I think my car is lying to me...

[supratachophobia]

But the problem is, the EPA test determines what the rated range is, which is actual miles driven on a full charge, and that doesn't include the buffer.

I've heard rumors that the EPA test drives until the car won't go any further. What that means for the actual battery, is the point where the modules can no longer provide enough combined power to propel the car forward. Some have tried to drive beyond 0% to varying degrees of success. My guess is that for EPA testing, Tesla allowed them to use the 4kwh brick protection and take the battery to nominal charge = 0 to get their EPA rating. But in practice, they make 4kwh nominal 0% so that drivers don't dip into it. And dip into it at their own risk because you could have a module imbalance that the car would shut off at 2kw or some other number below 4, for to the high voltage battery not having enough power to power the car at the required voltages any longer.

Again, our car could go that 100% rated range IF you could use all of that 4kw @ 290 watts per mile consumption. But not only is it not recommended, you also run the risk of the battery crapping out due to reduce power output.

 

[mongo]

At the top end,

I've heard rumors that the EPA test drives until the car won't go any further. What that means for the actual battery, is the point where the modules can no longer provide enough combined power to propel the car forward. Some have tried to drive beyond 0% to varying degrees of success. My guess is that for EPA testing, Tesla allowed them to use the 4kwh brick protection and take the battery to nominal charge = 0 to get their EPA rating. But in practice, they make 4kwh nominal 0% so that drivers don't dip into it. And dip into it at their own risk because you could have a module imbalance that the car would shut off at 2kw or some other number below 4, for to the high voltage battery not having enough power to power the car at the required voltages any longer.

Again, our car could go that 100% rated range IF you could use all of that 4kw @ 290 watts per mile consumption. But not only is it not recommended, you also run the risk of the battery crapping out due to reduce power output.

Wait, so you're second hand implying that Tesla has EPA cheat code?

More likely that the EPA range test uses less energy per mile than normal average driving. Good for comparison, not good for route planning.

 

[supratachophobia]

At the top end,


Wait, so you're second hand implying that Tesla has EPA cheat code?

More likely that the EPA range test uses less energy per mile than normal average driving. Good for comparison, not good for route planning.

Not cheating per say. The car really will go that range if you can use the 4kw that exists. And that 4kw is actually there. So maybe in their mind it's not actually cheating.

 

[ran349]

I've heard rumors that the EPA test drives until the car won't go any further. What that means for the actual battery, is the point where the modules can no longer provide enough combined power to propel the car forward. Some have tried to drive beyond 0% to varying degrees of success. My guess is that for EPA testing, Tesla allowed them to use the 4kwh brick protection and take the battery to nominal charge = 0 to get their EPA rating. But in practice, they make 4kwh nominal 0% so that drivers don't dip into it. And dip into it at their own risk because you could have a module imbalance that the car would shut off at 2kw or some other number below 4, for to the high voltage battery not having enough power to power the car at the required voltages any longer.

Again, our car could go that 100% rated range IF you could use all of that 4kw @ 290 watts per mile consumption. But not only is it not recommended, you also run the risk of the battery crapping out due to reduce power output.

But you admit you're just guessing. I doubt Tesla does that. If they did, I would call that cheating.

 

[mongo]

Not cheating per say. The car really will go that range if you can use the 4kw that exists. And that 4kw is actually there. So maybe in their mind it's not actually cheating.

If it only existed (is usable) for the EPA, I'd call that cheating...
I also would not want access to that last 4kW.

 

[David99]

But you admit you're just guessing. I doubt Tesla does that. If they did, I would call that cheating.

It's not a guess, it's measurable. If you drive the the rated range consumption, you will not get the range the car shows you. It will only go as far as the battery reaches the buffer protection point.
BTW, 85% of all EPA test cycles are done by the manufacturers themselves on a simulator.

 

[supratachophobia]

If it only existed (is usable) for the EPA, I'd call that cheating...
I also would not want access to that last 4kW.

*Exactly*, i don't want to drive on that 4kw brick protection and no one should have to in order to reach the stated numbers. But the fact remains that if you include it in the calculation, it fits perfectly for the EPA numbers. That has to be intentional

 

[supratachophobia]

But you admit you're just guessing. I doubt Tesla does that. If they did, I would call that cheating.

Totally guessing, however the math doesn't lie. If you take that brick protection and add it back into the equation, you hit you 100% number perfectly.

 

[ran349]

Totally guessing, however the math doesn't lie. If you take that brick protection and add it back into the equation, you hit you 100% number perfectly.

True, but that doesn't mean Tesla tests that way. I doubt they do. I have no problem meeting rated range in my car under certain driving conditions, and not just going downhill.

