Brad Ideas - Hybrid RVs, more RV notes - Comments

http://99mpg.com/Projectcars/

Mike — Sun, 10 Oct 2010 21:52:47 -0700

http://99mpg.com/Projectcars/TheBestHybridmix/

Here is an undersized example of a guy that added an electric motor and an extra wheel to push his first generation Insight assisting the gas engine when needed. I think this could easily be scaled to handle a motorhome.

I have been in combat robotics for years. The dc brushed motor controls I used are full h-bridges. That means that have regen built in. I took my combat robot and converted it to a self balancing scooter, aka Segway. When I tilt the scooter backwards to slow down, it regens current back into the pack automatically as a design of the motor controller, to slow down the scooter. For RV use, a joystick could be added to the dash to control the current going to the motor or push the current back into the batteries.

One comment I want to make about driving, is that the world is not flat. If you have ever owned any hybrid vehicle the instrumentation shows clearly when you are getting regen or when you are getting assist. RV's may travel long distances but the use of gravity to push power back into a pack or use power to help push the RV up a hill will have a serious benefit. Granted, RV's mostly weigh a lot, but after 30 years of driving large automobiles, most of the gas wasted is from just getting the vehicle moving from a stop. The one place an electric motor rules is at zero mph/rpm.

I have some OSMC motor controls that can handle 169 amps peak, but with heat sinks and a fan can handle lot of current for a long time. I think the OSMC and almost any electric motor geared down from about 4:1 to maybe 10:1 or so will give an RV a nice increase in starting torque from a stop. If the RV is used for long trips, then the regen or assist feature could be used the entire time while driving. I have not looked, but will be looking soon, at the bottom of as many RV's as I can fine to see how much room is available for holding a wheel and it's brackets and motor assist assembly. The big brother to the OSMC is the MC-1. The MC-1 handles 450 amps at 42v. Both are out of production, but are not that hard to find used. Any h-bridge based motor controlled with have regen as a side benefit.

Mike

PS I am going to the San Jose Fair grounds to the RV show probably Monday Oct 11th, 2010, if anyone wants to discuss this. Email me if you want to connect. mikep_95133 at yahoo.com.

Interesting life choice. How do you deal with your mail?

MM, NY — Sun, 11 Jul 2010 08:13:24 -0700

Ws wondering how you deal with mail and any other "residence-based" things?

Thanks for any insight.

drippy RV showers

pete condit — Wed, 26 May 2010 04:09:08 -0700

So THAT'S why they leak.

Thanks for enlightening me, Richard.

hybrid RV

pete condit — Wed, 26 May 2010 03:42:35 -0700

Some interesting thoughts on hybrid RVs.

BTW, better than 12 mpg can be had. My 21 ft toyota Sunrader will get 15-17 with it's trusty 22RE engine. A new benz diesel powered C class can get over twenty, but, they are pricey. It's for sale, BTW. I just bought another toy motorhome.

As for electric or hybrid powering of large vehicles, don't hold your breath for it.

Electric or hybrid power makes sense on a commuter bus which lives in an urban environment at low speeds and with of brake use and no need for extended ranges. It makes sense pretty much for any sized urban vehicle with similar needs. RVs and large trucks don't live here. They generally live on the open road and eat up the miles in big gulps, big rig trucks in particular. The electric side of a hybrid drivetrain would pretty much just be an expensive heavy passenger in such a case. Take a look at mileage between a VW TDI and Toyota Prius. The prius wins around town, but, not on the interstate.

The diesel electric drivetrain analogy is a flawed one as well.

There is one reason this drivetrain is used. The reason is not efficiency. Burning fuel to turn an engine to turn a generator to make electricity to turn a motor is not efficient.

The reason is nobody has figured out how to make a big enough clutch yet. Freight trains weigh bazillions of pounds. Getting a bazillion pounds rolling is tricky. There is not a transmission yet made that can do it efficiently other than a really, really big electric motor which, unlike ICE engines, develops max torque at 0 rpm. ICEs tend to make 0 torque at 0 rpms. Big rigs are big, but, not so big that we haven't figured out how to build a conventional tranny and clutch to handle it.

So, until manhattan becomes a popular RV destination, I doubt we'll see hybrid RVs.

