Winnebago Electric Motorhome on a F-53 chassis

time2roll wrote:
I still think a plug-in hybrid system could work great in a large RV. Get rid of the transmission and all the related issues and service. Electric only would power the MH to about 45 mph and then the ICE would have a single clutch to direct connect for highway travel. Maybe 200hp diesel and 300hp electric to work together climbing hills etc. Maybe 50 mile electric range with the ICE generating power if needed. Just something to give balance until technology is able to go full EV at a reasonable price.

Hybrids just aren't that useful for a vehicle that spends most of its time at highway speeds. You don't save a lot of weight or space by downsizing the ICE, then you add a lot of weight and cost and lose a bunch of space for the hybrid side, especially one big enough to do 45 mph and also be able to get the MH up a mountain pass when needed.

Everyone already complains about their CCC number. My motorhome has 2500 lbs of CCC. Full load of water I'm down to 2000, now make it a hybrid and your probably down to 1000 lbs and a few cargo compartment are lost and add how much to the cost for almost no benefit in highway mileage.

time2roll wrote:
I still think a plug-in hybrid system could work great in a large RV. Get rid of the transmission and all the related issues and service. Electric only would power the MH to about 45 mph and then the ICE would have a single clutch to direct connect for highway travel. Maybe 200hp diesel and 300hp electric to work together climbing hills etc. Maybe 50 mile electric range with the ICE generating power if needed. Just something to give balance until technology is able to go full EV at a reasonable price.

Actually, you could get away with much smaller power plant. On level ground, you only need around 150hp to maintain freeway speeds...then you can use the batteries to handle hills and acceleration...assuming parallel hybrid, 150hp electric would give you a peak output of 300hp with lots of torque (which is what gets you up steep grades).

Biggest issue is manufacturers aren't going to build just for the RV market...one option for MH would be a lot of city buses have gone hybrid If they could put the drivetrain in a MH that might work...only problem is those drivetrains are significantly more expensive than a standard diesel...it works for a city bus running 16hr per day every day where they can justify it based on fuel savings but for a MH that might do 5000miles per year mostly freeway (where hybrid doesn't gain you much), I suspect it would be a tough sell outside of those who just want to prove how green they are.

Chainwright wrote:
No no no. No pie in the sky nothing. At the end of the day it's becoming about efficiency. You have to ask yourself what is MORE efficient, a Combustion Engine or an Electric motor?
The second law of thermodynamics puts a fundamental limit on the thermal efficiency of all heat engines. Max efficiency of combustion engines fueled by petroleum is 20-25%, diesel tops off at 40%. electric engines can be more than 90% efficient and even up to 98% efficient, but even at 75% it would be a win win.
Yeah, back in 1906 Automotive technology was "Pie in the sky tech" too. Well we see how that went.

Problem with your analysis is you've included the full efficiency of IC engines but omitted the least efficient part of battery EV's
- You still have inefficiencies in the generation.
- Inefficiencies in transporting the electricity
- Inefficiencies in battery charging.
- Plus the inefficiencies in the electric motor.

When you do an apples to apples comparison...electric is no more efficient and in most cases worse.

Of course, the big issue is really energy density. Even if we buy your supposed efficiency, batteries hold so little energy that it's not even close on range.

jharrell wrote:

time2roll wrote:
fair enough. The numbers are probably right. Good to have a baseline as it will just improve from here. Battery cost needs to keep declining along with energy density. We are not at the end of the curve yet IMO.

I used to think how great it would be if an RV was setup like a diesel electric train, maybe multiple generators for redundancy etc. But once you do the math you realize how that just not feasible. Trains and some boats do it for specific reasons while accepting the downsides. Those downsides are just too great for weight and size constrained road vehicles.

I still think a plug-in hybrid system could work great in a large RV. Get rid of the transmission and all the related issues and service. Electric only would power the MH to about 45 mph and then the ICE would have a single clutch to direct connect for highway travel. Maybe 200hp diesel and 300hp electric to work together climbing hills etc. Maybe 50 mile electric range with the ICE generating power if needed. Just something to give balance until technology is able to go full EV at a reasonable price.

Chainwright wrote:
No no no. No pie in the sky nothing. At the end of the day it's becoming about efficiency. You have to ask yourself what is MORE efficient, a Combustion Engine or an Electric motor?
The second law of thermodynamics puts a fundamental limit on the thermal efficiency of all heat engines. Max efficiency of combustion engines fueled by petroleum is 20-25%, diesel tops off at 40%. electric engines can be more than 90% efficient and even up to 98% efficient, but even at 75% it would be a win win.
Yeah, back in 1906 Automotive technology was "Pie in the sky tech" too. Well we see how that went.

Efficiency is not really comparable. The electricity must come from somewhere, currently in the US the majority is from a heat engine running from fossil fuels. So while the electric motor is 90% efficient at turning electricity into motion, the power plant is still turning fossil fuels into motion limited by Carnot. Then you have losses turning motion into electricity in the generators, then you have transmission losses to the charger, then you have battery losses storing the electricity, then finally you have the electric motor losses.

