100D vs 85D Range

[base698]

So the 100D is roughly 17.6% greater in capacity than the 85D. Why is the mileage 335 on the 100D? Seems like it should be 315, which is what the P100D is quoted as? Are the motors different? Some secret sauce?

 

[ambition]

I believe it has to due with usable energy in the pack

The 85 has about 77 available for use, 100 has about 100kw available to use

 

[JonG]

As ambition says, the 100D is more like 25% more capacity but slightly heavier

 

[twonius]

There was a recent motor update. Also there are some aerodynamic improvements on the facelift cars that extend range a bit
Tesla Quietly Revises Electric Drive Units On Model S, X

Also Tesla's numbering scheme doesn't really match the usable capacity.
Tesla’s hacked Battery Management System exposes the real usable capacity of its battery packs

 

[Tozz]

I believe it has to due with usable energy in the pack
The 85 has about 77 available for use, 100 has about 100kw available to use

Correct me when I'm wrong, but this seems incorrect. The 100 pack has the same reservations as any other pack, such as:

- Zero Mile protection ~5 kWh
- Brick protection ~5 kWh
- Daily Range vs. 100% Charge ~10 kWh

So a 100 battery pack, charged to 90% has about 80 kWh of power available for driving. You can top this off to 90 kWh if you charge to 100%. The remaining 10 kWh or the last 10% are reserved as a protection mechanism.

So the 85 pack has about 70 (90% SoC) or 77 (100S% SoC) kWh available. The 100 kWh pack about 80 kWh (90% SoC) or 90 kWh (100% SoC)

However, the 100 battery pack is really 102 kWh and the 85 pack is (i believe) somewhere around 82 kWh. The numbers are rounded off, but the difference counts for an extra 5 kWh.

Also, the zero mile protection is smaller percentages in a 100 pack than it is in a 85 pack. If the zero mile protection is 5 kWh regardless of pack size, that the protection is relatively bigger in the 85 pack than it is in a 100 pack

 

[jankratochvil]

- Zero Mile protection ~5 kWh
- Brick protection ~5 kWh

Those are together 4kWh and they are already considered in (excluded from) the "usable capacity" BMS report.:
As twonius above says, 85D has 77.5kWh usable (at 100%), 100D has 98.4kWh usable at 100%.

- Daily Range vs. 100% Charge ~10 kWh

You can subtract 10% of both but when you care about the capacity is when you drive far and then you charge to 100% so that does not count much.

 

[Tozz]

You can subtract 10% of both but when you care about the capacity is when you drive far and then you charge to 100% so that does not count much.

The 85 kWh pack is really 82 instead of advertised 85 kWh and the 100 pack is really 203. That accounts for a difference of 5 kWh which is about 24 km or 15 miles.

Furthermore, It would make sense that the "last mile protection" is equal regarding the pack size, so lets say 5 kWh. That is percentage wise less in a 100 pack then it is in a 85 pack. That way there is little "protection reservation" in a 100 pack.

But the true 82 kWh in an advertised 85 pack and the true 102 in an advertised 100 pack alone will account for about 15 miles, which is about the different the TS was wondering about. Add the relative smaller last mile protection in a 100 pack and you've accounted for the ilage difference

 

[SSonnentag]

I have no idea what accounts for all the differences in range, but I know that I compute my safe driving range by multiplying the number in the tens place of my battery percentage by 30 and I'm good to go. So 35% battery is easily good for 90 miles. I like simple.