Battery Operated Winnebago?

[jimandsue60]

Look Here

Jim

[jimandsue60]

Look Here

Jim

[smlranger]

That surely is interesting. I would think a hybrid (gas or diesel with electric) might be more realistic.

[tderonne]

Um, yeah. The big car companies are having trouble developing a realistic electric car that can go 40 miles on one charge, and it'll weigh like 3000 pounds. 800 miles and 25,000 pounds, it'd take 55,000 pounds of batteries!

Some numbers:

7.5 MPG at 60MPH is roughly 120HP. That's just shy of 90,000 watts. It'd use 90 kW-hours in an hour. That'd require 7500 amp-hours from a 12v battery. That's 33 Trojan T105's. 800 miles/ at 60 MPH is 13.3 hours. It'd take 440 T105's, that would weigh 55,000 pounds. And that's at 100% efficiency, and a simple 60 MPH cruise.

Like I said, um, yeah.

[ChasA]

I've got a bridge for sale. Uh Hu.

[MrTransistor]

How about that 5-minute charge time! I figure something like ˜16,000' Amps. at 240VAC. It just seems like these people have forgotten their High School Physics and Chemistry courses. I wonder who the sponsors are.

I am not going to hold my breath.

2804 Miles
56.5 Hours
Longest Leg = 215 Miles
23 Recharges = 115 Minutes
Hence 55 Hours of driving
Average driving speed = 51 MPH
(hard to do with a top speed of 60 and stopping all the time to recharge)
Weight of 3 ea. 100HP motors to get over the hills = 3600+ lbs.
Most Battery capacity needed (215m) = 322.5 kW Hours
Power required to recharge in 5 minutes = 3.87 MWatts
480 VAC at 8062.5 Amps.
Max. Current rating of ˜0000' wire = 482 Amps.
Of course, this assumes zero wind and as stated by Tim 100% efficiency.

Still, it's a pretty Winne.

Ooh, Ooh, I figured it out! A generator truck will be along to push.

[porscheracer]

I don't want to be in the control center for the utility when that 3.8MW drop hits the line.

[NeilV]

The most realistic one I have seen so far was an effort by an electrical engineer out in California to convert a Honda Civic (CVCC ?) to a full electric. He did not use lead acid batteries and was interested in a commuter vehicle for the round trip drive to work at highway speeds, less than 100 miles round trip.

What he came up with used a 220 volt AC motor with a large inverter along with a thyrister pack (like a photo flash capacitor) for bursts of power for excelleration. Suspension upgrades and high pressure tires were involved also to carry the extra weight. As far as I can recall a standard tranny worked best.

If I can find his link I will post it here for those interested.

Another consideration is what my dad did when stuck on abandoned Japanese islands in the 1940's while waiting for pickup. He would make a still and mount it on one of the abandoned trucks and generate alcohol or methane from the local vegitation so he could drive around the islands instead of walking. I wish I had paid more attention to how he did it. He graduated from MIT in 1927 with an engineering degree.

[Hikerdogs]

Unfortunately here in Wisconsin the cost of our license plates is determined by the weight of the vehicle. The added weight would bring our Adventurer close to the 80,000 lb maximum @ 75,500 lbs. That would change the registration fees from about $150.00 to slightly less than $2000.00

With all the modifications necessary to handle the added weight you'de probably be over the 80,000 lb maximum and have to pay additional overweight fees.

[Outbumn]

I have wondered if a motorhome could operate like a diesel electric train. Every motorhome has a generator and inverter onboard. The question would be how big an electric motor would be needed to match the HP and torque of a diesel in a Winnie. And would the motor weight the same as the diesel engine.

[parmm]

There is one successful sports car, the Tesla Roadster, operating on lithium batteries. Lots of little lithium batteries. 6,831 lithium-ion cells. Charge time is 3 1/2 hours. Guess it could be done, but can you vision all those required batteries for the torque needed to move a motorhome. Little lithium-ion batteries like used on a lap top!

[Dsouthw524]

I have wondered why we do not have a systemsimilar to the idea Outbumn described or the one used by earth movers in the construction iidustry for earthmovers. They use a motor to create the electric and use motors in the wheels to move massive amounts of earth.

[Hikerdogs]

Most continuous duty earth moving machines use either a diesel engine to run a hydraulic pump and have hydraulic wheel or track motors, or have a standard transmission type drive train.

Only the most sophisticated and expensive machines use a diesel engine running a generator and electric wheel motors. Expensive being $2,000,000.00+ per copy. These machines are extremely expensive to maintain and are not yet practical for an RV application. You would have to have pockets as deep as Bill Gates to buy and maintain one.

[MrTransistor]

Could a diesel over electric RV be built? Well yeah, but why would you want to? Trains use this method because a clutch or torque converter would probably burn out before you got the train up to speed the very first time.

Trains pull dead weight, millions of pounds, and wind drag as a ˜percentage' of Horse Power required is almost negligible. The diesel is allowed to run at it's most efficient RPM and the power to the drive motors is controlled by varying the output of the generator by changing the field current. And weight is a good thing for a Train Engine.

A very easy way to control 7000+ HP, but not as efficient as a clutch and transmission. The generator has efficiency losses as do the drive motors. The ease of control and the optimum RPM make the inefficiencies well worth the design.

Boats or Ships use a relatively simple transmission and vary the RPM because the prop in the water allows for slippage and usually, only forward and reverse are required. A Submarine (non nuclear) on the other hand needs electric drive because it must rely on battery power when submerged. Extremely big batteries I might add. I recall something like 2,000 lbs. per 2.2 Volt cell times a couple of hundred cells. (someone in the Navy can correct my figures)

Subs on battery power don't go very fast because the drag of the water is extreme compared to pushing an RV down the road or a Train down the track even with all that Amp./Hour capacity. And since electric must be used when submerged, it makes since to use the diesels to turn generators to supply both the battery recharge current and the drive motors. Eliminates the clutch and makes the gearing simple as well. And again, weight (and price) is not an issue.

But an RV... not worth the weight or efficiency penalty even if price is no object.