Deep Dive into EREV - Ramcharger vs Harvester?

[Cranky Canuck]

Alex on Autos just did a great deep dive into the new Ramcharger and how it will work complete with numbers.

I know we haven't received any detailed numbers from Scout on the Harvester drivetrain but we all live under the same laws of physics and the state of the technology is what it is so everyone is operating under the same basic constraints. We should therefore be able to make some pretty educated guesses based on the numbers and specs of the Ramcharger and what Scout has said so far.

When I was mentally comparing the two vehicles while Alex talked about the Ramcharger, a few points came to my mind:

• Ram is using NCM whereas Scout will use LFP for this application

I think that's a win for Scout. LFP is a much better chemistry for the kinds of duty cycles we can expect an EREV to endure. So good job Scout on picking the better battery chemistry there.

• Ramcharger will have a 92kWh battery with ~70kWh usable giving 145 miles of range.

This has be a little concerned about the released specs so far with the Scout. Ram is reserving more than 20% of the battery pack for battery health (top 3% and bottom 7%) and as a buffer for when the engine is running (~10%), it also reserves more if towing. That is a huge battery, bigger than I think what Scout has been hinting at, so I'm concerned that Scout might not meet its range targets. Speaking of engines though;

• The gas generator in the Ram (V6 Pentastar) will produce 202 kW peak and 130 kW sustained. Those are huge numbers.

To put that into context most DC fast chargers run at between 50kW and 150kW so having an engine producing what a DC fast charger basically can do means it will very likely be fine running down the highway with a low battery charge (unlike the BMW i3). But it makes me question how beefy the Harvester will be. I don't think they've talked much about how many kW it will be able to produce but I don't think it's anywhere near these numbers so again, I have concerns.

• Ramcharger will be a 350V vehicle.

This is a miss by Ram for sure. Scout has it right with 800V. The Ram will take over an hour to charge from 10% to 80% which is insane in 2025 let alone in 2028 when the Scout will show up in quantity. Scout got it very right here and Ram will be kicking themselves (hopefully) with this mistake. It will make the Ramcharger painful to try and fast charger and I predict most owners will just buy gas and charge at home if they remember to. They'll never bother with hitting up a level 3 charger (why would they, it'll take forever!).

• Both vehicles are serial hybrids so they're essentially the same basic architecture that diesel rail locomotives have been using for a century now. So that's cool.

One question I do have that hopefully @Jamie@ScoutMotors might be able to answer is; will the Scout EREV and EVs have a front-motor disconnect?

Front motor disconnect is a huge efficiency advantage when doing long highway drives. If you aren't powering an electric motor it still creates drag on the drivetrain just by having it 'free wheeling' so it's better to completely disconnect it via a clutch. My Ioniq 5 has that and all AWD E-GMP platform cars do (Hyundais & Kias) because it makes a big difference. You don't always need all wheel drive, especially on long highway trips where rear wheel drive is plenty so it makes sens to have the front motor physically disconnect to reduce drag. Tesla gets around this in their AWDs with a front induction motor which is also a neat solution but has it's own disadvantages as well. Assuming the front motor will be the cheaper permanent magnet motors that we expect it would make sense to have a clutch to take out the drag when it's not being used.

Anyway here's the video if you're interested in how Ram is doing their EREV.

 

[THil08]

Alex on Autos just did a great deep dive into the new Ramcharger and how it will work complete with numbers.

I know we haven't received any detailed numbers from Scout on the Harvester drivetrain but we all live under the same laws of physics and the state of the technology is what it is so everyone is operating under the same basic constraints. We should therefore be able to make some pretty educated guesses based on the numbers and specs of the Ramcharger and what Scout has said so far.

When I was mentally comparing the two vehicles while Alex talked about the Ramcharger, a few points came to my mind:

• Ram is using NCM whereas Scout will use LFP for this application

I think that's a win for Scout. LFP is a much better chemistry for the kinds of duty cycles we can expect an EREV to endure. So good job Scout on picking the better battery chemistry there.

