Range Extender can be turned off / disabled via menu setting screen

[dleepnw]

awesome if true. makes sense for daily driving to turn that off and go fully electric. of course it means you're just carrying around extra dead weight but not a bad trade off for getting an extra 150 miles when you need it for road trips to reduce charging stops.

 

[M3_R2]

Stating the obvious, but If your towing range is 250 miles and you leave with a full tank and full battery then after about 250 miles you will be out of battery charge and gas. The only way you'll be able to do that all over again is with a full tank and a full charge of course. Will you be able to gas up only and on your way? I doubt it. The REX isn't going to be powerful enough to provide 1:1 charge/discharge. It will charge the battery far slower than you will be requiring electrons. So you will have to sit tight and charge and then ideally fill up again. How long that will be, I'm not sure but it could be a while.

Also note that while driving, most if not all the time, the REX will be running to get you that 250 miles. Otherwise, you will deplete the battery way before you run out of gas. Hopefully it's quiet!

But at least you have this as an option which reduces range anxiety. If you are in a hurry, an ICE tow vehicle likely remains the best option till battery density and charge speed increases and prices decrease.

If your daily drive is using only the battery, then definitely go for it. You can recharge anywhere you have gas but if you are towing, it won't be seamless without needing to stop and charge from the REX.

At least that's my interpretation. Feel free to correct...

 

[SpaceEVDriver]

I like this breakdown but I disagree with the final paragraph. My opinion is the RE will charge the battery but it's primary purpose is to provide enough power to the vehicle to keep it moving. So, at a minimum I believe the generator will have the same max output power as the wheels.

There's no way a range extender will provide enough power to keep the battery at a given state of charge during max power output to the wheels. With a planned 3.5 second 0-60 time, even the Ram TRX 6.2L V8 cannot keep up (4.5 seconds 0-60). This isn't a drivetrain engine, it's a generator. It may be finely tuned to provide recharge of the batteries, but it's not in parallel with the drive motors. And if it were as large as an engine providing that kind of acceleration, there would be no frunk.

If they're advertising 350 mile BEV range and 500 mile EREV range, then they have to be planning to charge while driving. As others have pointed out, there will likely be a battery module or two removed to fit the gasoline generator in.

They won't be waiting for the battery to completely discharge before activating the gas generator (otherwise it's a 150 mile range with self-recharge capability, not extended range capability). If the posted capability

I’m guessing this generator is probably 5-7kW charge rate. Maybe less. Its only purpose is to charge the main battery, not drive the vehicle.

I agree.

Say the EREV's smaller battery has a total range of 250 miles. When the battery is down to 60% (the vehicle has gone 100 miles and used 40% of its charge), the generator powers on and starts providing power to the battery. This doesn't increase the battery state of charge, but rather decreases the discharge rate. In this scenario, the original discharge rate was 40%/100 miles = 0.4%/mile. If the battery is now being charged at 0.25%/mile, and discharged at 0.4%/mile, the net discharge rate while the generator is on is 0.15%/mile. There's 60% remaining, so that gives the vehicle another 400 miles (60% / 0.15%/mile = 400 miles), and a total of 500 miles.

If (in my made-up scenario) the battery range is 250 miles and the assumed efficiency of the vehicle is similar to the R1S or Lightning (say, 2 miles/kWh), then that means the battery would have a capacity of 125 kWh and the generator will provide 31.25 kWh for 400 miles. Assuming 400 miles of driving at 60 mph, that's about 6.67 hours, the generator will provide about 5 kW, which is a nice-sized generator--not too big and not undersized.

 

[justinjas]

They've said the max torque of the EV is 1000+ ft/lbs. Based on similar number from Rivian, we can guess on the order of 800hp. The gas generator will not produce anywhere near that kind of power.

But the car won’t be outputting max torque all the time. It’ll be acting like a normal EV , sometimes outputting very little while coasting, sometimes charging the batteries while breaking, and sometimes for very short bursts outputting max torque. The harvester can just run constant recharging the battery the entire time regardless of what’s happening at the wheels. It doesn’t need to match the electric engine at max output it just needs to match the output over a long drive to keep energy in the batteries.

 

[chopsui]

But the car won’t be outputting max torque all the time. It’ll be acting like a normal EV , sometimes outputting very little while coasting, sometimes charging the batteries while breaking, and sometimes for very short bursts outputting max torque. The harvester can just run constant recharging the battery the entire time regardless of what’s happening at the wheels. It doesn’t need to match the electric engine at max output it just needs to match the output over a long drive to keep energy in the batteries.

Please read the quote I was responding to.