Pete

RV of the future

Anthony — Mon, 24 May 2010 20:39:57 -0700

I've been having similar thoughts about a revolutionary RV design. I love to design and fabricate machines. I was speaking to my son yesterday about finding investors and developing the next generation RV. Even in a bad economy people will buy an RV that's revolutionary. It appears that RV'ing is ever gaining in popularity. What we need is an extremely lightweight aluminum chassis and a revolutionary lightweight diesel engine. The Corvette ZO6 has an aluminum frame that's shipped to the factory and placed on the assembly line with it's steel cousins. The engine is titanium and aluminum. Diesel engine blocks and heads however must be something other than aluminum. It appears that diesel engine builders have relied on heavy castings for so long there's no lightweight alternative. Maybe a there's a super alloy yet to be developed which would allow builders to cut the engine weight in half. A 6 cylinder Cummins weighs 1100 lbs.

Aerodynamics is another area which needs attention. I see the modern RV as a large brick designed to consume large quantities of fuel. A lower center of gravity is needed during travel, then a roof that can be raised when parked is the solution. Air turbulence over the roof and under the chassis must be eliminated. Adjustable and flexible air dams are needed. Seeing that RV's travel long distances without stopping, regeneration from braking is a waist of time. Excess heat from exhaust gasses can be used to drive sterling engines; these coupled with electric motors can drive A/C compressors. The motors can generate power when the A/C's not in service. Every new automobile in the world should have it's compressor in the trunk area using electric and sterling motors to power it. No extra fuel required to cool the interior. Big oil, tobacco, banks, and auto makers are filthy whores in bed together; they conspire to rob the people of every dollar they have.

Turbine engines are better suited, and are the most efficient prime movers for electrical power generation. This could also be used to power the RV itself instead of a diesel engine. The exterior should have a Kynar finish; their oldest coating is over 50 years old and maintains an 80% reflectivity. Reflecting and refracting sunlight keeps the interior cool and helps maintain the beauty of the finish. The Kynar could be cross-linked with the gel coat resin when making the outer wall panels; white being the most efficient of colors. This future RV will get at 30-50 mpg via it's turbine electric drive train, main engine run at low rpms drives generator, lightweight lithium ion cells used to overcome inertia when stopped and to power the unit when parked. Aerodynamic, lightweight chassis, and fuselage with a 50 year fade resistant finish. Anything I missed?

Hybrid RV

complex web development — Mon, 19 Apr 2010 01:54:00 -0700

Hybrid engines lack giddie up, and some truck hybros do have horse power, but lack in necessary torque to manage backweight or load hauls. RV's weigh so much, i wonder if it is feasible in the next 10 years to develop them.

As for the being interested in such a product, my wife and I will purchase something like this in the future (after we retire in 20 years or so) but we would rent one much sooner if it where available. I do not find the initial price of such a vehicle an issue because they tend to be quite costly anyways and with the price of fuel being what it is the difference will not be much when doing a lot of traveling like we will.

As for other energy saving devices there are thousands on the market that would help reduce weight and energy consumption. One other device that maybe included is a wind power generator, which tend to be more efficent than solar for its size. where as solar could be used while traveling for powering AC and possibly charging batteries if needed.

Thanks.

I recall a story about a guy

Rufus13 — Sat, 17 Apr 2010 01:25:00 -0700

I recall a story about a guy with a Dodge Ram PU with Cummins TD who was off-grid and hauled a half a bed of deep cycle batteries with him to work. in the 90 minutes each way, they charged enough to power his trailer when he got back home. There were some details like a belt-driven 120V alternator and charge controllers, high-current disconnects, securing the batteries, plugging the truck in at work to keep charging, etc.

Batteries work best when you need a little bit of power over a long period or a medium amount of power briefly and not too often. Charging shouldn't happen too fast either if you want to get a long life from the battery. Most deep cycle batteries are rated at 1/20 discharge, meaning that discharge is over 20 hours. Charging ought to be less than at a 1/10 rate. Unfortunately, people live on a planet with only 5 good hours of solar power to charge their battery and 19 hours to use it. Something has to give more and it is usually an internal combustion engine turning a generator an hour before dusk to try to get a decent charge in an under-sized battery bank.

Personal virtues of endurance and being cold while sitting in the dark only goes so far. Everyone gets wool hats and will learn night vision scanning techniques from the US Army Ranger Handbook. Ha.

Cheers.

Parked big Class-A solar cell holder

Rufus13 — Sat, 17 Apr 2010 01:03:36 -0700

Some cities are not at all friendly to DIY house improvements or safe and NEC+ electrical changes that are not "conventional", BUT zoning and codes that apply to a house for solar-electric/co-generation/backup power don't apply when done to/on/inside an RV parked on a pad.

