Hybrid powered RV

[BandSA]

Hi All,

Have been kicking around a idea that a friend and I were discussing a while back...a hybrid powered motorhome. Some of this goes back a few years for me, as our son gave me a website that had a article about a guy in Iowa that was taking the carbs off older cars, think 60's/70's. He took the carb, cut it in two, thought outside the box, and came up with a carb that on the older cars would give them unreal mileage. I'm talking going from the teens to upwards of high 90's. Apparently he did a car for ZZ Top, mid 70's Olds, 455 ci engine, went up to 97 mpg! He also did a Hummer (H1) that he put super capacitors under the back seat, turbine generator, and got 60 mpg. That beats a Prius!

So, in thinking on all of this, I'm turning to the best source of information that i know of: You Guys!

Is it feasible, possible to do something like this? I'm thinking of what kind of mileage that would give to your coaches, our trucks, etc...

I know up front that it will cost some big amount, but what size of electric motor would be required?

But at any rate this would be a good thing to think of, maybe do(?) these kind of things to our units. Maybe even get the manufacturers in on it, to see what they could come up with.

Just thinking on these things like this, seeing maybe it could come to pass.

[pasdad1]

Hybrid cars really only get the benefit of the electric component when in stop and go driving....using the regenerative brakes to recover lost energy. When hybrid cars are taken on the highway, the engine never stops, and they get the same mileage as a conventional engine chassis.

Since RVs spend most of their drive time in the highway going 60+ MPH, the electric motor would not provide much assist or mileage savings.

The other issue is aerodynamics. Motorhomes have lots of wind drag because of that huge box shape.

When it is feasible, and provides a benefit you can expect to see the technology in over the road trucks.....as small gains in MPG translate to money savings for the big trucking companies.

[cj23andout]

My stop and go driving in this part of the country is up and down with lots of winding roads.

Our hybrid car actually does better on the highway around here than it does in town with stop and go. We have an earlier generation 2007. It gets 33MPG all around. I can get it to 40 on the highway.

The battery and electric motors do assist on hill climbs. Then, on the way down, coasting recharges the battery.

I have to use the engine brake on our gasser. Diesels have exhaust brakes.

No reason why an RV couldn't benefit from a hybrid system.

Our Camry recharges when coasting. It also has a "brake" mode. When you want to slow down, you "downshift" into "B". That engages the recharging system more firmly that when coasting and slows the vehicle while it captures that energy and puts it in the battery bank. We are at 89,000 miles on the original brakes. Must be a benefit there too?

One of the knocks on a hybrid car is that you have to lug around a big battery bank. Well, RVs lug around a big battery bank that is doing nothing while rolling down the highway. May as well put it to use.

The problem with making an RV on a hybrid system is that there are not enough buyers to support the R & D. RVs will see a hybrid system after (if) it becomes widespread in medium duty trucks.

[Raining Star]

Originally Posted by pasdad1

Hybrid cars really only get the benefit of the electric component when in stop and go driving....using the regenerative brakes to recover lost energy. When hybrid cars are taken on the highway, the engine never stops, and they get the same mileage as a conventional engine chassis.

Since RVs spend most of their drive time in the highway going 60+ MPH, the electric motor would not provide much assist or mileage savings.

The other issue is aerodynamics. Motorhomes have lots of wind drag because of that huge box shape.

When it is feasible, and provides a benefit you can expect to see the technology in over the road trucks.....as small gains in MPG translate to money savings for the big trucking companies.

That's certainly not what I experience in my Ford C Max hybrid. As long as I'm at 65mph or less the electric motors are contributing nicely. A bit above 65 and they are out of the game and its gas engine alone. My best gas mileage comes at a steady 45.

Now compared to gas only vehicles hybrids have the biggest advantage over the competition in stop and go traffic, but relative to themselves a steady moderate speed provides the best mileage available.

[pasdad1]

Originally Posted by Raining Star

That's certainly not what I experience in my Ford C Max hybrid. As long as I'm at 65mph or less the electric motors are contributing nicely. A bit above 65 and they are out of the game and its gas engine alone.

This doesn't seem efficient, as there are losses in generating the electricity to keep the electric motors turning full time. If the gas engine is already running, it should power the drive train alone, unless the electric motors just assist for short periods i.e. Up inclines, or when acceleration is needed.

When the motors assist they are taking power from the battery. If they needed all the power to run from the engine driven generator, the power gain should cancel itself out....i.e. the gas engine would sacrifice horse power to generate the electricity, only to get part of that power back as horse power from the electric motor. Then what you would have is a "series" hybrid, which is what the older model GM Volt used to be. The C Max, Prius, Escape hybrid are all parallel hybrids. The newer model volt has changed to a parallel design as well because it's more efficient and gets better MPG.

I have the Mercury Mariner hybrid which is the larger more powerful older cousin to Cmax.

[Murf2u]

Originally Posted by BandSA

Have been kicking around a idea that a friend and I were discussing a while back...a hybrid powered motorhome.

Some of this goes back a few years for me, as our son gave me a website that had a article about a guy in Iowa that was taking the carbs off older cars, think 60's/70's. He took the carb, cut it in two, thought outside the box, and came up with a carb that on the older cars would give them unreal mileage. I'm talking going from the teens to upwards of high 90's.

There's lots of urban myths about BS like this.


The fact is it takes 'X' amount of BTU's to produce 'X' amount of HP, and it takes 'X' amount of HP to move the vehicle.


The ONLY way to get a five-fold increase in mileage is to burn gas with 5 times the BTU content, or to only use 20% as much HP as before.