 

[No_Name5330]

There's no way a range extender will provide enough power to keep the battery at a given state of charge during max power output to the wheels. With a planned 3.5 second 0-60 time, even the Ram TRX 6.2L V8 cannot keep up (4.5 seconds 0-60). This isn't a drivetrain engine, it's a generator. It may be finely tuned to provide recharge of the batteries, but it's not in parallel with the drive motors. And if it were as large as an engine providing that kind of acceleration, there would be no frunk.

What does 0-60 have to do with "keeping up" with the discharge rate? Also 0-60 is influenced heavily by torque and the ability to apply power immediately, while a generators focus is to put out sustained power at a constant rate. And to have a real world example; there are cars like the Audi SQ5 Prestige which make 349 hp and 4.8 second 0-60 and this would make FAR less power than the Ram TRX.

In a quad motor Rivian, the front two motors produce 415 hp (309 kW) and 413 ft-lb (560 N⋅m) of torque while the rear two motors produce 420 hp (310 kW) and 495 ft-lb (671 N⋅m) of torque for a total of 835 hp and 723 kW. And to play your game, a 0-60 of 3 seconds.

Assuming that one hp is 0.735 kW, and a TRX has 702 hp, then it could put out 515.97 kw which unless your going balls to the wall and using all the power there is CONTANTLY; which is impossible because of thermal limits and many other simple reasons. There is just no way you'd be exceeding the power output of the Hellcat from realistic use or even high speed towing.

I'm hoping that you were just going to the extremes to use the Hellcat as a generator and yes you are correct that it wouldn't be possible for it to keep up with the discharge rate if you were using full power. But that usage is just not realistic. I'm guessing that we are going to see a generator that generates ~250 kw and can keep up with day to day usage.
Have a good day

 

[justinjas]

Please read the quote I was responding to.

Ah sorry read it in a vacuum, guess we are saying the same thing then, it won’t match the max output at the wheels cause it doesn’t need to since it runs independently and can run at constant rpm.

 

[colinnwn]

One of the vloggers at the reveal asked a Scout spokesperson who said the EREV version was cheaper to produce than the BEV because the EREV would have 150 miles of electric range. This was to make room for the generator and gas, and not add to the price. The generator gets you the 350 miles.

I'm guessing the generator will be in the 100 kw range so if you are towing close to the max and you get to 250 miles depleting both, you can gas and go without having to wait a long time for the generator to recharge the battery in the middle of nowhere. For example the Ramcharger generator is 130 kw.

That would mean if not towing, then the generator would be able to power the truck and charge the battery at a slower rate.

If I'm wrong and the generator is much smaller, I may not convert my reservation to a purchase.

 

[commadorebob]

They've said the max torque of the EV is 1000+ ft/lbs. Based on similar number from Rivian, we can guess on the order of 800hp. The gas generator will not produce anywhere near that kind of power.

Let me clarify my statement. I believe the generator will have a max output power needed to drive the wheels. Will it tow? No. Will it climb a mountain? No. But if you are driving at reasonable interstate speeds, I believe the RE will 100% allow for unlimited range as long as you keep it filled with gas.

What is the basis of my belief? The fact that is how pretty much every RE has ever worked and the fact that at 75mph, my I-4 truck averages only 1,500RPM. The RamCharger is going overboard with a V6 so it can tow while also completely charging the batteries. But a vehicle in motion doesn't actually take that much power to stay in motion.

For most people, it won't matter. The RE will kick in before the batteries get too low and the range is sufficient that bladder size will have you stopping before the 500 miles are up. Since it uses the Tesla standard, there should be no problem finding a charging port. Hell, you could stop at Buccees and top of the gas and battery in one stop.

All that to fall back to my original statement: until Scout releases specs, we do not know.

 

[colinnwn]

Yeah pretty much everything we know is speculation, even what Scout has shown is subject to change since they said they hoped the samples were 80 or 85 percent final.

For my purposes I don't need the Scout to charge while towing a full load going up a hill. But I absolutely want it to be able to indefinitely tow a 3,500 lb camper on flat ground against a stiff headwind, with maybe enough reserve to trickle charge the battery. I'd estimate that's going to be in the 80-100 kw range.

That would cut the total range to the 250 mile area. I go out to west Texas regularly. Good luck finding a charger and I don't want to risk all the damaged chargers, or inconvenient chargers you have to unhook to access, or one being ICEd. I also wouldn't want to wait around to charge that often.

Now if I go to Colorado towing a heavier load it would be OK if I had to find a charger after a mountain pass or had to slow down a little. Someone did the math and said due to battery chemistry you'd probably need closer to 200 mile equivalent battery range to fully capture regenerative braking while towing in any kind of mountain. It's ok not being able to do that as long as the generator is big enough.

I'd also be concerned if people figure out the Scout EREV isn't capable of indefinite towing a decent load, the kind of people who really want a full gas option but are kinda on board with an EREV are gonna back out.

