2020, 2019, 2018 Model 3 Battery Capacities & Charging Constants

[Candleflame]

It is exactly related to the capacity and constant.

Full capacity/Tesla constant= displayed range at 100%, this is a beaten to death topic.

However on the 2018/RWD and 2019 AWD models Tesla willingly used a part of the capacity to display range(76.5/5 on 2019)- then they started using the full 77.8 hence the 318miles range over similar constant.

Also, a few people have tested 2021 vs 2019 driving same speed with heater off and it seems there is no measurable difference in motor efficiency

the issue is that we dont know what capacity tesla used. capacity isnt static and different cars might be delivered with different max kwh. Which is why some cars get delivered i.e. with 312miles rated range rather than 310. I.e. my car came with 502km rather than 499 km.

The BMS assigns each watthour a fixed km constant (which when made up to 1km equals one rated km) which is difficult to figure out and while total kwh / total displayed km might get you close it may not actually be reflective of what this value is.

On the basis that 1 rated km = 0.149wh we could presume that the 77.8kwh battery capacity for a 2019 Model 3 awd is therefore VERY reflective of the 499km capacity (77.8 x 0.955 / 0.149 = 499km). But we cant know for sure that 1 rated km is actually 0.149. It could also be 0.148 or 0.150 or maybe 0.151. We are all just speculating. We know that the internal kwh consumed isnt particularly accurate anyway - and noone really knows why.

 

[AlanSubie4Life]

The BMS assigns each watthour a fixed km constant (which when made up to 1km equals one rated km) which is difficult to figure out and while total kwh / total displayed km might get you close it may not actually be reflective of what this value is.

But we cant know for sure that 1 rated km is actually 0.149. It could also be 0.148 or 0.150 or maybe 0.151.

I can't be 100% sure on a vehicle that is above the degradation threshold for capacity loss, but after a vehicle is degraded, you can always tell (to the closest Wh/km) what the constant is, directly from the Energy Consumption graph (not using the rated line or paying any attention to any lines).

See above for the math. It's really simple and convenient and it always tells you the value of the constant. As I said, not sure what happens when you have more energy than the degradation threshold. As a specific example, take a brand new 2018 Model 3 AWD showing 310 rated miles at 100%, with 77.5kWh of capacity per the BMS (from SMT):

The constant is 245Wh/mi (we know this, for certain).

77.5kWh/310rmi = 250Wh/mi.

So, the question is, if you look at the consumption screen and do the above calc, do you come up with the answer 245Wh/mi, or is the extra capacity accounted for on the consumption screen and you come up with 250Wh/mi? I have no idea, since that state of no degradation does not last for long and I cannot check it. (I suspect the answer will still be 245Wh/mi for a 2018 AWD in this case, but I don't know.)

However, putting that unknown aside, taking the example that is known, take that same 2018 Model 3 AWD degraded to 307rmi:

Use the energy consumption screen, and you'll be able to calculate from the Projected Range, Rated Miles Remaining, %, and Recent efficiency, your full battery capacity:

Projected Range*Recent Efficiency / Rated Miles Remaining * (Rated Miles Remaining/%) = Full capacity

Or more simply Projected Range * Recent Efficiency / % = Full capacity (obviously some rounding error, two significant digits only in the result, so only accurate to the nearest kWh unless you work to determine the rounding error).

So for example, say you're at 80%, recent efficiency is 280Wh/mi, projected range is 215 miles:

280Wh/mi*215mi / 0.8 = 75kWh

You can try this on your car if any doubt and compare to SMT.

Which is why some cars get delivered i.e. with 312miles rated range rather than 310.

That would be interesting. I've never seen a picture of a 2018 AWD exceeding 310 rated miles, nor have I seen a picture of a 2020 AWD exceeding 322 rated miles. When actually charged to 100% (not projected by the app from 80% or 90%, of course, which is not meaningful since there is error on the projection). I believe any excess energy is hidden, as discussed elsewhere, by making rated miles/km more energetic.

I will do my own tests once I have the car.

Are you replacing your old vehicle?

display range(76.5/5 on 2019)- then they started using the full 77.8 hence the 318miles range over similar constant.

I am not sure whether rated range max in km was 500 or 499 for 2018/2019 AWD. I will assume 499 here.

Specifically, they went from Model 3AWD 2018/2019: 76kWh/499rkm = 152Wh/rkm to Model 3 AWD 2020: 77.6kWh/518rkm = 150Wh/rkm.

(It's possible it is 77.8kWh rather than 77.6kWh, but I think the data I have seen points to 77.6kWh. Small and insignificant discrepancy in any case.)

 

[TimothyHW3]

502km rather than 499 km.

Did you actually charge to 100% and it showed 502km inside the car? No, it was either projected by the Tesla App(which is flawed) or by some 3rd party app calculation based on rounding error. The max displayed inside the car is 499km or 500km, only RWD had 525km...

