Speculation Alert - possible Harvester Engine Choices

[speedrye]

And we appreciate your patience.

Yes, details are limited for now as we want to set realistic expectations on range while we work towards production versions of the vehicles. While it will be 2+ years, we will have a LOT to talk about during development and testing. We are already building test mules, the factory is moving along nicely, our teams are constantly working through new and better solutions, battery tech incrementally improves, software continues to improve and evolve and so much more. While I'm sure having patience over the next two years will be tough at times, I think some of our original Scout Community forum contributors will tell you that the last two years went by surprisingly quick - and we didn't have any product to to talk about yet.

We are working on three different story/video programs right now: Rooted In Heritage, Driven By Community, and Forging The Future. These stories will tell a bit about Scout history, the Scout community, our road to production, and everything we're doing to bring the new Scout trucks to market.

So as soon as we can tell you all more details, we will. This forum will always be one of the first places to know.

It's okay, you can just admit you're crowd-sourcing ideas from us in an effort to keep engineering costs lower.

Just throw a vague statement out here and there, and let us do our thing!

 

[DBHowe]

I haven't given this much thought, but I would prefer the Scout to allow me to engage the Harvester manually (maybe that's the plan along with automatically?). My thinking is that I'm the one that knows if I'm spending the weekend running on trails with no access to a charging station in my campgrounds, or doing a 100 mile trip between charging stations. (edited. I just noticed that the range of the Harvester on battery only is about 150 miles. Less battery to leave room for the Harvester I would assume.)

In the back country I would run it something close to 100% of the time. Around home and major cities, I would keep it turned off. Maybe that's typically how systems like this are configured in other cars? The vast majority (80%+) of my driving would then be as an EV. I suppose there's a world where there will be charging stations in even the smallest of towns, but until then I really like this concept for a 4X4.

Also, in the 1994 earthquake in CA, power was out, and we were out of town and had to drive home. The Harvester would be a nice security blanket for blackouts where charging stations were unavailable.

 

[R1TVT]

On top is assumption, or hope that you could do this while towing. This seems unlikely given the size of engine. You will extend the range of the battery by blending in the RE, but it seems very unlikely you can tow once the battery is flat.

I think its pretty simple. If the motors are solely driven by electricity coming from the battery (as has been stated by Scout, and as it relates to Harvester), then NO - you will not be towing (or driving) anywhere with a flat battery. That is just not how a series hybrid works, and that is simply not possible from a simple mechanical and physics perspective.

In a series hybrid, there is no other way to turn a wheel without battery POWER and without an adequate SOC.

What you MIGHT be able to do with a "flat battery" is fill your gas tank for the Harvester, then sit idle while the RE runs and charges (sending XXXX amount of electrons into the battery pack). Then, once the battery pack has an adequate amount of electrons to propel the vehicle for XXXX amount of distance, you can drive away. Of course we will get details like this from Scout Motors over time, as stated by Jamie above.

 

[MountainDad]

Of course it will.

All the replies to me thinking I'm stupid and do not know what REEV is. But go check out i3 yourselves. If you have an underpowered engine that cannot even recharge your battery enough as you needed, the max power the battery out out would be equal (ideally) or less than what gas generator can put out. There's a reason RAM gives ramcharger the Penta v6. And it's why it's full battery performance is way higher, but when running on extender it's only the max power of the gas engine.

BMW made the choice they did because of vehicle classification rules - they have even stated that sizing the engine larger or giving it a larger tank would have tipped a balance toward range being provided under ICE power, and the vehicle would have been classified as a hybrid, driving additional changes to the gas engine for compliance. Both EPA and EU define a hybrid not by whether an ICE engines provides tractive motion, but by how much range one provides the vehicle vs. pure battery power. If an ICE engine is turning, it's emitting pollutants.

 

[MountainDad]

They are not the first in REEV. China has already had mature REEV products from various brands. Even ram uses technology from Chinese Leap Motors.

And diesel-electric locomotives and city buses have been using this technology for many decades.

The engineering and operational employment of series hybrid engines is well established.

 

[MountainDad]

Generator makes electricity. Battery gives electricity. Add the 2 together for more electricity than either can supply independently. No mechanical connection to drive line required.

You are asking to design a system that is both series electric and parallel electric, switchable between both. There's no free lunch, as we say in the systems engineering world.

This is difficult and expensive, because electricity in some ways is like water. If you have a high-pressure pipe and then want to add more water pressure by pushing more water in from a smaller low-pressure pipe, you have to consider and design against backflow into the low pressure pipe, because electricity, like water, is about energy flow from high potential to low potential. There are things called diodes that exist in the electrical world that don't exist in the water world, but they too have limitations and significant drawbacks.

It's much easier and cheaper to design the battery system sized such that it delivers all of the power you need to turn the wheels, and then size an engine to turn a generator sufficient to recharge when still or backfill the battery under load such that the net drain is slower. Then, all the water goes into one tank (the main battery), and you have one pump to push it out to the rest of the house at a rate that won't blow out your kitchen sprayer head, but also won't leave you unable to rinse the shampoo out of your eyes when the washing machine kicks on.