[Hit_the_Rhod]

Originally Posted by BandSA

Hi All,
guy in Iowa that was taking the carbs off older cars, think 60's/70's. He took the carb, cut it in two, thought outside the box, and came up with a carb that on the older cars would give them unreal mileage. I'm talking going from the teens to upwards of high 90's. Apparently he did a car for ZZ Top, mid 70's Olds, 455 ci engine, went up to 97 mpg! He also did a Hummer (H1) that he put super capacitors under the back seat, turbine generator, and got 60 mpg. That beats a Prius!

Call me a skeptic, but I would really have see something like this with my own eyes . . . (and search the car for the extra gas tank that appears to be allowing it to get 97 mpg!)

Same era, "The '70's show", quote "There's this car . . . that runs on water . . . .!"

Just send me $999,999.00 via Western Union to pre-order yours, and we'll get back to you as soon as we have the production models built! Probably sometime after 2060 or so!

[twinboat]

You need to look at the users who would benefit from Hybrid power, if it worked.

USPS, UPS, Fed X, Taxi Cabs and any kind of people or package moving service.

Its just not cost effective.

The only industry that took on electric vehicles in a big way was Golf Cars. Slow, lightweight, daytime use, carts that can be recharged overnight.
For the limited amount of use, they carry 600 to 800 lbs of battery.

[Sweetbriar]

The current level of technology doesn't work well with a medium or heavy vehicle. Wait a few more years and it will be there. Energy density, and recharge rate verses energy consumption still needs a bit more work. Takes a lot more energy to push a seven ton brick down the road than a two ton bullet shaped daily driver. Everything would need to be scaled up dramatically which works against any gain due to the added weight.

The package delivery companies are driving the issue for us concerning vehicles of our size. If UPS, Fed-Ex and such can save as little as $.10 a mile over the life of a delivery vehicle they would jump on it. Scale up the savings to their local or region delivery volume and the savings is very large. Besides the cost savings there is also the PR bonus a fleet of hybrid vehicles would produce. I suspect we'll see it first with the Sprinter size platform and if will grow from there.

[Gary RVRoamer]

I'll agree with most of the nay-sayers above. There are many reasons why hybrid power is not as good a fit as it might appear.

However, it seems to me that a heavy vehicle (motorhome or truck) could benefit from an electric motor assist that cut in when acceleration is needed. Basically some extra horsepower under load, allowing the main engine to be smaller or less powerful. Since motohomes need a battery pack anyway, this may not be as expensive or as much extra weight as would normally be the case in a car or truck. But nobody is going to develop and build that technology just for the small motorhome market. Our chassis are derived from production commercial vehicle chassis. That's true even for Class C coaches, e.g. the E450 van chassis.

There are companies working on this sort of thing, e.g.
Electric Hybrid Trucks, Diesel Electric Trucks | HybriDrive®
The Latest Developments in Hybrid-Electric Medium-Duty Trucks - Article - TruckingInfo.com
FedEx’s New Electric Trucks Get a Boost From Diesel Turbines | WIRED

[JFXG]

Originally Posted by BandSA

.....goes back a few years for me, as our son gave me a website that had a article about a guy in Iowa that was taking the carbs off older cars, think 60's/70's. He took the carb, cut it in two, thought outside the box, and came up with a carb that on the older cars would give them unreal mileage. I'm talking going from the teens to upwards of high 90's. Apparently he did a car for ZZ Top, mid 70's Olds, 455 ci engine, went up to 97 mpg! He also did a Hummer (H1) that he put super capacitors under the back seat, turbine generator, and got 60 mpg. That beats a Prius........

It's the Great Cleveland Carburetor Conspiracy, all over again!!!!


John & Diane, fulltiming since '12
'02 DS, FL, Cat, '04 Element
NHSO RVM103

[Raining Star]

Large vehicle hybrids would be an extremely desirable product to the massive truck buying market, and certainly not limited just to the tiny motorhome sub market. The limitation, as it was explained to me, is that the size of an electric motor big enough to provide meaningful power to large vehicles simply won't fit realistically into truck frames.

Remember that what we call diesel locomotives are technically called diesel electric locomotives, and those thousands of tons of railroad train, that we wait long minute to pass, are all being pulled completely by electric motors alone, the diesel engine used solely to power the generator. Electrical motor size alone is the only reason we haven't had electric trucks long before. Thus saith the electrical engineer who explained it to me.

[wanderso]

We have hybrid buses in our area. They are the size of the typical diesel pusher motorhome. Some may say, "well, buses do more stop and go than an RV", but these particular buses are those for commuters and they do spend quite a bit of time on the highway. Converting these buses that already look like a motorhome seem to be a no brainer.

In the west there are many places on the highway that are not flat. I see countless examples of where a hybrid would benefit on the down hill side, especially if the motorhome is also pulling a toad/dinghy.

Now I realize that locomotives are much different than on road vehicles but they use electric motors for propulsion. Seems that one day we will figure a similar system for those triple-trailer trucks that I regularly see on the interstate.

My speculation is that the reason comes more down to the size of the potential market than the technology limitations as shown by the bus example above.

[Jim_HiTek]

If you're going to build a hybrid RV, look at the electric forklift industry for both inspiration, electronic controls (EV-1), relays, contactors, and motors in the 200-400 HP range. And note the massive battery it takes to get 6-8 hours of work at moderate speeds before a recharge is needed. Adding a 10KW generator helps with recharging of course.

Using DC motors gives another benefit, no brakes (well, maybe no rear brakes) are needed so you save all that weight from calipers and rotors.

It would be fun to work on this sort of project, as a former Hyster employee, electric forklift engineering division. So let's rent a empty building in the Mojave desert, install RV sites for volunteers, and get busy!

But I think you'd be looking at machines under 20,000 gross and not much range/day.