This topic has been beaten to death, use the search inside the forum

 

[TimothyHW3]

will assume 499

I think it was 499km too, but I think it could've been 500 on some cars(mine never really charged to 100% always 99% or close to 100%). I think the highest I got was 498 or maybe 499km, but def not 502, that is just an error in the Tesla App not calculating properly when you move the slider

But that is besides the point - the point is that Tesla is playing a dangerous game here. I am yet to see if there is such huge improvement in the motors to explain 50miles of difference. Even the heat pump in ideal conditions and poorly setup 2019 car wouldn't bring that much difference. Interesting to see what the US cars will show @100% and wether it will be above 332 miles

 

[AlanSubie4Life]

But that is besides the point - the point is that Tesla is playing a dangerous game here.

It's not really a dangerous game; it's the game they have been playing for some time. It's fine. These new cars really will get better range in inclement weather (it even seems to do better in hot weather...check out the SC03 results for the SR and compare to 2019 version...) and there is something to be said for that. Fundamentally (see my separate thread on the 2021 testing data) they aren't much more efficient than 2020 - it does appear the rear motor on the 2021 AWD may be the 2020 Performance motor (someone should check the plate ASAP!!!! I will give a generous reward to the first person with a photo. The reward is a thank you from me!), the rolling resistance was specified slightly lower than 2019, and the rest is heat pump.

If you want to understand it, read:

The Adjustment Factor Tesla Uses to Get Its Big EPA Range Numbers

. I am yet to see if there is such huge improvement in the motors to explain 50miles of difference. Even the heat pump in ideal conditions and poorly setup 2019 car wouldn't bring that much difference.

Again, this has been covered in that other thread ( Preliminary EPA Data for Model 3 AWD & Model 3 P 2021 Released ), but this is the summary:

So the pareto, AWD, adding 31 rated miles, to go from 322 to 353:
1) 18 miles improvement due to scalar changes (heat pump); will not be "realizable" if not using climate control.
2) 13 miles improvement due to efficiency improvements (apparently taking on the Performance 2020 rear motor?)

Hypothetical Performance Pareto, adding 16 rated miles:
1) 8 rated miles added due to capacity increases. (Assuming they stick.)
2) 8 rated miles added due to heat pump (not realizable if not using climate control)

Interesting to see what the US cars will show @100% and wether it will be above 332 miles

They'll show about 353 rated miles. No question about that. It's still "estimated" on the webpage so it might go up slightly but the initial test that Tesla did showed 353 rated miles.

 

[AlanSubie4Life]

It's still "estimated" on the webpage so it might go up slightly but the initial test that Tesla did showed 353 rated miles.

I take this back. This is the "final" number which shows when the number has been finalized. It might still go up later, but would require a new EPA document to show up. We'll see 353 rated miles on the vehicles delivered in the United States shortly.

 

[Candleflame]

Did you actually charge to 100% and it showed 502km inside the car? No, it was either projected by the Tesla App(which is flawed) or by some 3rd party app calculation based on rounding error. The max displayed inside the car is 499km or 500km, only RWD had 525km...

This topic has been beaten to death, use the search inside the forum

charged to 100% showing 502km. This is normal as the BMS notices a slightly larger battery - this happens when you luck out and have a car with slightly higher capacity (which does vary a little bit). The car used to charge to like 453km or so at 90% as well. It did drop quickly though over the first 2000.

 

[AlanSubie4Life]

charged to 100% showing 502km. This is normal as the BMS notices a slightly larger battery - this happens when you luck out and have a car with slightly higher capacity (which does vary a little bit). The car used to charge to like 453km or so at 90% as well. It did drop quickly though over the first 2000.

Interesting. Any pictures of that range (as displayed in the car or in the Tesla app)? This is a 2018/2019 AWD right? As I said, I've literally never seen a picture showing in excess of 310 rated miles for pre-2020 AWD.

 

[Candleflame]

Interesting. Any pictures of that range (as displayed in the car or in the Tesla app)? This is a 2018/2019 AWD right? As I said, I've literally never seen a picture showing in excess of 310 rated miles for pre-2020 AWD.

no picture. this is a 2019 performance. After like 600km mine dropped to like 498km though at 100%.

 

[TimothyHW3]

charged to 100% showing 502km

On a 2019 AWD or P, not RWD? 502 on the car display? Sorry, I don't believe it, you would be the first, happen to have a pic of that?

Edit: no picture and extrapolated from 90%. Exactly as predicted...

 

[Candleflame]

On a 2019 AWD or P, not RWD? 502 on the car display? Sorry, I don't believe it, you would be the first, happen to have a pic of that?

Edit: no picture and extrapolated from 90%. Exactly as predicted...

if you want to believe you go to church or whatever you say in Germany.

it was 502km at 100% on a 2019 Stealth performance.

 

[AlanSubie4Life]

if you want to believe you go to church or whatever you say in Germany.

it was 502km at 100% on a 2019 Stealth performance.

