Traveler Engine Sizing

[DBHowe]

I looked (kind of quickly) for this discussion and couldn't find it (it must be here somewhere).

Regarding the generation capacity of the Traveler, it would be best for me if it would be capable of generating enough power for the Scout to go 65-70 miles an hour without assistance from the batteries. In other words, a stop at a gas station would allow me to keep going until I needed to stop for gas again. Now hear me out... I know this seems like I just want an ICE, but here's my thinking.

80% of my driving is around town. All of these miles would be 100% on the batteries. But if I take off across the country it might be more convenient for me to get a tank of gas.

Seems like the best of both worlds for me. Around town I get crazy fuel economy always running EV. When and if I need to, I run on the Traveler and realize that I may only get 25 miles per gallon of gas, but I make the decision whether I want to do that or hit a charging station. I realize that this requires a larger Traveler engine and that adds weight and takes up more space, as does a larger gas tank. To reduce the engine size, I would be happy to trade off performance. Slower acceleration, lower top speed, no towing, etc. when running off of the Traveler engine.

So around town it functions as an EV, but is has the ability to function as a "modern train locomotive" when that's best for me. Is this what Scout Motors has in mind for the Traveler? Or when you get to the maximum stated mileage, and you are out of battery and out of gas, the Scout must visit a charging station?

If this topic is covered somewhere else, please let me know where and I'll pull this post down. I don't want to drag through a topic that has already been well discussed. Thanks. I'm still working to get my brain up-to-speed on EVs.

 

[Bodie]

I want what you want. This thread contains a lot of that if you want a painful read:

https://scoutmotors.community.forum/threads/speculation-alert-possible-harvester-engine-choices.1085/

 

[R1TVT]

Yes. It has been covered, but there is no definitive / defined architecture or specs, so we don't know exactly what production will look like.

There is a DEFINED RANGE target. If you top off your battery and have a 100% SOC and a full tank for the Harvester, you should theoretically be able to travel ~500 miles. Of course the exact distance will vary based on a ton of variables, but you should be able to get close the range max.

Someone here can correct me if I am wrong, but we don't yet know what happens when you reach your 500 mile range limit...

FWIW, my expectation would be that you would want to charge and top of your Harvester tank if both systems were depleted, but you will more likely want to do these things separately (at different intervals perhaps) to maximize efficiency and reduce the amount of time spent at a gas station or a charger - meaning you really wouldn't want to run your systems down to SAFE MODE to effectively charge and fuel up on a multi-leg longer distance trip. This is not really different than traveling in an EV, where you typically charge within the faster parts of your charging curve and never stop to charge to 100% on a road trip, unless it is perhaps your last stop before reaching a destination where you need the extra buffer.

Once you reach your range limit and you hit ZERO in the Scout (which you should never do) or get to a critically low SOC and have no gas, the vehicle would (theoretically) operate in a controlled safe-mode for some undefined amount of time/distance to get you to a safe place to charge/fuel up. We don't yet know when SAFE MODE will be triggered or what that buffer will be.

Depending upon the implementation, yes, you could (theoretically) gas up and go some undefined amount of distance further on the Harvester immediately in ICE-ONLY mode (if that is a thing), but only if the Harvester were designed as you have suggested and the Harvester had a direct connection to the drivetrain motors and sent energy directly to an inverter ahead of the motors to propel the LARGE, HEAVY & BOXY truck forward. What you are suggesting is essentially what RAMCHARGER is trying to do with a full-sized V6, whereby the generator could be used to power the battery pack OR add power to the motors directly. BUT the Scout will not have a full sized V6. it will have a frunk!

There is a debate that Scout's 2 systems will operate differently since it will have to house a smaller generator used to "extend" range and send energy to the battery pack, so the truck operates as a true EV. In this case, and when you reach a low SOC and hit SAFE MODE, you could (theoretically) fill the Harvester tank, enable native power generation and then wait for the Harvester to charge the battery (to some undefined SOC). That would then allow you to travel some undefined amount of distance further on the battery, with the Harvester (theoretically) also running in the background to help preserve SOC and slow the discharge of electrons from the battery. How much time it would take to charge can be theorized and how much distance you would get based on the amount of time the Harvester runs, can also be theorized, but this is all speculation at this stage.

Since the details, specs and implementation are TBD, and since SCOUT is giving you a frunk (and not just dropping a 3.6L Pentastar V6 into the frunk), it will be interesting to see how Scout delivers on the Harvester configuration.

For reference, this is how RAM defines its system on its website, but even these details are all a little vague. They seem to have done this to address the power requirements for longer distance towing as a primary design driver:

"The All-New 2025 Ramcharger delivers innovative performance with a liquid-cooled 92-kilowatt-hour battery pack paired with a 130-kilowatt generator. The 3.6L Pentastar® V6 engine generates mechanical power, which is converted to electrical power by the onboard generator for maximum efficiency. The generator can also increase the power to the motor and gearbox when serious power is needed."

 

[J Alynn]

Yes. It has been covered, but there is no definitive / defined architecture or specs, so we don't know exactly what production will look like.

There is a DEFINED RANGE target. If you top off your battery and have a 100% SOC and a full tank for the Harvester, you should theoretically be able to travel ~500 miles. Of course the exact distance will vary based on a ton of variables, but you should be able to get close the range max.

Someone here can correct me if I am wrong, but we don't yet know what happens when you reach your 500 mile range limit...

