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

[rns-e]

It seems to me the 90's will require not one (*) asterisk but two (**). Something is rotten in the state of Denmark...

There is a lot things that are rotten in Denmark - but that is a whole other story and not for this forum

Could Tesla be moving away from model number being the same as the battery size? The same way that BMW moved away from model number telling the size of the engine?

 

[Johan]

There is a lot things that are rotten in Denmark - but that is a whole other story and not for this forum

Could Tesla be moving away from model number being the same as the battery size? The same way that BMW moved away from model number telling the size of the engine?

1. Just to clarify if someone is wondering, "Something is rotten in the state of Denmark": this line spoken by Marcellus (and not Hamlet as is commonly believed) is one of the most recognizable lines in all of Shakespeare's works. Just thought of it as I typed my post.

2. Your suggestion to move away from battery size labelling makes a lot of sense, it's something I've advocated for quite some time. If they insist on using a number why not rather the EPA rated range number. Or some performance related number.

 

[rns-e]

ad 1: I know ;-)

ad 2: The numbers 40,60,75,85 and 90 combined with the letters p and d does a very good job of descriping the different trimlevels, although it may be confusing when the letters are accurate and the numbers not so much. But it is still better than some of the Chinese cars

 

[jaguar36]

Could Tesla be moving away from model number being the same as the battery size? The same way that BMW moved away from model number telling the size of the engine?

I wouldn't say they are moving away from it, the original 85 only has a 80kwhr battery. In addition they are advertising the 90 as having a 90kwhr battery.

 

[SageBrush]

• Tesla's "85" kWh pack consists of 16 modules of 444 cells for 7,104 total cells.

• Tesla's "60" kWh pack consists of 14 modules of 384 cells for 5,376 total cells.

Apologies for now pointing out the obvious ...

85/60 = 1.416
7104/5376 = 1.321

So unless different cells were used, either the '85' pack was less or the '60' pack was more.

And while not condoning what I also see as a misrepresentation of pack size, it seems fair to say that a buyer of an '85' could reasonably expect to obtain 41.6% longer range than a '60' model (85/60.) If Tesla programmed in a 4 kWh anti-brick to the '60' for a usable 56 kWh, then the '85' should proportionately have 56*1.41, = 79 kWh usable capacity.

Does it ?

 

[jaguar36]

Apologies for now pointing out the obvious ...

85/60 = 1.416
7104/5376 = 1.321

So unless different cells were used, either the '85' pack was less or the '60' pack was more.

And while not condoning what I also see as a misrepresentation of pack size, it seems fair to say that a buyer of an '85' could reasonably expect to obtain 41.6% longer range than a '60' model (85/60.) If Tesla programmed in a 4 kWh anti-brick to the '60' for a usable 56 kWh, then the '85' should proportionately have 56*1.41, = 79 kWh usable capacity.

Does it ?

No, as the thread title states it only has 77kwhr usable.

 

[scaesare]

the original 85 only has a 80kwhr battery.

While that's been asserted by folks running their own battery tests, nobody has an official manufacturer's rating for the battery used by Tesla. So that's a matter of some debate.

 

[SageBrush]

No, as the thread title states it only has 77kwhr usable.

If correct then I would view the discrepancy as ~ 2 kWh

 

[MuppetOwl]

Can bus data from a new 85D with only 300km on odo.

Here is can bus data from 60-90 batteries..

90 = 84.9 + 4 kWh = 88.9 kWh
85 = 79.3 + 4 kWh = 83.3 kWh
70 = 68.5 + 4 kWh = 72.5 kWh
60 = 57.0 + 2.8 kWh = 59.8 kWh

 

[FlatSix911]

Can bus data from a new 85D with only 300km on odo. View attachment 172279 Here is can bus data from 60-90 batteries..

90 = 84.9 + 4 kWh = 88.9 kWh
85 = 79.3 + 4 kWh = 83.3 kWh
70 = 68.5 + 4 kWh = 72.5 kWh
60 = 57.0 + 2.8 kWh = 59.8 kWh

Interesting data ... Battery % without buffer:

90 = 94.3%
85 = 93.3%
70 = 97.8%
60 = 95.0%

 

[SageBrush]

Can bus data from a new 85D with only 300km on odo.

View attachment 172279

I don't know how to read this. How many kWh usable at full charge ?

 

[apacheguy]

Can bus data from a new 85D with only 300km on odo.

View attachment 172279

Here is can bus data from 60-90 batteries..