• Ramcharger will have a 92kWh battery with ~70kWh usable giving 145 miles of range.

This has be a little concerned about the released specs so far with the Scout. Ram is reserving more than 20% of the battery pack for battery health (top 3% and bottom 7%) and as a buffer for when the engine is running (~10%), it also reserves more if towing. That is a huge battery, bigger than I think what Scout has been hinting at, so I'm concerned that Scout might not meet its range targets. Speaking of engines though;

• The gas generator in the Ram (V6 Pentastar) will produce 202 kW peak and 130 kW sustained. Those are huge numbers.

To put that into context most DC fast chargers run at between 50kW and 150kW so having an engine producing what a DC fast charger basically can do means it will very likely be fine running down the highway with a low battery charge (unlike the BMW i3). But it makes me question how beefy the Harvester will be. I don't think they've talked much about how many kW it will be able to produce but I don't think it's anywhere near these numbers so again, I have concerns.

• Ramcharger will be a 350V vehicle.

This is a miss by Ram for sure. Scout has it right with 800V. The Ram will take over an hour to charge from 10% to 80% which is insane in 2025 let alone in 2028 when the Scout will show up in quantity. Scout got it very right here and Ram will be kicking themselves (hopefully) with this mistake. It will make the Ramcharger painful to try and fast charger and I predict most owners will just buy gas and charge at home if they remember to. They'll never bother with hitting up a level 3 charger (why would they, it'll take forever!).

• Both vehicles are serial hybrids so they're essentially the same basic architecture that diesel rail locomotives have been using for a century now. So that's cool.

One question I do have that hopefully @Jamie@ScoutMotors might be able to answer is; will the Scout EREV and EVs have a front-motor disconnect?

Front motor disconnect is a huge efficiency advantage when doing long highway drives. If you aren't powering an electric motor it still creates drag on the drivetrain just by having it 'free wheeling' so it's better to completely disconnect it via a clutch. My Ioniq 5 has that and all AWD E-GMP platform cars do (Hyundais & Kias) because it makes a big difference. You don't always need all wheel drive, especially on long highway trips where rear wheel drive is plenty so it makes sens to have the front motor physically disconnect to reduce drag. Tesla gets around this in their AWDs with a front induction motor which is also a neat solution but has it's own disadvantages as well. Assuming the front motor will be the cheaper permanent magnet motors that we expect it would make sense to have a clutch to take out the drag when it's not being used.

Anyway here's the video if you're interested in how Ram is doing their EREV.

I agree with all your points and comments about the concerns for the Harvester. Would definitely like some answers on it.

 

[J Alynn]

Alex on Autos just did a great deep dive into the new Ramcharger and how it will work complete with numbers.

I know we haven't received any detailed numbers from Scout on the Harvester drivetrain but we all live under the same laws of physics and the state of the technology is what it is so everyone is operating under the same basic constraints. We should therefore be able to make some pretty educated guesses based on the numbers and specs of the Ramcharger and what Scout has said so far.

When I was mentally comparing the two vehicles while Alex talked about the Ramcharger, a few points came to my mind:

• Ram is using NCM whereas Scout will use LFP for this application

I think that's a win for Scout. LFP is a much better chemistry for the kinds of duty cycles we can expect an EREV to endure. So good job Scout on picking the better battery chemistry there.

• Ramcharger will have a 92kWh battery with ~70kWh usable giving 145 miles of range.

This has be a little concerned about the released specs so far with the Scout. Ram is reserving more than 20% of the battery pack for battery health (top 3% and bottom 7%) and as a buffer for when the engine is running (~10%), it also reserves more if towing. That is a huge battery, bigger than I think what Scout has been hinting at, so I'm concerned that Scout might not meet its range targets. Speaking of engines though;

• The gas generator in the Ram (V6 Pentastar) will produce 202 kW peak and 130 kW sustained. Those are huge numbers.