FWIW, my expectation would be that you would want to charge and top of your Harvester tank if both systems were depleted, but you will more likely want to do these things separately (at different intervals perhaps) to maximize efficiency and reduce the amount of time spent at a gas station or a charger - meaning you really wouldn't want to run your systems down to SAFE MODE to effectively charge and fuel up on a multi-leg longer distance trip. This is not really different than traveling in an EV, where you typically charge within the faster parts of your charging curve and never stop to charge to 100% on a road trip, unless it is perhaps your last stop before reaching a destination where you need the extra buffer.

Once you reach your range limit and you hit ZERO in the Scout (which you should never do) or get to a critically low SOC and have no gas, the vehicle would (theoretically) operate in a controlled safe-mode for some undefined amount of time/distance to get you to a safe place to charge/fuel up. We don't yet know when SAFE MODE will be triggered or what that buffer will be.

Depending upon the implementation, yes, you could (theoretically) gas up and go some undefined amount of distance further on the Harvester immediately in ICE-ONLY mode (if that is a thing), but only if the Harvester were designed as you have suggested and the Harvester had a direct connection to the drivetrain motors and sent energy directly to an inverter ahead of the motors to propel the LARGE, HEAVY & BOXY truck forward. What you are suggesting is essentially what RAMCHARGER is trying to do with a full-sized V6, whereby the generator could be used to power the battery pack OR add power to the motors directly. BUT the Scout will not have a full sized V6. it will have a frunk!

There is a debate that Scout's 2 systems will operate differently since it will have to house a smaller generator used to "extend" range and send energy to the battery pack, so the truck operates as a true EV. In this case, and when you reach a low SOC and hit SAFE MODE, you could (theoretically) fill the Harvester tank, enable native power generation and then wait for the Harvester to charge the battery (to some undefined SOC). That would then allow you to travel some undefined amount of distance further on the battery, with the Harvester (theoretically) also running in the background to help preserve SOC and slow the discharge of electrons from the battery. How much time it would take to charge can be theorized and how much distance you would get based on the amount of time the Harvester runs, can also be theorized, but this is all speculation at this stage.

Since the details, specs and implementation are TBD, and since SCOUT is giving you a frunk (and not just dropping a 3.6L Pentastar V6 into the frunk), it will be interesting to see how Scout delivers on the Harvester configuration.

For reference, this is how RAM defines its system on its website, but even these details are all a little vague. They seem to have done this to address the power requirements for longer distance towing as a primary design driver:

"The All-New 2025 Ramcharger delivers innovative performance with a liquid-cooled 92-kilowatt-hour battery pack paired with a 130-kilowatt generator. The 3.6L Pentastar® V6 engine generates mechanical power, which is converted to electrical power by the onboard generator for maximum efficiency. The generator can also increase the power to the motor and gearbox when serious power is needed."

DAMN M-
Your fingers must be tired from typing that thesis ?
This was a GREAT recap-thanks for sharing

 

[Logan]

Yep, there is a lot that we don’t know yet. It will be very interesting to see how the harvester is implemented.

For what it’s worth, here is a bit more data on how the Ramcharger is apparently going to be setup. It’s interesting because it adds some color to the discussion, even if it’s for a competing vehicle (and I’m not saying the scouts will be designed this way, but still a good read).

First, the design intent of the Ramcharger is totally to tow. I don’t have a link handy, but I’ve read that while doing EV truck product testing, they went for a drive with a loaded trailer, and didn’t even reach their first stop without needing to charge. They looked at each other and said “we’ve got to do something different” (or something to that effect).

Also, the Ramcharger is set with a higher tow rating than the Terra/Traveler. It’s designed around a 14k lb tow rating. That’s a solid 40% more than the Terra, and almost 100% more than the Traveler. So even with similar design intentions, I’d think the engine size/output would/could be proportionally smaller.

Those 145 miles of battery range will likely drop to less than half that when towing, but the generator keeps the rig rolling after that. The generator in question is rated at 174 horsepower of continuous output. That doesn't sound like any way to keep up while towing 14,000 pounds, but a Ram powertrain engineer we spoke to says this is plenty. On generator power, you can cruise a flat interstate at 65 mph with a max load trailer until the fuel tank needs to be refilled. Tow something like 7000 pounds, and it only gets better.

Also, the same article seems to specify the state of charge that the generator kicks on, which is not seen before.

Headed for the mountains? Select Tow mode, and the charge-sustaining set-aside percentage is increased to 35 percent, up from the normal 16 percent. The V-6 engine and generator set will come online earlier, and the generator will run closer to peak output more of the time. Between that and the enlarged Tow mode battery reserve, Ram says the Ramcharger should be more than able to tackle the kind of long, steep grades found in the mountain West.

Interestingly, if you reduce the power output of Ramchargers generator by 40%, (to match the reduction in tow rating) you get a very similar output to some of the theories floating around.

174hp constant output X 0.6 == 105hp.

Here is the rest of the article I’ve quoted above. Was interesting.

https://www.caranddriver.com/news/a45758306/2025-ram-1500-ramcharger-towing/

Personally, I think something closer to gas/go functionality is what they’re targeting (at least when unladen). But if they go the other way, I imagine that like you, I’d likely separate the fuel/charging stops.

I think we’re all quite interested in seeing what they cook up for us .

 

[Wings]

Is the engine planned to have regular or premium gas?