I know this is nothing we can answer or solve, but I hope the Scout Team is thinking about it.

 

[Rouse]

Things that are pretty well confirmed:
-the battery will have about 150 miles of range
-the gas tank and generator have the capacity to generate enough electricity to fill the battery around 2 1/3 times

Anyone that’s spent much time with an EV knows that use (speed, temperature, towing, braking, etc) can greatly influence the rate you’re using the charge in the battery.

The generator will have a fairly linear rate that it puts electricity into the battery. If I was to speculate, in a use case of driving around town without towing, the generator will add electricity faster than you can used it. And if you’re doing something like highway towing you will use electricity faster than the generator is adding it.

There’s too many unknowns for any of us to know, but if I was going to guess, if you left with a full battery and tank of gas you’ll probably be able to go around 250 miles of towing on the highway with a reasonable load before you needed to stop to let the generator run (or connect to an EV charger).

 

[colinnwn]

"around 250 miles of towing on the highway with a reasonable load before you needed to stop to let the generator run (or connect to an EV charger)."

As much as I want a Scout to relive my youth driving one that I loved, that would probably be a deal breaker for me. I'd just keep my old Ford F150 I like fine enough, rather than dropping this significant coin. The Scout would actually be the first brand new car I've ever bought at close to 50 years old.

 

[Rouse]

"around 250 miles of towing on the highway with a reasonable load before you needed to stop to let the generator run (or connect to an EV charger)."

As much as I want a Scout to relive my youth driving one that I loved, that would probably be a deal breaker for me. I'd just keep my old Ford F150 I like fine enough, rather than dropping this significant coin. The Scout would actually be the first brand new car I've ever bought at close to 50 years old.

Yeah, I would guess if you wanted to do a full day (600+ miles) of highway towing, the most efficient way would be to stop for a short break every two hours or so, with one of those during the day being at a gas station to add fuel.

 

[Efthreeoh]

Things that are pretty well confirmed:
-the battery will have about 150 miles of range
-the gas tank and generator have the capacity to generate enough electricity to fill the battery around 2 1/3 times

Anyone that’s spent much time with an EV knows that use (speed, temperature, towing, braking, etc) can greatly influence the rate you’re using the charge in the battery.

The generator will have a fairly linear rate that it puts electricity into the battery. If I was to speculate, in a use case of driving around town without towing, the generator will add electricity faster than you can used it. And if you’re doing something like highway towing you will use electricity faster than the generator is adding it.

There’s too many unknowns for any of us to know, but if I was going to guess, if you left with a full battery and tank of gas you’ll probably be able to go around 250 miles of towing on the highway with a reasonable load before you needed to stop to let the generator run (or connect to an EV charger).

The way I see the range extender is a series hybrid similar to the GM Volt but without mechanical connection between the engine and the drive wheels through a (planetary) gearset. The Volt could drive entirely on the gas engine/generator and recharge the battery along with powering the electric drivetrain without performance loss.

The Volt could also be switched to EV mode without the engine starting or switched to gas mode. This is helpful if in the future, American cities being charging a carbon emissions tax for gas vehicles operating within city limits. Numerous European cities do this already, London is one such city.

I am hoping Scout makes the Harverster option a true series hybrid. IMO it is the ideal configuration for the American driving use case.

 

[ctuan13]

Here is my guess on how the Range Extender (RE) will work:

With RE Off
As long as you stay within the battery’s range or have access to charging… it’ll function like every other EV. For most days and for most drivers, this is the mode it’ll stay in for daily driving. You’ll get 3.5 miles avg per 1% battery drop.

With RE On; Battery at 35-100%
The battery will be supplemented by the generator with no output performance drop in the vehicle. The battery will simply be charging while being used… so battery % drops slower than without RE on. If turned on early in trip, you should have no drop in highway speeds for the whole 500 miles. You’ll get 5 miles avg for each 1% of battery drop.

With RE On; Battery below 35%
To prevent the battery from getting too low, performance of the vehicle will be throttled slightly to allow gas generator to slow the rate of battery depletion.

With RE On; Battery at 0% (or critically low)
Generator will charge battery at a rate that allows limited performance - approx. 42.9% max performance output. This is not ideal but would allow someone in a bad situation to limp along to find a charge or get home.

It is not my opinion that just by having gasoline you can drive infinitely with this vehicle. The gas has to have time to charge the battery. It is not more efficient than the battery - meaning a moving vehicle will always show battery loss - even with generator running. The vehicle would have to remain off to see battery charge upward.

Great breakdown. I just hope they do allow for vehicle stationary/off range extender charging. Meaning if you're gonna be camping or off-roading somewhere remote, but you have plenty of gas with you, you can recharge the battery while parked.