Powerboost or RamCharger

[GrandpaD]

I hadn't seen it mentioned but Volkswagen is resurrecting the Scout brand and one of their projected 2028 releases is the "Terra" pickup which will also have a "range-extending" generator similar to the Ramcharger.

https://www.caranddriver.com/news/a62699830/2028-scout-traveler-terra-revealed/

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[Calson]

Many EVs lack a spare tire and so with a flat one needs to hire a flat bed tow truck and have the vehicle taken to a tire shop.

We opted for a Toyota plug-in hybrid, their Rav4 in 2022 and it has been a great AWD SUV. I would never buy a Jeep with their terrible reliability record. If someone insists on a Jeep, then I would lease one so you have the option of returning it to the leasing company.

 

[Snakebitten]

EV's are far from the only vehicles that spare tires are being de-contented on.
And not every flat tire would require a tow truck to a tire store. Depending on flat, there are options.

How is an EV with a flat tire any different than a vehicle with an ICE and a flat tire? ??

 

[Samson16]

How is an EV with a flat tire any different than a vehicle with an ICE and a flat tire? ??

Irrational disdain?

 

[HammaMan]

Think of all of the electrons that escape when an EV gets a flat!

The bigger issue is the dumb trend of not including spares. If I'm going distance and can drive at night, spare is a must. Had a small piece of steel in the road that did a real number on a tire. TPMS triggered within 5 minutes and through 2 strokes of luck I made it to a gas station and despite the size of the slit, the can of fix-a-flat I put in it did its magic. Next morning I took it to a discount tire and got it patched for free. It was a rental so despite my vehicle preps, did me little good in a rental. DT couldn't even find the slit until I pointed it out and it was a solid 3/8" gash. Couldn't believe fix a flat was effective on it.

 

[amschind]

The PHEV series hybrid drivetrain layout is superior to a standard parallel hybrid drivetrain. The issue is that for highway driving, the series hybrid loses a few points of efficiency because it's converting rolling motion into electrons and back into rolling motion. One way to avoid that is to do what Honda did with the Accord Touring Hybrid, and have a high speed clutch between the engine and drivetrain.

The bigger issue is that a series hybrid gets rid of a lot of breakable parts. This positive reliability effect, and the efficiency benefit, are magnified with hub motors vs a centralized electric motor and CV shafts. Finally, a series hybrid is an enhancer for the prime mover, whether that's a battery, a piston engine, or something more exotic like an advanced piston engine, a turbine engine or combined cycle turbine, or even a fuel cell.

A Dodge V6 isn't a great powerplant, and it is too big for a series hybrid. Ideally, you want something small that is either running at its best efficiency point and charging the battery or off. My thoughts are that an HCCI 2-stroke, possibly even a "novel" design like a flat opposed piston or deltic layout, would be ideal, even more so with a bottoming cycle like BMW's turbosteamer. Longer term, a direct carbon fuel cell coupled with a TEG bottoming cycle has so many reliability benefits (the only moving part on the prime mover would be a set of fans) will take over.

The Ramcharger is closer to where things are headed, but I think that it lacks some key innovations that will one day make that a slam dunk. The PB is a great truck, but there is A LOT of needless complexity that it expensive and challenging to remove.

 

[Samson16]

One way to avoid that is to do what Honda did with the Accord Touring Hybrid, and have a high speed clutch between the engine and drivetrain.

But the RamCharger doesn’t have a “drivetrain”. The ICE is connected to a generator which charges a battery bank through an AC/DC converter power supply. The HVB then feeds a DC/AC inverter which provides power to the electric drive motors.

Something like that. ?

 

[dochawk]

The issue is that for highway driving, the series hybrid loses a few points of efficiency because it's converting rolling motion into electrons and back into rolling motion.

I'm decades from my undergraduate physics and engineering at this point, but it seems to me that, while the generator is running with the vehicle in motion, it should be possible to split its output between the drive and the battery, rather than having to go in and back out of the battery. The battery could either charge with the rest, or supplement the output. Either way, the generator could always run at its peak efficiency.

 

[amschind]

I'm decades from my undergraduate physics and engineering at this point, but it seems to me that, while the generator is running with the vehicle in motion, it should be possible to split its output between the drive and the battery, rather than having to go in and back out of the battery. The battery could either charge with the rest, or supplement the output. Either way, the generator could always run at its peak efficiency.

