Concieve the electric RV - DIY Electric Car Forums
Go Back  

DIY Electric Car Forums > EV Conversions and Builds > All EV Conversions and Builds

Register Blogs FAQ Members List Social Groups Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 10-27-2008, 02:45 AM
This is Bill This is Bill is offline
Junior Member
 
Join Date: Oct 2008
Posts: 5
This is Bill is on a distinguished road
Default Concieve the electric RV

The electric RV.

Instead of buying a $75,000 -$100,000 brand new RV, what if I bought a used one for $10,000 as a conversion project? The technology has changed very little on the inside so it can be a few years old as long as it is clean and in working order (fridge, sofa/bed, tv, generator, toilet/bath, carpets, etc.).

I don't like driving all day long, so traveling 200 miles at 55mph in one day is great. Besides this leaves more time for camp set up. Some mountain grades can be very steep so the ability to go at least 5% grade at times is a must.

What motor/controller/battery set up will work? Some cities use electric buses so I know its possible to find some heavy duty parts.

Hmmm. Imagine removing the primary ICE and transmission. Could a powerful ac motor(s) be attached straight to the drive shaft and still meet the torque and rpm requirements? Perhaps a gear ruduction assembly would be required. Perhaps a change in the ratio in the diff would be needed.

The existing generator will be left as is to assist in its normal functions (air conditioning, and other ac power) but it will also be able to help slow the main battery packs from depleting. Obviously it would require a much larger generator to keep the batteries from ever depleting but the goal would be to assist in the range bump it from lets say 100 miles electric only to 200 miles using generator. Re-gen braking would be used on all the grade decents and braking during traffic. Obviously this is a minimal amount but every bit helps for range extension.

The long flat roof is ideal for solar panels. If my RV is sitting out doors all the time, then it makes sense to have solar panels. The extra weight and cost is a draw back at first, but the savings over time (and thats what solar is all about) would be great. 99% of the time an RV is sitting around at your storage lot or your house or even the camp ground. I would love to have the sun recharge the batteries for me, sort of like a full tank of gas a week, only not paying $250 and worrying if the gas is getting old as the RV sits through winter. And if my RV is parked in my side yard, then perhaps it's solar energy can be fed back to the utility company's grid, another cost savings plus over time.

When I get to the camp site and pay my $25, I could re-charge the batteries...big gas savings especially the more I use the RV over the years.

Another savings could be the yearly registration. Maybe there is a loop hole for a electric RV and could save hundreds each year.

Most RVs are desinged for their weight and also to pull something like another car or boat. Plenty of room along the frame for all of those batteries. Even if some of the storage compartments have to be sacraficed for batteries that would be just fine. I think lead batteries would be much cheaper at first, but then when you consider that the generator had to be used most of the time during operation, and too much increased weight, in the long run it would be worth while to have higher energy density batteries right from the get go.



Or just not mess with and have a regular motor home with it's factory warrenties and shell out $2000 for gas each trip. Plus all the maint cost.

I've read a lot of these posts and a I'm interested in how this concept can be improved. Good day.
Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 10-27-2008, 03:39 PM
TX_Dj's Avatar
TX_Dj TX_Dj is offline
SPAM Cop
 
Join Date: Jul 2008
Location: Texas, Plano (Dallas)
Posts: 1,499
TX_Dj is on a distinguished road
Default Re: Concieve the electric RV

I'm not saying it's impossible, but fairly improbable to meet your goals.

The Top-Two killers of EV range are weight and drag, something an RV has in abundance.

If it were purpose built from lightweight aluminum and composite materials with a focus on ultra-lightweight materials and the bulk of the vehicle weight made up from lithium batteries, it may be possible to get 200 miles range out of it for $300k+ in EV and vehicle construction costs alone (i.e. a "shell" with nothing inside.)

If someone can make an ERV for a reasonable price, I'll be interested. I've thought for years that considering you can get 50 amp service at most RV parks, it would be simple to roll up, plug in, and recharge while you're camped.

