.

Mostly downhill run (6300 feet), so a lot of regen. No stopping at all.

291rmi at 100%, so that is 71.3kWh, 68.1kWh usable. (245Wh/rmi, 234Wh/displayed rmi for my car - your Model Y and 3 are different,but trivial to determine - for a degraded car, just charge to 100%, take ProjRang*RecentEfficiency/(rmi@100%) - does not work for a new car though.)

263mi at 225Wh/mi, 59.2kWh, left me at 35rmi after starting at 291rmi.

So that’s (291rmi-35rmi)*234Wh/rmi = 59.9kWh.

So within about 1%. Obviously could be rounding errors which could contribute to that error.

So anyway just do the same, end of story really. No one here can tell you - but you can definitely determine what is happening with your vehicle.

Beefalo! (Not bison.)

I’d be surprised if your car was more than 3 percent off on its estimate on such a test.

 

[Candleflame]

I assume they are referring to this:



I seem to think there has been a pattern of people that try to "baby" their battery by charging to a low SoC are the ones that tend to complain about excessive degradation. That goes back as far as when the Model 3 was originally launched and people charging to 70%, or less, on a regular basis reported horrible degradation, but it was just because the BMS got out of whack because it was designed for charging to 90% on a regular basis. (They had to have Tesla reset their BMS to get reporting to be more accurate, starting to charge to 90% didn't correct the problem in a reasonable time frame.) I think Tesla has made changes so that it estimates better now even when charged to a low SoC, but that could be part of your problem.

FYI: If you look at Rivian they only give you three SoC to pick from to charge to: 70%, 85%, and 100%. You can't pick any other percent to charge to. So maybe the chemistry currently used by EVs doesn't behave the same way as all the older studies show Lion batteries behave.

the algorithm has been updated and this is not an issue anymore.

 

[DownshiftDre]

the algorithm has been updated and this is not an issue anymore.

See my issue few posts up with my 1500 mile M3P few months old that shows a perceived erroneous 10% degradation. Seems there is some miscalibration that occurs with low SoC charging.

 

[AlanSubie4Life]

See my issue few posts up with my 1500 mile M3P few months old that shows a perceived erroneous 10% degradation. Seems there is some miscalibration that occurs with low SoC charging.

It may well be real. Only you can determine that though. See above.

It’s about 256Wh/rmi for that vehicle for your calculations after you do a long drive. (Can confirm with method above.)

Obviously can only find out with a longer drive, but that is also the only time this matters at all.

10% is definitely high for that vehicle age so an error in the estimate seems possible. We’ve seen such errors recover over the course of weeks. But if yours has been steady and doesn’t change after a charge to 100% I would believe it.

 

[AlanSubie4Life]

that shows a perceived erroneous 10% degradation. Seems there is some miscalibration that occurs with low SoC charging.

But if yours has been steady and doesn’t change after a charge to 100% I would believe it.

When I say “I would believe it” I mean I would not count on there being more. This does not mean that I think the estimate is correct. The only way to determine that is to drain the vehicle on a drive. I have NEVER seen a more than ~1% mismatch on available energy vs. the estimate, and I have checked many times (typically I find that actual available energy is about 1% less than the estimate on my vehicle, as seen above).

I should have tried to make it to Primm, and drafted a bit more! Could have got down to 0% and really verified it! Definitely could have driven 300 miles, with care, on that run. I was driving up to 85mph with minimal lead traffic (most were going faster) after hitting I-15; not optimal for extending to Primm. But anyway I think an 88% extrapolation is just fine, and of course practically speaking it is all that matters.

 

[DownshiftDre]

When I say “I would believe it” I mean I would not count on there being more. This does not mean that I think the estimate is correct. The only way to determine that is to drain the vehicle on a drive. I have NEVER seen a more than ~1% mismatch on available energy vs. the estimate, and I have checked many times (typically I find that actual available energy is about 1% less than the estimate on my vehicle, as seen above).

I should have tried to make it to Primm, and drafted a bit more! Could have got down to 0% and really verified it! Definitely could have driven 300 miles, with care, on that run. I was driving up to 85mph with minimal lead traffic (most were going faster) after hitting I-15; not optimal for extending to Primm. But anyway I think an 88% extrapolation is just fine, and of course practically speaking it is all that matters.

Do you live somewhere in CA or NV? Not sure where that beefalo is lol. You look well aware of all the I-15 stops.

But yes definitely point taken. Looks like best method is next road trip to CA will measure kwh consumed from home to farthest destination I can get (assuming no prematyre potty breaks in the way). Will definitely be performed with my wifes MYP and not my garage queen M3P. Its the M3P “degradation” that bothers me most actually considering its so new.