 

[mongo]

*Exactly*, i don't want to drive on that 4kw brick protection and no one should have to in order to reach the stated numbers. But the fact remains that if you include it in the calculation, it fits perfectly for the EPA numbers. That has to be intentional

To analogize, you can't use all the gas in an ICE tank either. I wonder how they do it, is the tank under rated (16 gallon is really 16.5), or is range over specified.
Not an excuse, mind you.

I wonder if part of their issue was that SOC should be based on Ah, but power depends on cell or pack voltage. So you use more SOC (amp hours) per mile the lower the pack SOC is. I think the trend was shown to be too linear for that directly. However, when you throw in that pack empty is based on cell voltage, it may have been an attempt to blend the two different constraints. The lack of accuracy is annoying though. Maybe the programmer didn't understand that the pack voltage changes?

 

[ran349]

It's not a guess, it's measurable. If you drive the the rated range consumption, you will not get the range the car shows you. It will only go as far as the battery reaches the buffer protection point.
BTW, 85% of all EPA test cycles are done by the manufacturers themselves on a simulator.

I've never seen where Tesla claimed an EPA consumption number (except that which includes charge/discharge losses), only rated miles. I know how you get the number by calculation, but if you can show me where Tesla states that, I would like to see it. I know the energy graph shows a line near that point, but that is a mistake, and I've never seen it stated by Tesla on any spec sheet.

 

[roblab]

And just why does someone need to drive to zero? The display clearly shows how little power is left, and yet the driver can't figure they need to charge?

Oh, wait. I loaned my car to someone like that. Drove to almost zero just a few miles from a charger, then turned around and drove back towards home, where there was no charger. That's when I stopped loaning my car. People are irrational and ignorant.

 

[supratachophobia]

To analogize, you can't use all the gas in an ICE tank either. I wonder how they do it, is the tank under rated (16 gallon is really 16.5), or is range over specified.
Not an excuse, mind you.

I wonder if part of their issue was that SOC should be based on Ah, but power depends on cell or pack voltage. So you use more SOC (amp hours) per mile the lower the pack SOC is. I think the trend was shown to be too linear for that directly. However, when you throw in that pack empty is based on cell voltage, it may have been an attempt to blend the two different constraints. The lack of accuracy is annoying though. Maybe the programmer didn't understand that the pack voltage changes?

ICE cars aren't rated for miles per tank though like electrics are. Would be an interesting comparison though.

 

[supratachophobia]

I've never seen where Tesla claimed an EPA consumption number (except that which includes charge/discharge losses), only rated miles. I know how you get the number by calculation, but if you can show me where Tesla states that, I would like to see it. I know the energy graph shows a line near that point, but that is a mistake, and I've never seen it stated by Tesla on any spec sheet.

I feel like wk057 find this in the firmware

 

[supratachophobia]

I've never seen where Tesla claimed an EPA consumption number (except that which includes charge/discharge losses), only rated miles. I know how you get the number by calculation, but if you can show me where Tesla states that, I would like to see it. I know the energy graph shows a line near that point, but that is a mistake, and I've never seen it stated by Tesla on any spec sheet.

Edit, they had to get this number from somewhere, even if it's not published anymore.

 

[mongo]

ICE cars aren't rated for miles per tank though like electrics are. Would be an interesting comparison though.

Sure they are, range is a listed spec.

2018 Ford Explorer Features & Specs | Edmunds
Or
2018 Ford Explorer AWD

 

[supratachophobia]

Sure they are, range is a listed spec.

2018 Ford Explorer Features & Specs | Edmunds
Or
2018 Ford Explorer AWD

Oh geez, have I been out of the ICE game that long?

 

[supratachophobia]

@Evoforce How do you explain the math then? (usable + brick protection) / EPA wpm = Range Remaining @ 100%, the number on the dash.....

 

[hiroshiy]

The real issue of this "Tesla dash percentage" is that even though I drive on flat land at the exact same speed with no wind, the consumption looks to be increasing as the battery is near and under 10%. This makes me nervous and makes the car unpredictable.

The car includes the last, unusable 4kWh in the dash percentage display above 80%.
The car reduces that unusable amount gradually as battery gets discharged.
At less than 10% the 4kWh is now excluded from the calculation.

So in the long drives like from 100% to 5%, I feel the consumption rate is increasing.

 

[supratachophobia]

The real issue of this "Tesla dash percentage" is that even though I drive on flat land at the exact same speed with no wind, the consumption looks to be increasing as the battery is near and under 10%. This makes me nervous and makes the car unpredictable.

The car includes the last, unusable 4kWh in the dash percentage display above 80%.
The car reduces that unusable amount gradually as battery gets discharged.
At less than 10% the 4kWh is now excluded from the calculation.

So in the long drives like from 100% to 5%, I feel the consumption rate is increasing.

It is increasing to adjust for that 4kw that isn't there. We are seeing the exact same thing.