To put that into context most DC fast chargers run at between 50kW and 150kW so having an engine producing what a DC fast charger basically can do means it will very likely be fine running down the highway with a low battery charge (unlike the BMW i3). But it makes me question how beefy the Harvester will be. I don't think they've talked much about how many kW it will be able to produce but I don't think it's anywhere near these numbers so again, I have concerns.

• Ramcharger will be a 350V vehicle.

This is a miss by Ram for sure. Scout has it right with 800V. The Ram will take over an hour to charge from 10% to 80% which is insane in 2025 let alone in 2028 when the Scout will show up in quantity. Scout got it very right here and Ram will be kicking themselves (hopefully) with this mistake. It will make the Ramcharger painful to try and fast charger and I predict most owners will just buy gas and charge at home if they remember to. They'll never bother with hitting up a level 3 charger (why would they, it'll take forever!).

• Both vehicles are serial hybrids so they're essentially the same basic architecture that diesel rail locomotives have been using for a century now. So that's cool.

One question I do have that hopefully @Jamie@ScoutMotors might be able to answer is; will the Scout EREV and EVs have a front-motor disconnect?

Front motor disconnect is a huge efficiency advantage when doing long highway drives. If you aren't powering an electric motor it still creates drag on the drivetrain just by having it 'free wheeling' so it's better to completely disconnect it via a clutch. My Ioniq 5 has that and all AWD E-GMP platform cars do (Hyundais & Kias) because it makes a big difference. You don't always need all wheel drive, especially on long highway trips where rear wheel drive is plenty so it makes sens to have the front motor physically disconnect to reduce drag. Tesla gets around this in their AWDs with a front induction motor which is also a neat solution but has it's own disadvantages as well. Assuming the front motor will be the cheaper permanent magnet motors that we expect it would make sense to have a clutch to take out the drag when it's not being used.

Anyway here's the video if you're interested in how Ram is doing their EREV.

Thanks for your educated breakdown on this

 

[CarTechGeek]

This has be a little concerned about the released specs so far with the Scout. Ram is reserving more than 20% of the battery pack for battery health (top 3% and bottom 7%) and as a buffer for when the engine is running (~10%), it also reserves more if towing. That is a huge battery, bigger than I think what Scout has been hinting at, so I'm concerned that Scout might not meet its range targets. Speaking of engines though;

Using LFP means Harvester they can get away with a bit less reserve capacity. I don't think we know details like if Scout battery size was usable or total capacity yet...

But it makes me question how beefy the Harvester will be. I don't think they've talked much about how many kW it will be able to produce but I don't think it's anywhere near these numbers so again, I have concerns.

I think Harvester will be capable of normal highway travel in charge sustaining mode. I think that was essentially mentioned in Jay Leno discussion or elsewhere, but it will undoubtedly have significantly less extra headroom to handle tougher loads, like the Ramcharger.

• Ramcharger will be a 350V vehicle.

This is a miss by Ram for sure. Scout has it right with 800V. The Ram will take over an hour to charge from 10% to 80% which is insane in 2025 let alone in 2028 when the Scout will show up in quantity.

Numbers I read/heard are 50 Miles of range back in 10 minutes, and 45 minutes to 80%.

It would be an issue for a BEV, but IMO, it's largely a non issue for PHEV, which you will mostly just "charge" with gasoline when away from home. Most PHEVs don't have any DC fast charging capability at all. Just L2 AC charging.

 

[Mousehunter]

The real question will be how much the Harvester will produce. I did some quick calculations - it could be as low as 28kw/h, which would be about what is necessary for Steady State at 70mph (they have said the design goal was steady state at 70mph, and I am assuming that the range of the EV is also at 70mph).

Ultimately it will depend on the compromises Scout makes. The Ram is designed to tow - so they need enough power not only to drive at a steady state with a towing load, but to accelerate good at that load-can not really expect regen brakes to work the same way with a trailer, unless you want it coming around (trailers need brakes too). They will sacrifice mileage when used as an ICE when not towing, and they will sacrifice sticker price - it will be significantly more expensive to make with the larger engine. Scout seems to be focusing on every day efficiency. They want to hit a price point, they want a 500 mile combined range. They recognize that the Scout is not going to be towing 15k lbs cross country. While nothing is set in stone - Scouts design goal will come at the expense of towing ability (but probably not the towing capacity for their target market, it will still fit for the vast majority of their market - people who seriously tow will be getting a different vehicle.

