Range on midrange reduced to 219 miles

[AlanSubie4Life]

Lmao...thanks for the info but this is the exact thing many of us gripe about. I shouldn't have t be a battery chemist just to be able to determine if Tesla sold me a car with a defective battery. As an end user, essential information on such a highly sophisticated vehicle should be easy to comprehend and digest.

As I said, you don't have to do this. Has nothing to do with being a battery chemist.

If your rated range is low at 100%, that means you have less energy as compared to someone else with the same car showing more miles (and it is exactly linearly proportional). I'm just providing the means above to prove that that is the case (so you don't have to take my word for it). Or you can take my word for it.

You just see a lot of stuff on this site about this being an "estimate" and that you can "recover" this number, and it may not reflect your actual battery health, and it's simply not true. To within 1% (+/-3 miles), this number is very precise, and pretty much nothing affects it other than loss of capacity and fairly cold temperatures (say below 50-60 degrees F).

If your number is low, one or more of your bricks has limited capacity. Very simple. Who cares why or what precisely is "wrong" with the battery - there may be nothing wrong other than age - from a practical standpoint, it means you have less range.

 

[duanra]

Model 3 Mid Range
Built: Feb. 2019
80% charge = 197 miles indicated range
90% charge = 217 miles indicated range
100% charge = 242 miles (shown on app slider)

If you go by the slider, the battery temperature could make a big difference. By -10c with no preheat first thing in the morning before driving, it could show as low as 96% or the equivalent mileage.

 

[TimothyHW3]

100% charge = 242 miles (shown on app slider)

As for the app slider - wait for warmer weather and charge to 100%. The estimate can play a lot of games if the outside temperature is below 10C 50F.

 

[Toppatop55]

As I said, you don't have to do this. Has nothing to do with being a battery chemist.

If your rated range is low at 100%, that means you have less energy as compared to someone else with the same car showing more miles (and it is exactly linearly proportional). I'm just providing the means above to prove that that is the case (so you don't have to take my word for it). Or you can take my word for it.

You just see a lot of stuff on this site about this being an "estimate" and that you can "recover" this number, and it may not reflect your actual battery health, and it's simply not true. To within 1% (+/-3 miles), this number is very precise, and pretty much nothing affects it other than loss of capacity and fairly cold temperatures (say below 50-60 degrees F).

If your number is low, one or more of your bricks has limited capacity. Very simple. Who cares why or what precisely is "wrong" with the battery - there may be nothing wrong other than age - from a practical standpoint, it means you have less range.

So, I used the Tesla remote app the other day and charged from 2% and 6 miles on the to 100% 286 miles (first time ever doing so I attempt to reset the BMS). The app indicated that I added 68.73 kWh and 280 miles.

 

[TimothyHW3]

I hate to contradict Alan again to get into discussions... but the added kWh are misleading. While the car is on it consumes 300W so for every 1 hour you get 300Wh used. The only way to see how big your battery is without Scan My Tesla is to drive it from 100-0% on one turn and see how much kWh were USED! This will give you the number. But the 100% range shown inside the car gives you also a good indication wether there is some missing range, for whatever reason (BMS uncalibration or real degradation)...

 

[AlanSubie4Life]

I hate to contradict Alan again to get into discussions... but the added kWh are misleading. While the car is on it consumes 300W so for every 1 hour you get 300Wh used. The only way to see how big your battery is without Scan My Tesla is to drive it from 100-0% on one turn and see how much kWh were USED! This will give you the number. But the 100% range shown inside the car gives you also a good indication wether there is some missing range, for whatever reason (BMS uncalibration or real degradation)...

Nope. That overhead is included in the charging efficiency of 89% - I mentioned that in my original post! The efficiency at warm conditions with a 7.7kW charge rate is quite a well controlled number, and is published by Tesla. And of course their number must include overhead otherwise they would be breaking the law.

In addition, a comparative test to an equivalent vehicle using an equivalent charging setup and charge rate makes this a completely valid way to check capacity between two vehicles. It's awesome, and easy.

