Tesla's 85 kWh rating needs an asterisk (up to 81 kWh, with up to ~77 kWh usable)

[pupik]

First: tests show the P85D has about 415 kW of power or about 556 hp.
Second: Most (if not all) car manufacturers use the total theoretical capacity of the battery, not the usable (Volvo, Nissan, BMW, VW just to name a few).
Third: There are standardized tests (NEDC in Europe) that make it possible to compare vehicles. It is common knowledge that these tests do not represent realistic daily driving. This is the same for every car, however these tests make it possible to compare vehicles.

Tesla would be crazy not to use the outcome of the standardized test for range if all other car manufacturers do.

I do however agree that Tesla should add an option to use (for example) the average consumption of the car to calculate the range. I think this would help a lot of people better understand how far they can drive at any given moment.

I just wanted to express my feelings...
I chosen a type of car following by parameters...
...and now I am finding out that these parameters are not real.
I feel betrayed. Otherwise I have to admit...
...that I love my car because it is excellent :smile:
hmmm...:crying:

 

[tomas]

I just wanted to express my feelings...
I chosen a type of car following by parameters...
...and now I am finding out that these parameters are not real.
I feel betrayed. Otherwise I have to admit...
...that I love my car because it is excellent :smile:
hmmm...:crying:

that is what disturbs me about this thread and its ilk. owners who love their cars are being made to feel cheated by a handful of angry, conflicted people who want to rage about standards. I buy the HP thing. Though it is a spec vs a performance measure, the full gamut of performance measures were not published (eg 30-60 and other passing speeds) so a buyer could misinterpret motor hp spec. The rest of this is blah blah blah.... Negativity that has no place for me! Battery capacity interesting, and OPs research is fine... Except title, and incitement to get it on. Capacity is a spec... Range is the performance metric. It is measured by EPA using standard tests. Nobody achieves it in real life (ICE or BEV) except with neutered driving and/or ideal conditions. Nothing deceptive.

 

[Johan]

that is what disturbs me about this thread and its ilk. owners who love their cars are being made to feel cheated by a handful of angry, conflicted people who want to rage about standards. I buy the HP thing. Though it is a spec vs a performance measure, the full gamut of performance measures were not published (eg 30-60 and other passing speeds) so a buyer could misinterpret motor hp spec. The rest of this is blah blah blah.... Negativity that has no place for me! Battery capacity interesting, and OPs research is fine... Except title, and incitement to get it on. Capacity is a spec... Range is the performance metric. It is measured by EPA using standard tests. Nobody achieves it in real life (ICE or BEV) except with neutered driving and/or ideal conditions. Nothing deceptive.

I agree with this post wholeheartedly. You are a reasonable man. How do you feel about the fact that we have strong indications that Tesla have been very self serving in the way they been rounding up and down to the nearest 0/5 when assigning the 60/70/85/90 numbers, very likely in order to exaggerate the difference between the different packs and thus (I assume) up sell the larger ones?

 

[eye.surgeon]

Who cares. Buy a different car if you're bothered.

 

[pupik]

This was the only moment when the lie was pleasing (0km = +10km)
I did some test on my P85D/2015/v7.1 on range 0km with connected scan on CANbus
Notice that I drove 10 km more from 0km
When 0km showed for the first time I had 4kW left (energy buffer?)
when CAN showed 0kW I drove > 8km (5miles)
then the car was completely dead
The worst thing was that after exhaustion to 0kW I cannot release the handbrake to let push the car from a crossroad.

SOC=0% ODO=14039km

SOC=0% ODO=14048km

 

[tomas]

I agree with this post wholeheartedly. You are a reasonable man. How do you feel about the fact that we have strong indications that Tesla have been very self serving in the way they been rounding up and down to the nearest 0/5 when assigning the 60/70/85/90 numbers, very likely in order to exaggerate the difference between the different packs and thus (I assume) up sell the larger ones?

for me, decision to buy P85 in 2012 vs 60 was based on significantly more: range, acceleration. Both of which were as advertised and fairly priced. My point is, real performance metrics are meaningful and ample in comparing models. Capacity irrelevant except as manifested in range.

 

[Johan]

for me, decision to buy P85 in 2012 vs 60 was based on significantly more: range, acceleration. Both of which were as advertised and fairly priced. My point is, real performance metrics are meaningful and ample in comparing models. Capacity irrelevant except as manifested in range.

But how do feel about the numbers? Do you think the designations are fair or unfair. Or are you indifferent?

 

[Pajda]

This was the only moment when the lie was pleasing (0km = +10km)
I did some test on my P85D/2015/v7.1 on range 0km with connected scan on CANbus
Notice that I drove 10 km more from 0km
When 0km showed for the first time I had 4kW left (energy buffer?)
when CAN showed 0kW I drove > 8km (5miles)
then the car was completely dead
The worst thing was that after exhaustion to 0kW I cannot release the handbrake to let push the car from a crossroad.
full charge SOC 0-100% -> only

It seems to me, that you just confirmed everything what was stated in the first Wk post in this thread.

Your car total batery capacity is 81,6kWh = so your cells are ~11,48Wh/3200mAh (It fits with specification of NCR18650BE cells).
Your car total usable capacity is 77,6kWh (4 kWh energy buffer is forever locked for you)
Your car range indicator is "dumb" (in this particular case it has incorrectly calculated available range and showed you about 10km less than it was possible to drive = there is no zero mile protection).