It is possible....that's a Powerboost or any other parallel hybrid. The cost is complexity: divorcing wheel RPM from engine RPM eliminates most of the parts that we associate with a drivetrain. A series hybrid doesn't want or need a transmission or differentials or driveshafts or, with hub motors, CV shafts. Added up, the 1-3% hit from each of those geared linkages can add up to more than the losses from conversion to and back from electrons.

 

[amschind]

But the RamCharger doesn’t have a “drivetrain”. The ICE is connected to a generator which charges a battery bank through an AC/DC converter power supply. The HVB then feeds a DC/AC inverter which provides power to the electric drive motors.

Something like that. ?

Yes, the Honda system was built to eke out maximum MPGs. That car actually gets mid 40s, so they did something right.

 

[HammaMan]

A series hybrid doesn't want or need a transmission or differentials or driveshafts or, with hub motors, CV shafts. Added up, the 1-3% hit from each of those geared linkages can add up to more than the losses from conversion to and back from electrons.

Most EVs are geared somewhere between 3 and 9:1, still retain a diff and driveshafts/half shafts with CVs on either side of each one. Hub motors just aren't quite stout enough yet. Perhaps a hybrid approach with it residing at the vehicle side between upper and lower A arms with a single CV joint may be a better solution for now. Not sure how that unsprung mass in the wheel would translate to drivability. Between motors, cabling, cooling, and planetaries, that has to add ~40lbs/wheel. Can't be good for RQ.

I'm decades from my undergraduate physics and engineering at this point, but it seems to me that, while the generator is running with the vehicle in motion, it should be possible to split its output between the drive and the battery.

It's not really that complicated. It's just a common DC bus. By adjusting the voltage it can charge the battery or just float it while providing the amperage for the motors. Given that it's a 130kW generator and we already have the figures for the power required to drive the vehicle, the generator is very much intended to 'quickly' charge the battery and power back down.

Most EV trucks get roughly 2 miles per kWh. At 70mph that's 35kW worth of energy being consumed to maintain speed. In max case, that'd be 1hr generator run w/ ~2hr EV only. With smart route planning and all efficiencies know for say an "eco" mode (including weather/terrain), it may be more prudent to run the ICE at an optimal fuel burn. It'd really come down to very good route planning / suggesting. Take for instance the desire to stop somewhere to eat and charge.
Simply put, stelantis needs to either sub out to tesla or hirer some of their engineers to truly maximize the truck's potential.

Tesla's prediction system is truly unparalleled. People can route through deserts / mountains / headwinds and still hit a charger within just a couple %. Tesla's telemetry is pretty impressive thorough -- they can extrapolate ground wind speed from vehicles that just passed through an area. This is what happens when you use telemetry to improve the product - just their ADAS use alone has reported home at least 30bil miles of data. Legacy auto really needs to get with the program on improving products instead of trying to monetize customer data.

 

[v8440]

Stellantis has been either firing or laying off engineers lately, can't remember which. I doubt they're forward thinking enough (or maybe even financially able) to hire a bunch of tesla engineers.

 

[amschind]

Most EVs are geared somewhere between 3 and 9:1, still retain a diff and driveshafts/half shafts with CVs on either side of each one. Hub motors just aren't quite stout enough yet. Perhaps a hybrid approach with it residing at the vehicle side between upper and lower A arms with a single CV joint may be a better solution for now. Not sure how that unsprung mass in the wheel would translate to drivability. Between motors, cabling, cooling, and planetaries, that has to add ~40lbs/wheel. Can't be good for RQ.

It's not really that complicated. It's just a common DC bus. By adjusting the voltage it can charge the battery or just float it while providing the amperage for the motors. Given that it's a 130kW generator and we already have the figures for the power required to drive the vehicle, the generator is very much intended to 'quickly' charge the battery and power back down.

Most EV trucks get roughly 2 miles per kWh. At 70mph that's 35kW worth of energy being consumed to maintain speed. In max case, that'd be 1hr generator run w/ ~2hr EV only. With smart route planning and all efficiencies know for say an "eco" mode (including weather/terrain), it may be more prudent to run the ICE at an optimal fuel burn. It'd really come down to very good route planning / suggesting. Take for instance the desire to stop somewhere to eat and charge.
Simply put, stelantis needs to either sub out to tesla or hirer some of their engineers to truly maximize the truck's potential.