90 = 84.9 + 4 kWh = 88.9 kWh
85 = 79.3 + 4 kWh = 83.3 kWh
70 = 68.5 + 4 kWh = 72.5 kWh
60 = 57.0 + 2.8 kWh = 59.8 kWh

Very interesting. I find this troubling as the rest of us with 85s have seen no more than 76 kWh with fairly new packs. CAN3 on mine reports full energy of 75.5 kWh with a 4.0 buffer. Am I to believe my pack has already lost 4 kwh with only 14,000 miles? Doesn't seem right.

Also interesting to me was that energy remaining exceeded nominal full pack energy. Ah, ok that is ideal, i see.

 

[MarcG]

Can bus data from a new 85D with only 300km on odo.

View attachment 172279

Here is can bus data from 60-90 batteries..

90 = 84.9 + 4 kWh = 88.9 kWh
85 = 79.3 + 4 kWh = 83.3 kWh
70 = 68.5 + 4 kWh = 72.5 kWh
60 = 57.0 + 2.8 kWh = 59.8 kWh

The way I read your screenshot is that 79.3 kWh INCULDES the 4 kWh buffer, since it says "Full Pack Energy".

So with that in mind, the available pack energy for driving, EXCLUDING the 4 kWh buffer, would be 75.3 kWh. This matches nicely with my stats that showed my P85D's pack at 75.2 kWh when it was new (now sitting at around 70 kWh after 32k miles).

Thoughts?

 

[apacheguy]

No. Nominal full pack energy does not include the bricking protection.

 

[MarcG]

No. Nominal full pack energy does not include the bricking protection.

Can you please point me to any such evidence? Just trying to understand.

I specifically remember when my car was new, less than 1000 miles on the odometer, I took a nonstop trip from 100% to 0% SoC (had 2 miles left of rated range left) and the trip meter showed 75 kWh since last charge.

 

[MuppetOwl]

Nominal full pack energy does not include the buffer.

When you are driving 100-0 and get 74-75 kWh out of the battery its because of losses I think. The loss looks to be around 4-5% or 6-7% if you often uses max the power of the car and often drive at high speed.

 

[MuppetOwl]

This is charge/discharge data from my P85D

As you can see my car has charged a total of 8380.62 kWh and discharge 7851.1 kWh. That is a loss of around 6%
This I think is losses in motor/heat

 

[diamond.g]

Can bus data from a new 85D with only 300km on odo.

View attachment 172279

Here is can bus data from 60-90 batteries..

90 = 84.9 + 4 kWh = 88.9 kWh
85 = 79.3 + 4 kWh = 83.3 kWh
70 = 68.5 + 4 kWh = 72.5 kWh
60 = 57.0 + 2.8 kWh = 59.8 kWh

Just curious, does this mean that it is possible the new MX 75D pack is just a rebranded 70?

 

[Pajda]

This is charge/discharge data from my P85D

As you can see my car has charged a total of 8380.62 kWh and discharge 7851.1 kWh. That is a loss of around 6%
This I think is losses in motor/heat

That difference means only that there is measured energy of the both charging and discharging process by the BMS. For example if you have a single 12.6 Wh cell, you must always supply 12.8-13 Wh (depends on charging rate) of energy for its full charge. Only then you are able to discharge the nominal 12.6 Wh from the cell.

So the BMS measures all energy flowing in and out of the battery. The only losses which are not measured by the BMS is the self-discharge current of the cells itself but it is not a significant value

 

[MarcG]

Nominal full pack energy does not include the buffer.

When you are driving 100-0 and get 74-75 kWh out of the battery its because of losses I think. The loss looks to be around 4-5% or 6-7% if you often uses max the power of the car and often drive at high speed.

This makes no sense to me. Driving faster is reflected in the Wh/mi consumption and higher total energy (kWh) used numbers. Max battery power was not even available at the time. Anyway, the car reports the amount of energy drained from the battery from the BMS, so that's all pre-"losses" which are downstream of the battery.

The fact that driving 100% to 0% SoC only yields total usage of 75kWh is the strongest evidence that this number is the truly available amount of energy available to the driver for a trip. The 4 kWh buffer is on top of this number, giving us a total battery capacity of 79 kWh as reported by the CAN bus.

By the way, I just read an interesting and somewhat related article about 85 vs 85D efficiency and battery capacity this morning:

All-wheel-drive Tesla electric cars rated more efficient, but how?

One paragraph that especially caught my attention:

In the EPA tests, the dual-motor 85D dual-motor 85D used 10 percent less out-of-the-wall-plug electricity than the single-motor 85.