Does EXT and STD Range have the same motors?

[Jimrpa]

Sure. But the SR battery has fewer cells, which is why the max discharge rate is lower. It's also why the max DCFC rate is 115kW instead of 150kW.

Aren’t you both saying the same thing? One person is saying the maximum discharge rate is a function of the number of kWh of the battery pack and the other person is saying that the maximum discharge rate is a function of the number of cells in the battery pack (assuming both battery packs use the same cells and everything else is equal)?

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[generaltso]

Aren’t you both saying the same thing? One person is saying the maximum discharge rate is a function of the number of kWh of the battery pack and the other person is saying that the maximum discharge rate is a function of the number of cells in the battery pack (assuming both battery packs use the same cells and everything else is equal)?

Sure, if both battery packs use the same cells. But in general terms, you can't say that a battery that has a high kWh capacity can have a high discharge rate.

 

[Jimrpa]

Something else I’m confused by P = V * I , right? And we’re working with a DC system so we don’t need to worry about any of that nasty power factor stuff or anything? We know V is constant for both battery packs, therefore, it should be impossible to draw more current out of the battery pack with the lower wattage?

 

[silverelan]

Doubt the laws of physics can be changed easily, lol.

Would be really neat to see the lighter weight SR AWD MMEs keeping pace with a 78kWh Polestar 2 or Volvo XC40 Recharge off the line and still have the range to outlast them on a single charge.

 

[KAustin]

I am curious if they are nerfing the acceleration of the STD Range via SW to give people a second reason to swallow the $5k up charge for about 69 extra miles?

There are more than just two reasons. As mentioned earlier, the maximum charging rate is 115 versus 150. Additionally, weather, especially, cold weather; using the heat and a/c all impact range significantly. Range can drop by as much as 30%.

 

[EVmodeler]

The ER pack is 94 cells in series, 4 in parallel.
The SR pack is 96 cells in series, (a little higher voltage), but 3 cells in parallel - so higher internal resistance and more voltage sag under high current load, and ~3/4 the current capability.
The motor torque is limited by the Inverter current output (not the same as battery current until you get to the corner or base speed point where max torque and max power meet)
So the SR is limited by battery current/power. Same for DCFC 115 kW 150 kW ER (3 cells vs 4 cells).
I think both vehicles use the same motor and inverter (would make sense) with some appropriate current limits for the SR vs ER battery.
See
https://www.macheforum.com/site/threads/mach-e-extended-range-battery-buffers-and-dcfc-limits.2431/
https://www.macheforum.com/site/threads/mach-e-extended-range-acceleration-modeling.2177/

 

[ChasingCoral]

There are more than just two reasons. As mentioned earlier, the maximum charging rate is 115 versus 150. Additionally, weather, especially, cold weather; using the heat and a/c all impact range significantly. Range can drop by as much as 30%.

The difference in the wiring and software both limit the power in and power out. The ER charges and discharges at a higher rate than the SR. The ER output to the motors exceeds the capacity of the Primary Drive Unit (rear motor), so the E4X has both the fastest output from the battery and a greater ability to use it. The combination makes the E4X the fastest non-GT. The GTs have an even larger Front Drive Unit so they can take full advantage of the ER batteries' output.

 

[solarity]

I wonder if you could ever upgrade the battery to a EXT range one in the future? I am betting it is modular.

 

[generaltso]

I wonder if you could ever upgrade the battery to a EXT range one in the future? I am betting it is modular.

It might be technically possible, but not practical.

 

[ChasingCoral]

I wonder if you could ever upgrade the battery to a EXT range one in the future? I am betting it is modular.

Sure. New battery $26,000. Plus labor.

 

[snikt]

Sure. New battery $26,000. Plus labor.

Sure hope this goes down over time? What if you need a new battery in 9 years?

 

[generaltso]

Sure hope this goes down over time? What if you need a new battery in 9 years?

You get a new car.

 

[snikt]

You get a new car.

Is time or mileage more of a wear item, or some combination of both?

What would have more battery wear, a 2 year old car with 100K miles or an 8 year old car with 50K miles?

 

[timbop]

The SR is a 75.7kWh pack (68kWh usable) which is objectively quite big so it shouldn't be a big leap to enable additional current to match the ER pack.

If the SR AWD motors had the same power as the ER version, it'd probably drop a decent margin off the 0-60 time.

The ER pack is objectively 30% larger, but the real difference is that those additional cells are wired in parallel. Same voltage but more available current. Any adjustment one chooses to make to the SR battery could also be done on the ER battery.

No games being played, just a matter of the laws of physics.

 

[generaltso]

Is time or mileage more of a wear item, or some combination of both?

What would have more battery wear, a 2 year old car with 100K miles or an 8 year old car with 50K miles?

Both. Total charge/discharge cycles probably has a bigger affect than age but it also depends how it’s cared for if it ages without much use.

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