The only reason I doubt this report (and I have to label it as "unconfirmed" without a picture) is that there are examples of 2018/2019 AWD/Performance vehicles with more than 76kWh (more like 77.5kWh according to SMT) showing just 310 rated miles (or 499rkm) at a full charge. That doesn't pencil out to the right constant. So: both that observation and your observation seem like they can't both be true unless there was a brief software difference, etc. underlying the different behavior. In fact, I think @TimothyHW3 has captures from his vehicle with SMT showing 77+kWh. Unfortunately I'm not sure he has contemporaneous pictures of (preferably in the same shot) showing his vehicle with just 499rkm at 100% in that situation.

One way to try to reconfirm this now is to have people with brand new vehicles get SMT right away and carefully track their rated miles at true 100% AND the readbacks from SMT over time. But now the time period where no degradation shows may well be shorter (since max is now (2020) 77.6kWh (might be something different for 2021, we don't know yet) rather than 76kWh (2018/2019)). So harder to see what happens in this period. Especially since people don't charge to 100% too often.

Another way: confirmatory evidence for your observation would also be someone showing a picture of a 2021 displaying more than 353 rated miles (assuming that is the rating that sticks). But of course Tesla could change the way they treat this at some point, so it's hard to use that as confirmation, too. But it would be supportive of your observation in any case.

 

[TimothyHW3]

One way to try to reconfirm this now is to have people

There is no way to confirm it, it only shows 500km. I know this because I have seen many reports of people claiming that, and when you press them a little to give you pictures etc, they admit it was from the app by pulling the toggle to 100% - the usual explanation is - if the app says that then I am sure the car will show the same etc. Sure... He just half-heartedly admitted it above, when he said it was extrapolated from 90%...

 

[AlanSubie4Life]

He just half-heartedly admitted it above, when he said it was extrapolated from 90%...

He didn't though.... (He did clarify as well as he could that this was not a projected number...)

charged to 100% showing 502km.

it was 502km at 100% on a 2019 Stealth performance

I'm open to the possibility that there could have temporarily been a version of the software that would have shown greater than 499km/500km (310 rated miles). All it would require is a small programming mistake and then any excess capacity would be revealed in this fashion.

 

[TimothyHW3]

All it would require is a small programming mistake

Yes, there is - in the app

 

[AlanSubie4Life]

Yes, there is - in the app

Not sure what you're referring to with this. Obviously there is extrapolation error (due to rounding error) in the app when you project to 100%. That's not a programming error, it's just the limitation of the API (which for some reason doesn't provide fractional % and fraction rated miles, or at least doesn't use that info).

I'm talking about a true 100% charge showing more than 499km. I've never seen it, but I'm not going to rule out the possibility that at some point in the past there could have been a temporary programming issue which resulted in Remaining Rated km = Battery Energy / Constant being displayed, when Battery Energy > Energy Degradation Threshold. They would just have to screw up a conditional statement in the code.

That being said, I would have expected more reports at the time - but they have in the past quickly pulled back software updates so it could have been a very limited release, and very temporary.

This is all hypothetical. I'm taking observations at face value and trying to fit them to the facts that we're aware of (specifically: that vehicles currently never show over the max rated miles, even if they have more energy than that).

 

[Candleflame]

Not sure what you're referring to with this. Obviously there is extrapolation error (due to rounding error) in the app when you project to 100%. That's not a programming error, it's just the limitation of the API (which for some reason doesn't provide fractional % and fraction rated miles, or at least doesn't use that info).

I'm talking about a true 100% charge showing more than 499km. I've never seen it, but I'm not going to rule out the possibility that at some point in the past there could have been a temporary programming issue which resulted in Remaining Rated km = Battery Energy / Constant being displayed, when Battery Energy > Energy Degradation Threshold. They would just have to screw up a conditional statement in the code.

That being said, I would have expected more reports at the time - but they have in the past quickly pulled back software updates so it could have been a very limited release, and very temporary.

This is all hypothetical. I'm taking observations at face value and trying to fit them to the facts that we're aware of (specifically: that vehicles currently never show over the max rated miles, even if they have more energy than that).

its get over 45 degrees here and the car routinely moves from i.e. 70% charge to 73% charge after charging. so its also not implauseable that i managed to charge to 100.3%.

 

[TimothyHW3]

managed to charge to 100.3%.

You can charge to 170.3%, the car will still show 499/500km - on display. It is capped, as previously stated, to hide initial degradation above 76.5kWh. Just admit it was the tesla app or/and extrapolated value from 90% or a third party app showing that and we can move on...

 

[Candleflame]

You can charge to 170.3%, the car will still show 499/500km - on display. It is capped, as previously stated, to hide initial degradation above 76.5kWh. Just admit it was the tesla app or/and extrapolated value from 90% or a third party app showing that and we can move on...

well now i wish i would have taken a picture to show you

 

[TimothyHW3]

We have a Canadian? SR+ with about 135Wh/km.

What was the SR+ before, haven't followed it? It seems the battery is slightly bigger, previously 52.5 now 53.5 when new, 1kWh or thereabouts.