Calling on the Battery and EV experts here, another SR vs ER question

[jbirdzee]

With the SR and ER trucks having the same torque but different horsepower, I am led to believe that the two versions share the same motors but you get more HP from the ER version because it runs at a higher voltage. Do I have that right?

My work commute is mostly highway, ~72mph, 55 miles each way. I have two questions:
1. Are we likely to see a drastic difference in the ER version of this truck combating bad aerodynamics and headwinds compared to the SR at freeway speeds?

2. With regards to pack cycling, (I do not have charging at work), with 110 miles round-trip I figure I'm cycling my battery 50% on each work day, possibly more with freeway speeds or in the winter. For trips to work I won't be hauling anything other than myself, but I am thinking I would be cycling the SR pack more than the ER battery and would end up hastening degradation. I would be interested in hearing a battery expert's thoughts on that.

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[adoublee]

With the SR and ER trucks having the same torque but different horsepower, I am led to believe that the two versions share the same motors but you get more HP from the ER version because it runs at a higher voltage. Do I have that right?

My work commute is mostly highway, ~72mph, 55 miles each way. I have two questions:
1. Are we likely to see a drastic difference in the ER version of this truck combating bad aerodynamics and headwinds compared to the SR at freeway speeds?

2. With regards to pack cycling, (I do not have charging at work), with 110 miles round-trip I figure I'm cycling my battery 50% on each work day, possibly more with freeway speeds or in the winter. For trips to work I won't be hauling anything other than myself, but I am thinking I would be cycling the SR pack more than the ER battery and would end up hastening degradation. I would be interested in hearing a battery expert's thoughts on that.

The ER probably supplies more current/amps to get the higher power, but I think you are on the right track regarding common motors.

Technically you will indeed cycle the batteries more with the same commute on the SR than the ER. But you probably won't notice the capacity degradation/fade if they have built in a buffer that is dynamic. This is something done with some LED light fixtures, as they tend to fade versus fail - they start with a dimmed 80% output to plan lighting around and then slowly release the dimming as hours of operation accumulate. My guess is you aren't going to notice loss of range on the SR until something like 100k miles. If you want a 200k+ vehicle it is probably worth getting the ER.

 

[RonTCat]

With the SR and ER trucks having the same torque but different horsepower, I am led to believe that the two versions share the same motors but you get more HP from the ER version because it runs at a higher voltage. Do I have that right? No. More current is available.

My work commute is mostly highway, ~72mph, 55 miles each way. I have two questions:
1. Are we likely to see a drastic difference in the ER version of this truck combating bad aerodynamics and headwinds compared to the SR at freeway speeds? No, aero load is not dependent on battery size.

2. With regards to pack cycling, (I do not have charging at work), with 110 miles round-trip I figure I'm cycling my battery 50% on each work day, possibly more with freeway speeds or in the winter. For trips to work I won't be hauling anything other than myself, but I am thinking I would be cycling the SR pack more than the ER battery and would end up hastening degradation. I would be interested in hearing a battery expert's thoughts on that. Yes, more cycling degrades a battery faster, but... cycling 80-20-80% is much easier on the battery than, say 100-10-100%. So if an ER battery can get you to the 80-20-80 condition every day, it will significantly outlive and out-degrade the SR battery.

 

[jbirdzee]

The ER probably supplies more current/amps to get the higher power, but I think you are on the right track regarding common motors.

Technically you will indeed cycle the batteries more with the same commute on the SR than the ER. But you probably won't notice the capacity degradation/fade if they have built in a buffer that is dynamic. This is something done with some LED light fixtures, as they tend to fade versus fail - they start with a dimmed 80% output to plan lighting around and then slowly release the dimming as hours of operation accumulate. My guess is you aren't going to notice loss of range on the SR until something like 100k miles. If you want a 200k+ vehicle it is probably worth getting the ER.

Thank you for this - The ER is on the safer side it seems.

No, aero load is not dependent on battery size.

For this I wasn't so much thinking the physical load or aero of the battery itself as the differentiator - After reading these forums and others about performance beyond the 0-60mph mark, I was curious if the SR truck would struggle more to counter aerodynamic drag because its available discharge current is lower than the ER counterpart.

Thank you for the info and setting me straight.

 

[DadBald]

If you need more than 426 HP to overcome aero drag, you're going too fast.

 

[RonTCat]

Thank you for this - The ER is on the safer side it seems.