 

[Dana]

The real question will be how much the Harvester will produce. I did some quick calculations - it could be as low as 28kw/h, which would be about what is necessary for Steady State at 70mph (they have said the design goal was steady state at 70mph, and I am assuming that the range of the EV is also at 70mph).

Ultimately it will depend on the compromises Scout makes. The Ram is designed to tow - so they need enough power not only to drive at a steady state with a towing load, but to accelerate good at that load-can not really expect regen brakes to work the same way with a trailer, unless you want it coming around (trailers need brakes too). They will sacrifice mileage when used as an ICE when not towing, and they will sacrifice sticker price - it will be significantly more expensive to make with the larger engine. Scout seems to be focusing on every day efficiency. They want to hit a price point, they want a 500 mile combined range. They recognize that the Scout is not going to be towing 15k lbs cross country. While nothing is set in stone - Scouts design goal will come at the expense of towing ability (but probably not the towing capacity for their target market, it will still fit for the vast majority of their market - people who seriously tow will be getting a different vehicle.

Agree. Range is everything. No one regrets having more range. I’ve thought it a major mistake by Ford to have such small batteries in the Mach E and Lightning. Size matters. I’d love Harvester to have a 350m battery plus Harvester range. I’d happily give up the frunk.

 

[THil08]

The real question will be how much the Harvester will produce. I did some quick calculations - it could be as low as 28kw/h, which would be about what is necessary for Steady State at 70mph (they have said the design goal was steady state at 70mph, and I am assuming that the range of the EV is also at 70mph).

Ultimately it will depend on the compromises Scout makes. The Ram is designed to tow - so they need enough power not only to drive at a steady state with a towing load, but to accelerate good at that load-can not really expect regen brakes to work the same way with a trailer, unless you want it coming around (trailers need brakes too). They will sacrifice mileage when used as an ICE when not towing, and they will sacrifice sticker price - it will be significantly more expensive to make with the larger engine. Scout seems to be focusing on every day efficiency. They want to hit a price point, they want a 500 mile combined range. They recognize that the Scout is not going to be towing 15k lbs cross country. While nothing is set in stone - Scouts design goal will come at the expense of towing ability (but probably not the towing capacity for their target market, it will still fit for the vast majority of their market - people who seriously tow will be getting a different vehicle.

70mph steady state? Scout definitely did do enough research on NJ. 80+ mph is NJ steady state of speed. That number better go up a bit.

Is the 70mph steady state referring to towing with the Harvester? @Jamie@ScoutMotors

 

[DaveGunter]

This diagram indicates what some of us have been saying...that the generator supplies electricity directly to the drive motors, so it doesn't just "recharge the battery"

 

[CarTechGeek]

This diagram indicates what some of us have been saying...that the generator supplies electricity directly to the drive motors, so it doesn't just "recharge the battery"
View attachment 5350

That's for the Ramcharger though. People claiming it will only charge the batteries were claiming that for the Harvester. Based on the simplified marketing that Scout is presenting.

But yes, the Harvester will work like this as well. They all do.

It's nearly impossible to "only charge the batteries", unless you drive until your run down the batteries, and then park it while it "charges the batteries". It's just an unfortunate marketing simplification that Scout is using, that some people are taking literally.

 

[J Alynn]

That's for the Ramcharger though. People claiming it will only charge the batteries were claiming that for the Harvester. Based on the simplified marketing that Scout is presenting.

But yes, the Harvester will work like this as well. They all do.

It's nearly impossible to "only charge the batteries", unless you drive until your run down the batteries, and then park it while it "charges the batteries". It's just an unfortunate marketing simplification that Scout is using, that some people are taking literally.