So saying a diesel is 40% efficient while an electric motor is 90% is apples and oranges. The reality is much more complicated, electric cars can be more efficient end to end but its much closer than the straight motor efficiency difference. If you look at what Tesla is claiming for cost per mile for the semi its 20% more efficient than diesel, but I believe they are including maintenance costs to make thing look better and some low kwh electricity cost. So it actually a little closer than that for actual fuel efficiency.

wildmanbaker wrote:
A lot of these posts are about a "Pie in the Sky" tech. There are a number of things that has to solved first. First and foremost, There is NO FREE LUNCH! Just like our deep cycle batteries, their is a max charge and discharge rate for these lithium batteries. Remember, Energy can neither be created, or destroyed, but changed from one form to another. Your not going to end up with more than you started with, and you will not break even, unless you or someone else can change the Laws of Physics. To get batteries with a fast charge rate, costs money, as some way to cool the battery on the inside must be provided. Power companies will limit the power draw at any one time, to keep the grid up. IT would be great to have a Hybrid MH, but even that is a LONGGGG way off. There are a great many problems to solve before something like a long haul truck happens, or MH for that matter. I guess boondocking will come to an end then also.

No no no. No pie in the sky nothing. At the end of the day it's becoming about efficiency. You have to ask yourself what is MORE efficient, a Combustion Engine or an Electric motor?
The second law of thermodynamics puts a fundamental limit on the thermal efficiency of all heat engines. Max efficiency of combustion engines fueled by petroleum is 20-25%, diesel tops off at 40%. electric engines can be more than 90% efficient and even up to 98% efficient, but even at 75% it would be a win win.
Yeah, back in 1906 Automotive technology was "Pie in the sky tech" too. Well we see how that went.

Chainwright wrote:

That's the Thing: In technology we will NEVER be "at the end of the curve." That's what many seem to be overlooking. Whatever strides we have made so far in the EV and alternative fuel industry DOES not stop here, today. AND Many are treating it as such. in 2030, most of the world is prohibiting the Sale of petroleum Combustion Engines. Outcome? Our Auto industry will be none existent because no one will buy OUR Cars, because they'll be Illegal.

It's not as though battery technology, or most any technology, develops smoothly. Generally there's an occasional breakthrough--a new approach or way of doing things or chemistry--and then a period of incremental improvements, which have increasingly smaller payoffs as the easy improvements have been done already. About the only technology that I can think of offhand that has somewhat bucked this general trend is microelectronics, where the progression towards more and more dense circuitry has been remarkably steady for quite a few decades...though with ever increasing development costs to maintain that.

Far more likely than internal combustion engines (and vehicle powered by them) going away, in my opinion, would be running them on non-petroleum derived fuels, such as alcohol or hydrogen or wood gas. That's not to say that many won't be served by electric vehicles, but I think they're a long way from being universal. For tooling around town and commuting electric cars make a lot more sense than they do for long-distance vacation travel or over-the-road trucking,

I think many here, myself included at times, are looking at this from a U.S end consumer point of view. Winnebago is a Company 1st. Their objective is to sell as many of these as possible. What they don't tell you is....They don't care WHO buys them. LOL. if they sell these rigs to the other 194 countries, the US market is a none factor. The Class A industry is happy to sell 7k-8k MHs per yr. Imagine how happy winnebago would be to sell 100 per month? (if possible). Like I said previously, to us 125-150 miles is nothing, but in Europe, it's alot. If you're RV'ing through Europe and Enjoying as many Wineries, Breweries, Castles, Beaches and lakes as you can that 125 miles will be a non factor. It's a global economy now, it's not all about Us.

A lot of these posts are about a "Pie in the Sky" tech. There are a number of things that has to solved first. First and foremost, There is NO FREE LUNCH! Just like our deep cycle batteries, their is a max charge and discharge rate for these lithium batteries. Remember, Energy can neither be created, or destroyed, but changed from one form to another. Your not going to end up with more than you started with, and you will not break even, unless you or someone else can change the Laws of Physics. To get batteries with a fast charge rate, costs money, as some way to cool the battery on the inside must be provided. Power companies will limit the power draw at any one time, to keep the grid up. IT would be great to have a Hybrid MH, but even that is a LONGGGG way off. There are a great many problems to solve before something like a long haul truck happens, or MH for that matter. I guess boondocking will come to an end then also.

"fair enough. The numbers are probably right. Good to have a baseline as it will just improve from here. Battery cost needs to keep declining along with energy density. We are not at the end of the curve yet IMO."

That's the Thing: In technology we will NEVER be "at the end of the curve." That's what many seem to be overlooking. Whatever strides we have made so far in the EV and alternative fuel industry DOES not stop here, today. AND Many are treating it as such. in 2030, most of the world is prohibiting the Sale of petroleum Combustion Engines. Outcome? Our Auto industry will be none existent because no one will buy OUR Cars, because they'll be Illegal.