Tesla's prediction system is truly unparalleled. People can route through deserts / mountains / headwinds and still hit a charger within just a couple %. Tesla's telemetry is pretty impressive thorough -- they can extrapolate ground wind speed from vehicles that just passed through an area. This is what happens when you use telemetry to improve the product - just their ADAS use alone has reported home at least 30bil miles of data. Legacy auto really needs to get with the program on improving products instead of trying to monetize customer data.

The unsprung mass IS an issue, but of all entities Porsche did some prototype work and found that the ability to actively vector torque to each wheel completely independently of the others CAN more than compensate. Can being the operative word, but that's software, it's a known problem with a known solution, so that's addressable. The larger issue is, as you point out, the bearings, which are going to take all of the bounces and bumps and potholes with only the tires to cushion them. These bearings WILL be a wear item....ceramic would get crunched and tool steel well get squished, so the bigger issue will be making the bearings sufficintly long lived while also making them cheap and easy enough to replace so that customers don't just drive around on smoking wheel hubs.

With regard to gearing, trucks and consumer vehicles have it easy, as one well chosen gear ratio will cover all of the speeds that the vehicle SHOULD require. Contrary to popular belief, electric motors do not have a completely flat torque curve, and actually lose quite a bit of efficiency outside of a 1500-2000 RPM range. That's still wide enough to allow for a single gear ratio, though above about 75 MPH it is really nice to have another gear. I wonder if the big innovation that pushes hub motors isn't "drivetrain" related at all, but brake related. Regenerative braking at a sufficiently high mechanical DISADVANTAGE could mirror the stopping power of conventional brakes, but that requires at least a 2 speed "transmission" that is small enough to fit at all 4 corners as unsprung mass AND sufficiently simple and reliable to replace hydraulic brakes. So you would wind up with a 7:1 drive ratio and a 1:20? brake ratio. The one thing that could allow such a system to fit inside the size and weight restrictions is that the electric motor IS its own synchronizer. I.e. the wheel RPM is X, and if both sets of gears ("brake" and "drive") are disengaged, the electric motor can be spun up to match the wheel RPM with sufficient accuracy to allow the gears to mesh.

That part actually sounds doable, but the tougher part is making it "fail safe" rather than "fail the brakes don't work". I think you would still have to have a hydraulic emergency backup, but potentially one that is allowed to run from a reservoir and damages components if engaged (thus saving weight and cost vs a regularly used hydraulic system).

Anyway, back to the OP's point, there are A LOT of innovations which we are just scratching the surface of, so any vehicle bought today will be a transitional model between an 1948 F100 and whatever the future holds, leaning more toward the F100. While the Ramcharger is closer to the future in some ways, it is still sufficiently far away that it doesn't have some huge advantage. If I had to choose again, I would likely still go with the PB.

 

[Suns_PSD]

One of the costs that is never brought up is the purchase and installation of a Level 2 charger for the house. Although there is a technology to get around this, if you have a 100 amp service you’ll need a new service. This is approaching $12k in my area of the country.

From scratch it's typically about $3.5K to have level 2 charging installed in my area assuming you don't need an entirely new panel. That was the quote I got on my old home that was built in the 1980s.

When I had my new house built in 2022, I had EV charging 50Amps pulled in 2 spots in the garage, it was a $490 option each. But I'd still need to buy the actual chargers, and they are another $300-750.

But also, realistically, for a PHEV that gets driven 30-50 miles per day, you can really just use a standard plug to charge it. It'll mostly stay charged but if it doesn't occasionally, who cares? It has an onboard generator to bail you out.

 

[Suns_PSD]

If you need a truck today, well obviously you buy something for sale right now.

If you are shopping for a truck to purchase in 2-4 years, imo a PHEV is the future for anyone short of a Hot-Shotter, or maybe someone that just doesn't have access to an outlet at night.

It's worth noting that certainly Ford will have something similar in time.

To me, the Ramcharger on paper is a dream truck. But I won't be selling my '21 PB to buy one just because spending $50K extra to save $25/ week on fuel, is just really bad math, unless I was buying a new truck anyways.

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