That has never been stated so it’s hard to just assume that. To date, every time Scott talks about it the generator charges the battery. Until they give final distinctions I will wait to see what is legit and what isn’t.

 

[Mousehunter]

I guess it is semantics. This is a completely electric power train. If charge is fed to the battery at the same time that a load is applied - then sure, the charge is effectively bypassing the battery and directly connected to the motor controller. But I still think it is easier to think of this as a generator charging the battery, and the question is weather or not the charge exceeds the load at any given point in time. The Ram is being designed so that is normally the case. The Scout appears to be designed with a more balanced and economical approach - targeting steady state under normal usage as opposed to targeting steady state under all but the most extreme maximum load (hard acceleration at max towing capacity).

 

[CarTechGeek]

That has never been stated so it’s hard to just assume that. To date, every time Scott talks about it the generator charges the battery. Until they give final distinctions I will wait to see what is legit and what isn’t.

It isn't hard to assume that at all. It's essentially a requirement that generator must be able to send power directly to the motors directly. It's just how series hybrids work, and must work to be practical.

It's only unfortunate marketing speak that is convincing people otherwise.

 

[CarTechGeek]

I guess it is semantics. This is a completely electric power train. If charge is fed to the battery at the same time that a load is applied - then sure, the charge is effectively bypassing the battery and directly connected to the motor controller.

That's not how it works. There is nothing incidental about this. They aren't passively connected to each other with overflow going to the motor. They aren't even the same type of power the motor uses AC vs the batteries are DC.

The battery is not the central component. The inverter is. All power flows go through the inverter.

Generator output (AC) will be fed into the inverter where it will be conditioned and portioned out. Computers deciding exactly how much power goes to the battery for charging ( 0-100% as DC voltage) and how much goes to the motor (0-100% as AC Voltage).

In cases of high demand 100% will go to the wheel motors, and additional will be added from the batteries. Obviously NOT possible while the batteries are charging only.

 

[Logan]

Using LFP means Harvester they can get away with a bit less reserve capacity. I don't think we know details like if Scout battery size was usable or total capacity yet...

I was going to mention this. The Ramcharger being NMC means it needs to keep more buffer, for battery health. LFP batteries handle charging to 100% often, better. And TBH, I'm sort of surprised that the Ramchargers 92KWh was gross, but then the useable turned out to be much closer to what Scout is saying their battery packs will be.

But AFAIK, we don't know what if the ~60-70kwh is gross, or useable.

Either way, with both of these getting ~140-150 miles of EV range out of them from ~60-70KWh, that means they're more efficient than we initially assumed, which is great news.

 

[J Alynn]

That's not how it works. There is nothing incidental about this. They aren't passively connected to each other with overflow going to the motor. They aren't even the same type of power the motor uses AC vs the batteries are DC.

The battery is not the central component. The inverter is. All power flows go through the inverter.

Generator output (AC) will be fed into the inverter where it will be conditioned and portioned out. Computers deciding exactly how much power goes to the battery for charging ( 0-100% as DC voltage) and how much goes to the motor (0-100% as AC Voltage).

In cases of high demand 100% will go to the wheel motors, and additional will be added from the batteries. Obviously NOT possible while the batteries are charging only.

Out of curiosity-are you on the engineering team? You seem to know a lot more than what is being said and commented on

 

[THil08]

Out of curiosity-are you on the engineering team? You seem to know a lot more than what is being said and commented on

I couldn’t agree with you more on that.

 

[CarTechGeek]

Out of curiosity-are you on the engineering team? You seem to know a lot more than what is being said and commented on

You don't have to be on the engineering team to know they aren't going to do something regressive and impractical.

It's an unfortunate marketing simplification, that has them emphasize battery charging exclusively, to make it clear that there is no mechanical connection from the gas engine to the wheels.

They aren't the only ones to do this, Nissan does for their E-Power system as well, but I've posted that claim followed by a video from one of their lead engineers explaining how it actually works, and it's as I've described, and it how the Ramcharger works, and it's how they all must work to be practical.