However, an ERV would be really rough to go boondocking, which is my favorite sort of RVing.
__________________
cheers,
dj
"I'm No Expert!(TM)"
A fuel and his money are soon parted...
Reply With Quote
  #3  
Old 10-27-2008, 08:40 PM
ElectriCar's Avatar
ElectriCar ElectriCar is offline
Administrator
 
Join Date: Jun 2008
Location: Reidville, SC
Posts: 1,849
ElectriCar is on a distinguished road
Default Re: Concieve the electric RV

It's way cheaper to buy electricity than do it with solar cells. It'll take longer than you'll live to pay for them likely at todays prices. Wait for Nano Solar's products to hit the market at 1/10 today's cost and you'll be much better off. I think you'll be able to buy them in a year or so. I can't wait!

And wanting an RV to go 100 miles without a recharge is going to be REALLY expensive, a lithium pack surely!

But you never know the answers until you investigate your ideas. Some work out and some don't. Those never attempted never make it!
Reply With Quote
  #4  
Old 10-28-2008, 01:46 AM
This is Bill This is Bill is offline
Junior Member
 
Join Date: Oct 2008
Posts: 5
This is Bill is on a distinguished road
Default Re: Concieve the electric RV

Thank you for the responses. Since the closest vechicle to a RV is a bus, I did a search on hybrid buses, and this company illustrates the feasability. Thought it was interesting so I posted it here.

http://www.advancedenergy.org/corpor...ybrid_tech.php

And I agree that the use of nano solar is ideal, it's so thin that you wouldn't even know that they were up on the roof unless you climbed up the ladder. I wonder if it could be somehow fashioned on the awning for increased solar surface area.

--Bill
Reply With Quote
  #5  
Old 10-28-2008, 03:46 AM
mattW's Avatar
mattW mattW is offline
Super Moderator
 
Join Date: Sep 2007
Location: Sydney, Australia
Posts: 882
Blog Entries: 18
mattW is a glorious beacon of lightmattW is a glorious beacon of lightmattW is a glorious beacon of lightmattW is a glorious beacon of lightmattW is a glorious beacon of light
Default Re: Concieve the electric RV

I certainly don't think it would be impossible. In fact I think it is a pretty good idea. With the combination of a generator, solar panels, a slowish top speed and a huge battery capacity you could certainly get a decent range. If you could go 100 miles then stop for an hour or two for lunch (with the generator and panels going) then drive the other 100 then it would probably be a lot easier/cheaper. What sort of HP do RV's have and what sort of budget do you have for the conversion?
__________________
If I was giving a kWh for every suggested idea of perpetual motion I read, I would probably ironically be able to travel perpetually...
Reply With Quote
  #6  
Old 10-28-2008, 08:53 AM
rfengineers's Avatar
rfengineers rfengineers is offline
Senior Member
 
Join Date: Jun 2008
Location: Gainesville, Florida
Posts: 401
rfengineers is on a distinguished road
Send a message via Skype™ to rfengineers
Default Re: Concieve the electric RV

Just a thought experiment here:

My RV gets about 8-mpg. Using the VERY ROUGH model for EV mileage (36.6kWhr/gal-of-gasoline and about 25% efficiency) my RV should consume about 1150Whr-per-mile. For a 100-mile range at relatively low speed that would require about 140kWhr (to 80% dod). If I ran my 6kW generator and drove 50mph that would knock 10 or 12 kWhr off of the battery requirement.

Based on this, my GUESTIMATE for my RV would be a 100 to 150kWhr battery.

Using 225-AHr 6-Volt lead batteries (e.g. Trojan T105), that would be about 94 units (126,900Whr) for a weight load of about 5734-lbs.

Now, how long would it take you to recharge assuming you had 120-Volt 50-Amp service at a campground? And how long would it take to check and top-off the batteries!?

It is certainly feasible, but is it worth doing?

Joe
__________________

--Conversion-99.99999%-Complete--
http://www.evalbum.com/2283
http://www.zazzle.com/rfengineers
Reply With Quote
  #7  
Old 11-01-2008, 11:35 PM
This is Bill This is Bill is offline
Junior Member
 
Join Date: Oct 2008
Posts: 5
This is Bill is on a distinguished road
Default Re: Concieve the electric RV

I like your GUESS ESTIMATE example!

