How did they get to a 70kWh battery pack?

Three possibilities:

1. New cell chemistry.

2. More cells with old chemistry.

3. Old cells used within a wider voltage range (don't laugh this one off, IMO it's a real possibility)

4. Any combination of 1+3 or 2+3

Considering the following :
85 pack is 16 modules of each 6 series of 74 cells. Total is 402V and 7104cells
60 pack is 14 modules of each 6 series of 60 cells. Total is 352V and 5040cells (not sure about that one)

Since they want to simplify their line, making the same modules for all cars would make sense.

My guess? 14 modules of each 6 series of 74 cells (aka 14 of the 85kWh modules). Total would be 352V and 6216cells.

Only flaw to my plan is that this ends up being a 74kWh pack .

I say there is something interesting going on. Notice that the 70D EPA rating doesn't appear to take much of a hit in wh/mile like the 85 does. From the 60s 209 mile EPA spec, 70D would be 209*70/60=244miles. The 85 would have been 296 miles, with no weight gain penalty. So, for the 85, the weight gain penalty was 31 miles. For the 85D the penalty was only 26 miles. So somehow they got the 70D for only a 4 mile penalty over the 60 efficiency.

This makes it clear as mud, that Johan is right.

ahaer said:

I think I have those three choices in the poll at the top of the page. Which one do you think is most likely?

Click to expand...

Sorry, was posting from mobile (Tapatalk) so the poll doesn't show up.

Assuming the same anti brick buffer and below 0 mile buffer of 8.8 kwh, this would put the 70 in the 255 wh / mile range. Is that possible?

llavalle said:

Considering the following :
85 pack is 16 modules of each 6 series of 74 cells. Total is 402V and 7104cells
60 pack is 14 modules of each 6 series of 60 cells. Total is 352V and 5040cells (not sure about that one)

Since they want to simplify their line, making the same modules for all cars would make sense.

My guess? 14 modules of each 6 series of 74 cells (aka 14 of the 85kWh modules). Total would be 352V and 6216cells.

Only flaw to my plan is that this ends up being a 74kWh pack .

Click to expand...

I like your thinking. How about 13 of the 85 style modules. That would be 13/16 * 85kWh = 69 kWh. That is pretty close enough in Tesla specs to call it a 70... :wink:

Unfortunately that would lower the voltage of the pack, so I don't think so..

Nope, we are finally seeing some new cells! 100kwh packs here we come.

glhs272 said:

Unfortunately that would lower the voltage of the pack, so I don't think so..

Nope, we are finally seeing some new cells! 100kwh packs here we come.

Click to expand...

It's only a slight lowering of the Voltage, and if you are not looking for max performance, a fully charged DC Voltage of 325 Volts (13/16*400) is probably fine for normal driving.

Of course, new cells could be happening. If we assume these are new cells in a 60 configuration, that would be 70/60*85 or 99 kW for an 85 configuration. That is pretty close to 100, would love to see it!

My guess is new cells. In typical tesla fashion they will announce the 100kwh pack after they have real world data on these new cells.
The price increase can come from: Supercharging: $2,000 Navigation included: $1,250 less (from what I remember). AWD $5000
Meaning they included $8,250 worth of product for a $5000 price increase. Pretty cool of them

Seems like right now most people think this is just a repackaging of the same old cell. I think the clues we are given suggests otherwise. If they are just adding cells to the original 60 pack, then we should see a heavier car with a corresponding drop in efficiency. But from the new specs on the 70D, it looks like it is retaining near identical efficiency of the S60. This suggests the battery didn't get much heavier.

This portends potentially larger packs for the Model X.

AmpedRealtor said:

This portends potentially larger packs for the Model X.

Click to expand...

Exactly

AmpedRealtor said:

This portends potentially larger packs for the Model X.

Click to expand...

I like the ring of the X99, but the X100 is probably better for sales! (70/60*85=99)

Well, I'd like to think larger capacity (because that would mean a 95 or better pack in a few months), but what I think they did was put in an 85 pack and software limit it to 70. That way there's only one battery to make.

jerry33 said:

Well, I'd like to think larger capacity (because that would mean a 95 or better pack in a few months), but what I think they did was put in an 85 pack and software limit it to 70. That way there's only one battery to make.

Click to expand...

That would be interesting - did they ever offer the option to 40 owners to unlock the 60 packs?

Twiglett said:

That would be interesting - did they ever offer the option to 40 owners to unlock the 60 packs?

Click to expand...

Yup.

Twiglett said:

That would be interesting - did they ever offer the option to 40 owners to unlock the 60 packs?

Click to expand...

Yes. Tesla offers software upgrades to 60 kWh for all of the 40 kWh models built.

GSP

Why not just use the 85 battery pack and software limit it to 70 kwh? That's what I think they did.