We've already done it with an SR; the results were exactly as expected (I think it was within 1% as I recall).

You can also drive from 100% to 0% on one drive as well, of course, that is equally valid (and will give you a result that is about 2% lower than what SMT and the charging method tells you).

 

[AlanSubie4Life]

So, I used the Tesla remote app the other day and charged from 2% and 6 miles on the to 100% 286 miles (first time ever doing so I attempt to reset the BMS). The app indicated that I added 68.73 kWh and 280 miles.

View attachment 520743

No, you can't do that. That's just giving you the 245Wh/rmi charging constant (which is wrong, by the way - it's just what the car reports in the API but doesn't reflect the actual energy added!). Also doesn't include any charging overhead or any AC-DC conversion losses.

Just use the wall energy data and you'll be fine. You can't use any data from any app (other than ScanMyTesla of course).

If you gather the extremely precise data as described I can parse it for you. It's all totally trivial calculations though.

You can also use SMT or check the trip meter for a single continuous discharge without stopping from 100% (or 90%, doesn't really matter) to 0%. The trip meter has a way of missing used energy which is why I don't prefer it, but it is perfectly valid when used correctly (though it does lose about 2% of the energy anyway).

All this stuff is super systematic and basically completely repeatable. There's no mystery to it at all really. Kudos to Tesla for making it very straightforward - no guesswork needed - extremely easy to see how much loss of capacity you have (with a couple of small caveats I have described elsewhere).

 

[Toppatop55]

Alan you lost me at "overhead." lmao.....I'm sure you are perfectly correct in your explanation, but 99.9% of have no idea of all the technical jargon. I consider myself a well educated man but I don't want to do any trigonometry to know if I'm getting what I was promised before purchase. I just want to charge my car to 100% and see the milage I paid for or at least something very close this early on in the ownership time.

 

[AlanSubie4Life]

Alan you lost me at "overhead." lmao.....I'm sure you are perfectly correct in your explanation, but 99.9% of have no idea of all the technical jargon. I consider myself a well educated man but I don't want to do any trigonometry to know if I'm getting what I was promised before purchase. I just want to charge my car to 100% and see the milage I paid for or at least something very close this early on in the ownership time.

You just need to know multiplication then. Charge your car to 100%.

Multiply that number by 245Wh/rmi. That's your capacity in Wh (divide by 1000 to give you your capacity in kWh).

Very simple.

Note you cannot use this formula for any rated miles value other than the rated miles at 100%. (In other words, if you multiply your rated miles at 90% by 245Wh/rmi, that will give you the wrong answer for your remaining energy - it'll be a slightly pessimistic answer.)

 

[Toppatop55]

You just need to know multiplication then. Charge your car to 100%.

Multiply that number by 245Wh/rmi. That's your capacity in Wh (divide by 1000 to give you your capacity in kWh).

Very simple.

Note you cannot use this formula for any rated miles value other than the rated miles at 100%. (In other words, if you multiply your rated miles at 90% by 245Wh/rmi, that will give you the wrong answer for your remaining energy - it'll be a slightly pessimistic answer.)

I just did the math as you stated and my capacity comes out to be 70.07 kWh. I'm assuming the other 5kWh is the underhand over buffer

 

[AlanSubie4Life]

I just did the math as you stated and my capacity comes out to be 70.07 kWh. I'm assuming the other 5kWh is the underhand over buffer

That number INCLUDES the buffer (which is 4.5% of your full charge).

So you have 70.07kWh*0.955 = 66.9kWh available from 100% to 0%.

It's all super simple. And you'll be able to see about 65.6kWh on the trip meter for that discharge (since about 2% of the energy goes missing when referenced to the trip meter).

There's a tiny amount of slop on these numbers, but when we're talking about a reduction of 8kWh from when the car was new, a 0.5kWh error here and there does not matter much.

Anyway, your result is definitely on the low side, but relatively common.

 

[Toppatop55]

That number INCLUDES the buffer (which is 4.5% of your full charge).