I agree that using Lead batteries just isn't a good idea. This drives the build cost way up. Its easier to get a loan for a new RV, vs an unsecured loan to do this project.

A lot of gas RV's use Ford Trition V-10 which I think is around 300hp 360ft/lb of torque. That's an incredible amount of hp to match with an electric motor... probablly 700 volt or more system would be required. Expensive and dangerous.

Its ok if the charge time takes a long time, say 14 hours. If I roll into the campsite at 6 pm and leave at 8 am the next day, that isn't really interfering with travel time.
Reply With Quote
  #8  
Old 11-02-2008, 12:08 AM
TX_Dj's Avatar
TX_Dj TX_Dj is offline
SPAM Cop
 
Join Date: Jul 2008
Location: Texas, Plano (Dallas)
Posts: 1,499
TX_Dj is on a distinguished road
Default Re: Concieve the electric RV

I think a 144v system can produce far more than 360 ft/lbs torque. Heck, Crazyhorse makes over 1200 ft-lbs, and I think it's a 300-ish volt system (with gobs and gobs of amps). However, 300 HP = 223 kW... which can be generated by 111 volts @ 2000 amps... or 223 volts at 1000 amps, or 446 volts at 500 amps...

The problem isn't making the power so much as finding something that can handle that power...

Additionally... that 300 horsepower V10 probably only needs about 60-80 HP to push that RV down the road at freeway speeds. Sounds like a job for a large AC drive to me, something, oh, I dunno, in the 440 volt RMS range?

It's do-able... but how much would you want to spend? If you buy a nice RV for 100k, and put 400k into the drive/battery/charger systems, who would you ever resell it to when you no longer need it?
__________________
cheers,
dj
"I'm No Expert!(TM)"
A fuel and his money are soon parted...
Reply With Quote
  #9  
Old 11-02-2008, 12:09 AM
LeTank's Avatar
LeTank LeTank is offline
Senior Member
 
Join Date: Jun 2008
Location: Rocky Mountains (Colorado)
Posts: 547
LeTank is an unknown quantity at this point
Smile Re: Concieve the electric RV

Pretty cool idea. I would use the nice tractor (commerical) 12 volt 800amp lead acid batteries myself for starters. I use them to run part of my house with my solar system and they are great. Can get them at Napa for $189.00 and they have a 72 month replacement warrantee. Worth checking out. Each weighs about 75-80 pounds.

I would love to see an EVRV on the road.
__________________
Imagine sitting in your car at a stop light and only smelling....Fresh Air.

Don't pass deadly Gas, Drive an EV.
Reply With Quote
  #10  
Old 11-02-2008, 12:15 AM
LeTank's Avatar
LeTank LeTank is offline
Senior Member
 
Join Date: Jun 2008
Location: Rocky Mountains (Colorado)
Posts: 547
LeTank is an unknown quantity at this point
Default Re: Concieve the electric RV

Quote:
Originally Posted by TX_Dj View Post
I think a 144v system can produce far more than 360 ft/lbs torque. Heck, Crazyhorse makes over 1200 ft-lbs, and I think it's a 300-ish volt system (with gobs and gobs of amps). However, 300 HP = 223 kW... which can be generated by 111 volts @ 2000 amps... or 223 volts at 1000 amps, or 446 volts at 500 amps...

Actually, I found a 3 phase 150hp AC motor a few years ago through a Canadian electric motor company for $1,000 new. I think a 150 hp motor would easily run an RV down the road. It was rated at 3650 rpm.
I can't remember the name of the company since it was a while ago, but you could probably dig around and find something similar.

I believe its possible without spending a life savings on it.
__________________
Imagine sitting in your car at a stop light and only smelling....Fresh Air.

Don't pass deadly Gas, Drive an EV.
Reply With Quote
Reply

Share or Bookmark this

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

 
Support DIY Electric Car
Sponsors

All times are GMT -6. The time now is 11:13 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.

Ad Management by RedTyger