For this I wasn't so much thinking the physical load or aero of the battery itself as the differentiator - After reading these forums and others about performance beyond the 0-60mph mark, I was curious if the SR truck would struggle more to counter aerodynamic drag because its available discharge current is lower than the ER counterpart.

Thank you for the info and setting me straight.

The vehicle has 20 times the horsepower needed to overcome aero at 70mph, LOL.

 

[Blainestang]

The vehicle has 20 times the horsepower needed to overcome aero at 70mph, LOL.

I'm sure it will have *plenty* of power, but it is interesting that the 480hp Mach E GT is only as fast as a Dodge Ram R/T from 60-100mph, despite having almost 100hp more, better aero, and 500lb less weight.

Hopefully Ford figures out why the Mach E GT is falling on its face at high speeds (relative to its power level) and avoids this issue with the Lightning.

 

[adoublee]

For this I wasn't so much thinking the physical load or aero of the battery itself as the differentiator - After reading these forums and others about performance beyond the 0-60mph mark, I was curious if the SR truck would struggle more to counter aerodynamic drag because its available discharge current is lower than the ER counterpart.

Batteries have a nameplate of maximum rate at which electrons can be drawn (current) from the electron "tank". There are various points at which a manufacturer might set this rating, but you can think of increasing rate of electron draw as increasing stress on the battery, which is of minimal impact within a range of electron delivery but eventually starts increasing exponentially.

At a fixed vehicle speed, the ratio of delivered electrons to electron "tank" will be higher with the SR battery, meaning it is technically more stress on the battery. I'm not saying it is stressful to the point you should be concerned about it, as it is probably a ways from the point at which stress becomes exponential (and active cooling helps manage as well).

Which vehicle stresses the battery during acceleration more is harder to estimate as there are differences in weight and current allowed to be drawn from SR and ER batteries, on top of the electron "tank" differences. But in general, electrical/thermal stress of a fixed current draw will always be lower the larger the Ah/kWh rating of the battery is

Long story short, the ER battery can be considered more robust if you will be putting a lot of highway miles on though it is hard to quantify the long term impact.

 

[DadBald]

The high-speed limitation you're referring to has to do more with the motor performance than the battery pack. Motors become less powerful the faster they go - all the torque is on the low end, in stark contrast to an ICE which has zero torque at zero RPM and the most way up it's rev profile.

 

[metroshot]

For highway driving at high speeds, the ER battery makes more sense as there is less regen and need for more miles.

On the contrary, for my daily driving in LA traffic, I'd get the SR battery as my commute is short and the battery regen is higher (coasting & braking).

My current PHEV gets way more miles on EV when driving around town but when freeway speeds over 60MPH, I kick in the ICE engine to take over (EV range sucks at sustained highway speeds) and I save the EV battery for congested driving.

 

[Roy2001]

My work commute is mostly highway, ~72mph, 55 miles each way.

SR could be pretty tight for you. During winter, assume no battery degradation, you charge to 210 miles, if you main drive at <65mph, and you only use heat moderately, and you want to have 30 miles left when you get home, I would say, the most range you can squeeze out is 120-140 miles.

If you drive at 72mph, that would be definitely less than the 110 miles you need, no need to mention if you have do something else during the day.

So get the ER.

 

[RonTCat]

I'm sure it will have *plenty* of power, but it is interesting that the 480hp Mach E GT is only as fast as a Dodge Ram R/T from 60-100mph, despite having almost 100hp more, better aero, and 500lb less weight.

Hopefully Ford figures out why the Mach E GT is falling on its face at high speeds (relative to its power level) and avoids this issue with the Lightning.

There is nothing to figure out, except how badly you want to nuke the battery. It's more of a matter of gambling on warranty battery replacements by crushing your battery to get a max power curve.

 

[Blainestang]

There is nothing to figure out, except how badly you want to nuke the battery. It's more of a matter of gambling on warranty battery replacements by crushing your battery to get a max power curve.

Yeah, there’s something to figure out when the 480hp Mach E GT Performance traps the same speed as the regular 346hp Mach E ER and takes just as long to get from 60-100mph.

If the battery can’t handle any more than that, then the thing to figure out is why the battery is so temperamental.

 

[EaglesPDX]

Have similar commute with the Tesla which has 300 mile range, sames F150 ER.

You'll want the ER for every reason.

1. Battery degradation will be less because the percentage of discharge will be less.
2. Bad weather range will be 20-50% less.
3. If you have a load or tow, range will take a big hit. I expect 50% towing my 5k boat.
4. Resale value.

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