So you have 70.07kWh*0.955 = 66.9kWh available from 100% to 0%.

It's all super simple. And you'll be able to see about 65.6kWh on the trip meter for that discharge (since about 2% of the energy goes missing when referenced to the trip meter).

There's a tiny amount of slop on these numbers, but when we're talking about a reduction of 8kWh from when the car was new, a 0.5kWh error here and there does not matter much.

Anyway, your result is definitely on the low side, but relatively common.

So is that acceptable on a car that's 8 months old with 6k miles. in fact the drop in range started right after that controversial update in the fall when the car was only a couple months old. AND is it me or is it suspect that everyone who is experiencing this issue seems to be loosing the same exact percentage and mileage. That cannot be "normal" random degradation.

 

[theRed]

As for the app slider - wait for warmer weather and charge to 100%. The estimate can play a lot of games if the outside temperature is below 10C 50F.

That data is from today, it is 68 degF in San Diego, so I don't think it is temperature related. I'm mostly just curious if others are seeing numbers close to mine or if it is something I should contact Tesla Service about. Seems its mostly normal.
What was concerning for me was for the first 6 months of ownership my 100% range was ~260-262 miles, then it seemed to drop overnight to 250 and now it is somewhere around 242.

 

[TimothyHW3]

Nope. That overhead is included in the charging efficiency of 89% .

Yes, 10-12% could be in the ball park but as I tested here it can go over to 17% depending on the charger speed and how long you will take.

Without going into any discussions, the best way is to drive to 0% and see what used kWh shows, that is the most correct way. Everything else is guesstimation.

Alan you lost me at "overhead."
I just want to charge my car to 100% and see the milage I paid for or at least something very close this early on in the ownership time.

The overhead he is talking about is called "heat loss". It is the amount that is lost between your wall and the car (in the cables, in the inverters etc.) It could be as low as around 5% on a Tesla Supercharger or about 10-15% depending on your home kW charger.
Also, while the car is charging it is still on and consumes energy so this is also "overhead".
At a Tesla supercharger - if you sit inside the car, have HVAC on play games, it will be even more.

Basically if you see 200Wh/m, you have to add that overhead to understand what the real consumption is. Because even though the car consumed 200Wh/m, to get back those 200Wh into the battery, you have to add 220Wh/m. It is like sipping watter into a bucket and spilling over...Overhead.

Also there is energy being "lost" while charging to heat up the battery with the motors if the weather is cold (not sure where you live) Also "overhead".


As for the 100% charge - you can still do that. If the battery is warm it will yield the correct capacity according to the BMS.
I would change into km - so basically the math for the capacity is:
Whatever the value at straight line under energy graph - multiply it by the miles and this will get you capacity.
On LR AWD in km it is:
153Wh/km * 500km = 76.5kWh when brand new (this is including a 3.5kWh buffer below 0%)

You can do the math in miles, but I would change to km as it is more accurate.

Having 70kWh on a basically brand new car at 8 months is not "normal", but it could be just BMS issue as most people suffer from - due to your topping up only the 70%-90%

I am at about 75kWh at 9 months and 15 000 miles and I have seen people at 30000 miles and 12 months at 76kWh, almost brand new.

 

[AlanSubie4Life]

Yes, 10-12% could be in the ball park but as I tested here it can go over to 17% depending on the charger speed and how long you will take.

Yes, that is why you use a formula and the charge power to calculate the efficiency. You really just need one point and the rest of the data fits very well. You can see it in your video.

The point is we have the single datapoint from Tesla that tells us the efficiency very precisely at a 7.7kW charge rate.

And as I originally said, the battery must be warm for any such test so there is no additional overhead. Your video had some snowflakes at points which makes it less useful for this experiment.

 

[TimothyHW3]

If you actually watch the video I explained that I warmed the battery before the snowflake and only started recording when the battery warmed up. The battery was still not optimal above 20 but was at nice 15C or so and remained that way through the night.

 

[smashcz]

I just want to charge my car to 100% and see the milage I paid for or at least something very close

Agree