After you have fully discharged the total usable capacity 77,6kWh the car was automatically "bricked" via BMS.

 

[tomas]

But how do feel about the numbers? Do you think the designations are fair or unfair. Or are you indifferent?

Indifferent. I don't feel screwed or misled because I got the range I paid for and that's the meaningful metric. I don't buy the upsell accusation because there were/are enough real, measurable differences to justify price.

lemme add: I got more range than I ever expected via a much broader, free supercharger network than I expected or was promised in 2012.

 

[Johan]

Indifferent. I don't feel screwed or misled because I got the range I paid for and that's the meaningful metric. I don't buy the upsell accusation because there were/are enough real, measurable differences to justify price.

Completely valid position. Thanks for replying.

 

[Pajda]

After you have fully discharged the total usable capacity 77,6kWh the car was automatically "bricked" via BMS.

By the way, it would be interesting to find out how long after that the DC-DC converter will run. Because ~240W is not negligible power drain from the main battery.

 

[MarcG]

But how do feel about the numbers? Do you think the designations are fair or unfair. Or are you indifferent?

Even though this question was for tomas, I'd also like to answer it since I feel the same way as him about EPA-tested range/real life performance vs. advertised capacity.

I personally think the designations are fair, but really don't care about the actual capacity number. If the numbers at launch were 40/60/80, it may have made more sense but it most likely would not have changed anyone's decision to get a 60 over an 80 since the range would have still been 208 vs. 265.

They could have named them 40/60/90 or anything else for that matter, I really don't think it makes a difference at all. For those math types who like to understand the ratios and whatnot it may be puzzling, but at the end of the day 208 is 208 (for the "60") and 265 is 265 (for the "85") no matter what the stated capacity is.

 

[tomas]

Completely valid position. Thanks for replying.

Thanks for civil discussion! Nice to see you posting here.

 

[flathillll]

No it wouldn't because the car will never allow the pack to be drawn to 0 SOC.



This is true, and it's why the name plate rated capacity of a cell probably never reflects it's actual real world capacity. I think what some people need to realize is that this is a new industry, (EV's), and some of the standard practices such as pack ratings probably need to be adjusted for the market. Tesla took the nameplate cell capacity from the manufacturer and rated it's pack accordingly, as is standard in the battery industry. No deception intended, IMO.

the car will switch into a ultra low power mode (everything off but the bmb's and they even go down and cells continue to self discharge) and you can drain it to zero. the reserve capacity is technically usable capacity in storage, just not while driving. try driving to zero miles and park your car in the desert. you will use the "reserve" capacity fairly fast in that situation as self discharge is dependent on temp

 

[pupik]

It seems to me, that you just confirmed everything what was stated in the first Wk post in this thread.

Your car total batery capacity is 81,6kWh = so your cells are ~11,48Wh/3200mAh (It fits with specification of NCR18650BE cells).
Your car total usable capacity is 77,6kWh (4 kWh energy buffer is forever locked for you)
Your car range indicator is "dumb" (in this particular case it has incorrectly calculated available range and showed you about 10km less than it was possible to drive = there is no zero mile protection).

After you have fully discharged the total usable capacity 77,6kWh the car was automatically "bricked" via BMS.

yes exactly...
and still look at cell voltages and battery current below...
min cells voltage while driving before "game over" = 2.6V ! max. for charge 4.2V
so, max. capacity available
so, my car cells working 2.6-4.2V, only protection is "MaxChargePower and MaxDischargePower parameters"
attention no capacity reserve!

SOC=0% ODO=14039km
here main current standard (limit = MaxDischargeCurrent)

SOC=0% ODO=14048km
here main current 0A -> for main battery game over (only internal BMS current)
... and all work on 12V battery
but still handbrake is dead, I do not understand... :cursing: why?

 

[MarcG]

Pupik, did you try "tow mode"? That should have released the handbrake and put the drive in neutral.

 

[flathillll]

the car is not bricked by the BMS when you hit the reserve. Bricking a car means you have discharged the cells so low that they are damaged and not safe to recharge. this was definitely possible on a roadster but no one knows for sure if the same is true with the model s cells as they may use "zero volt" tech from quallion

 

[kennybobby]

...
min cells voltage while driving before "game over" = 2.6V ! max. for charge 4.2V
so, max. capacity available
so, my car cells working 2.6-4.2V, only protection is "MaxChargePower and MaxDischargePower parameters"
attention no capacity reserve!
...
here main current 0A -> for main battery game over (only internal BMS current)
... and all work on 12V battery
but still handbrake is dead, I do not understand... :cursing: why?

1. The lowest i can see is 2.888, not sure where the 2.6 comes from?

2. You will need an external 12V battery to connect to the terminals behind the front grill to hopefully get enough power to turn on the center console and get to the menu to toggle into 'towing' mode, which releases the parking pawl to allow it to roll in neutral, then get it towed home so you can charge the pack.

 

[AWDtsla]

The worst thing was that after exhaustion to 0kW I cannot release the handbrake to let push the car from a crossroad.

Isn't this power by the 12V? Why did that happen?

 

[pupik]

Pupik, did you try "tow mode"? That should have released the handbrake and put the drive in neutral.

no, "tow mode" unavailable
I tried many times to press brake
nothing... :cursing:

1. The lowest i can see is 2.888, not sure where the 2.6 comes from?

when car stopped 2.888 and while driving min. 2.6V !

Isn't this power by the 12V? Why did that happen?

only test -> when this happens in the future
...and good info for all users, I think...