 

[MountainDad]

Zero chance they are going to use some weird experimental engine.

Also high power density is usually NOT a target for Generators. High power density = higher stress.

They will want something proven reliable, and running way below peak power, so it isn't stressed when run constantly at specified full load.

It's not a weird experimental engine - it's in use and on the market today.

For generators that sit outside a building or a home, you're correct - energy density isn't a concern. But when you're packaging into a vehicle, or an airplane, with NVH concerns and a desire to maximize things like cargo space, heat dissipation, etc, then it absolutely *is* a concern. You want as much power from as small a package as possible to turn a generator as quietly and efficiently as possible.

 

[dearbulls]

It's not a weird experimental engine - it's in use and on the market today.

For generators that sit outside a building or a home, you're correct - energy density isn't a concern. But when you're packaging into a vehicle, or an airplane, with NVH concerns and a desire to maximize things like cargo space, heat dissipation, etc, then it absolutely *is* a concern. You want as much power from as small a package as possible to turn a generator as quietly and efficiently as possible.

Correct. You need a balance between enough power and NVH/efficiency/packaging

 

[dearbulls]

BMW made the choice they did because of vehicle classification rules - they have even stated that sizing the engine larger or giving it a larger tank would have tipped a balance toward range being provided under ICE power, and the vehicle would have been classified as a hybrid, driving additional changes to the gas engine for compliance. Both EPA and EU define a hybrid not by whether an ICE engines provides tractive motion, but by how much range one provides the vehicle vs. pure battery power. If an ICE engine is turning, it's emitting pollutants.

We still do not know how big battery this pure BEV scout would be. Those 35s KO3 are not energy efficient at all.

2mi/kwh is what could be expected. 350mi without considering energy lost would need 175kwh battery. So 200kwh might be what's needed for BEV? Considering gas tank will take up some room, the Harvester should have at least 100kwh battery if not bigger. So it's why I think 100-130kw output from gas engine would be sufficient. And considering NVH and efficiency, it's why ram gave theirs a 3.6 v6 but only run it at 130-150kw I guess. But it should have the potential to rev higher and generate more in maybe acceleration or critical low SOC. But the scout packaging really didn't leave much room. Unless they can pack a GR Corolla's 3 cylinder that capable of 300hp.

 

[CarTechGeek]

I think its pretty simple. If the motors are solely driven by electricity coming from the battery (as has been stated by Scout, and as it relates to Harvester), then NO - you will not be towing (or driving) anywhere with a flat battery. That is just not how a series hybrid works, and that is simply not possible from a simple mechanical and physics perspective.

I think you misinterpreted what was said.

With the Harvester in use, Most, if not all of the power will be coming from the generator.

In a series hybrid, there is no other way to turn a wheel without battery POWER and without an adequate SOC.

A small buffer will need to be maintained, but in all series hybrids: Most if, not all of the power is coming from the Generator.

The new Honda Hybrids are essentially series Hybrid (except at highway speed) with a Tiny ~1KWh battery, so they are obviously getting essentially all their power from the generator. That is just how Series Hybrids work.

Nissan E-Power Hybrids are exclusively Series Hybrids with again a Tiny ~1KWh battery, so again, all the power has to come from the generator.

 

[R1TVT]

I think you misinterpreted what was said.

How so? I was confirming what you wrote, which was " it seems very unlikely you can tow once the battery is flat."

Once the battery is flat, you aren't towing or moving anywhere - the electric motors being supplied with energy from the battery are not turning.

 

[CarTechGeek]

How so? I was confirming what you wrote, which was " it seems very unlikely you can tow once the battery is flat."

Once the battery is flat, you aren't towing or moving anywhere - the electric motors being supplied with energy from the battery are not turning.

You said "(or driving) anywhere"

You further claimed: "solely driven by electricity coming from the battery"

Both are just wrong. Also when I said you aren't towing with a flat battery. I meant in a practical sense. You can still tow at maybe 10 miles/hour. It's simply about how much power it takes to tow at speed vs how much your generator can produce. The Ramcharger with 130 KW genset will be able to tow some loads with a flat battery.

Series hybrids when running in range extender mode will get all or most of their power from the generator. It's just how they work.

 

[Chaparral]

I haven't really seen much confusing it with a traditional hybrid. Just different expectations on the power output of the Range extender, and it expected capability.

At the lowest level, is something that can barely run highway speed on it's own (like BMW i3 Rex), or even lower, such that you need a constant draw from the battery to run highway speed. This would make many less happy.

In the middle is an assumption that you can run indefinitely on RE output at highway speeds. This probably the sweet spot of possibility, given the size of engine that will fit.

On top is assumption, or hope that you could do this while towing. This seems unlikely given the size of engine. You will extend the range of the battery by blending in the RE, but it seems very unlikely you can tow once the battery is flat.

I think we just need to follow all the data points and statements that Scout have given us, rather than project our own wishes.

1) Full sized battery version has estimated range of 350 miles
2) For the Harvester version they “make the battery a little bit smaller, fill that space with a gas tank”.
3) Scout’s marketing images show the battery is almost full size and the gas tank is small.
4) The images show the Harvester engine is tucked below the floor of the rear cargo area, perhaps making the cargo space just a little smaller. They show something more the size of a motorbike engine than a truck engine.
5) Full range with the Harvester is about 500 miles. (probably with the Harvester running the entire journey)
6) The Harvester version normally runs as a pure EV for about 150 miles. (this doesn’t necessarily mean the battery is flat after 150 miles, more likely it has reached a certain percentage where the Harvester is set to kick in)
7) According to the website, with the Harvester you can “go the extra mile, and then go a couple hundred more”. (this is ambiguous, but since the Harvester is only estimated to go 150 miles more than the BEV it must be talking about something else, it might be a clue or it might not.)
8) Scout’s marketing video introduces it as “EV Power and Tech with a bit of gas” (“bit of” suggests a small contribution)
9) The Harvester charges the battery

Putting all this together, I don’t think Scout are setting expectations for a big gas engine. The Harvester output only extends the life of the battery, so it can go further before needing to be re-charged. There’s no reason to expect the Harvester to indefinitely maintain the battery’s state of charge during normal driving, which would require a large engine that would take up a lot of space. They literally showed us images of something very small. Just believe your own eyes. It is small.

I’m expecting the Harvester to provide energy for about 200 miles of the 500 mile trip, a gas tank that’s 10 gallons or less, a battery that’s about 15% smaller and an engine that’s about 750cc.

Because it only charges the battery, the little engine will probably run at a constant speed that provides optimal efficiency. It can be small because it does not need to provide bursts of high output like an engine driving a transmission does.

 

[Chaparral]

Series hybrids when running in range extender mode will get all or most of their power from the generator. It's just how they work.

They don’t have to work that way and it is impossible based on what Scout showed us - a picture of a tiny little engine under the floor of the rear storage space/truck bed. Nothing that small can provide “all or most” of the driving power. Vehicles that do, have a full sized engine in an engine bay. That’s not what Scout are doing.

 

[CarTechGeek]

I think we just need to follow all the data points and statements that Scout have given us, rather than project our own wishes.

1) Full sized battery version has estimated range of 350 miles
2) For the Harvester version they “make the battery a little bit smaller, fill that space with a gas tank”.

I think it will be a little bit smaller than the Base battery, not the optional 350 mile battery.

 

[CarTechGeek]

They don’t have to work that way and it is impossible based on what Scout showed us - a picture of a tiny little engine under the floor of the rear storage space/truck bed. Nothing that small can provide “all or most” of the driving power. Vehicles that do, have a full sized engine in an engine bay. That’s not what Scout are doing.

They don't have to work that way, but that is how every Series Hybrid in existence has worked.

A 1.5L Naturally aspirated Engine can demonstrably generate 55 KW power in that application. See Chevy Bolt.

So a 3 Cyl 1.5L engine could do the job, and IMO, with some tilt could fit back there.
That was exactly my answer to what engine they should use:

https://scoutmotors.community.forum/threads/speculation-alert-possible-harvester-engine-choices.1085/page-4#post-11611

55KW is more than adequate to drive an F150 Lightning at 70 MPH down the highway.

 

[Noplacelikeloam]

I think it will be a little bit smaller than the Base battery, not the optional 350 mile battery.

My money is on a 200 mile range battery. Assume base battery is 250. Less than that and it will be a problem in 2027. If a Mini BEV can get that range today, a 2027 truck should be able to also, RE or not.

 

[Chaparral]

I think it will be a little bit smaller than the Base battery, not the optional 350 mile battery.

That’s what they said

and what I said.

Specifically I estimated 15% smaller, they are just making room for a gas tank, 10 gallons of which should be more than enough.

 

[CarTechGeek]

Generator makes electricity. Battery gives electricity. Add the 2 together for more electricity than either can supply independently. No mechanical connection to drive line required.

Contrary to what others have replied, you are correct, it would be relatively easy to boost power when running the gas engine to boost beyond the power output of the battery alone. You already have to be able to blend power from both system, so getting them to go beyond what the battery already provides is almost trivial.

That is precisely how the Fisker Karma, the very first plug-in series hybrid/EREV sold in the USA, operated.

0-60 in Battery only mode was about 8 seconds.
0-60 with Range extender running to boost power was about 6 seconds. Significantly faster.

The only question, is if they will want to do this, because they aren't making a sports car. Coin toss on that one.

 

[CarTechGeek]

It's not a weird experimental engine - it's in use and on the market today.

What commercial product can I buy, with that engine in it?

If I can't buy a commercial product, with that engine, then it's still in the experimental stage.

It was basically only revealed as a prototype last year:

Zero Cranks Given: Is The INNengine Feasible Or Just Pure Folly?

A firm called INNengine built an engine that doesn't have valves or a crankshaft, and after slapping it into a Miata they took it for a spin.

www.enginelabs.com

And already they were caught making misleading claims about not having a Turbo, and running at atmospheric pressure. Internet Engine analyst D4A, pointed out the supercharger that they had attached:

Questions about their claims, and especially durability will take many more years to answer.