As noted in an above post, Class-A really-big RV's are getting much less expensive as the economy gets worse and depreciation kicks in. Many of these rigs are in good shape with low miles, but take half a paycheck to tank up for a 10 hour drive.

Thanks for the link to the incinerating toilet. !800W is not a huge deal if a generator is running. I'd never pull that much power from a battery bank,even if it was possible, if I could help it. A toilet like that in a remote location that allowed much less water consumption and no sewer connection would pay for itself quickly or even make an impossible thing work. I don't like military-style field sanitation over trenches, or any of the "humanure" concepts. In a basement or bunker, it's golden.

Getting a completely legal and safe power disconnect installed in a house after the meter and before the main breaker panel is not a problem (even less of an issue if doing an upgrade to the panel). The official explanation is to allow the house to run from an auxiliary generator without back-feeding the grid during a power interruption, which is true.

The reality is that with quite a bit of care about loads, a house can run on a 3KW inverter. Not an electric clothes dryer, 240v welder, electric baseboard heat, electric hot water heat and the rest of the modern all-electric house, but the low-load stuff like lighting and computers as well as a central heating ignition and fan.

The RV is going to be the aux generator. All of the complexity of the solar panel install/charge controller/inverter/battery bank/RV gas generator that would normally cause a city inspector to demand an engineering review (to CHA) will be none of his business and not his jurisdiction because it's attached to a "vehicle", even if the RV sits on stands (tires are expensive!) for 2 decades and is not tagged for road travel.

If it's a 36'+ model, there's probably plenty of room to make an office, art studio, or guest room in addition to power generation. Isn't this what most people do with their parked RV's?

In my brief searches, I have not seen solar panel brackets that allow tilting the panels to get a little more output from the sun angle. Lots of flat roof mount systems available for RV's, though. I'd want to drop the panels flat against the roof before moving the rig, and forgetting to do this is why no manufacturer wants to sell hinged brackets like this.

People who accept Fed/State subsidy of their house grid-tied PV installs may find themselves legally restricted from removing the panels. If I was running a subsidy program, I would require repayment plus interest if the house is sold without the complete working system paid for by the taxpayer. Of course, it's a give-away program for now.

Another neat thing about putting the valuable parts of a PV/inverter system on a vehicle is that it can be moved to your next house. Unplug the RV from the house power system, pull out and show the next owner how neat it is to be able to run a generator safely away from the house (noise/exhaust, etc.) and give the key to the disconnect box.

Cheers.

Maybe it’s your term

Anonymous — Wed, 14 Apr 2010 14:22:39 -0700

Maybe it’s your term "hybrid", seems to me that most hybrid are designed for city traffic...using the cars brakes to put energy back into the car and of course designed small with small engines. From what I've seen hybrid do not offer many savings on the open highway where the RV plays, other than what is addressed by being small with well designed small engines. Electric Diesel, now you’re talking (VERY BIG BUCKS)…Electric something anyway. Where are the energy cells I saw on “Sixty Minutes” the other day that turn hydrocarbon fuel into electricity? Make an RV that runs on that and you will change life as we know it.

hybid rv

Anonymous — Tue, 06 Apr 2010 21:19:10 -0700

i thought of the idea that a big semi truck would deliver a load of batteries if their were lots of them and the truck had a big electric motor with a wire to the batteries would it run

Hybrid RV

Ty — Mon, 05 Oct 2009 19:22:24 -0700

Try a Gulf Stream Montaj.They're green and have luxury amenities of any other Class A RV.They're supposed to be very livable.The gas engine kicks in when the hybrid engine runs out of power.They go about 25 mpg on gas and can be driven like a RoadTrek,SUV,or a Class C RV . Go to http://www.gulfstreamcoach.com/index.htm.

super efficient luxury airstream

Scott — Wed, 30 Sep 2009 12:58:38 -0700

ram air wind generator. Hi I have also thought about that idea. Its sounds like a very god idea as you have access to 50-60 mph winds which can generate lots of electricity. I have started the process of starting from scratch with a new 30 foot airstream classic shell and am going to retrofit completely with upscale and efficient appliances. I am toying with all electric with solar and maybe even dc air conditioners . Lots to think about but I know it can be done and be renewable and very comfortable. Keep thinking. From experience camping is where I have got most of my ideas. Good luck. Scott

RV

Anonymous — Mon, 21 Sep 2009 14:34:59 -0700

Its all cost vs ROI, the RV builders have no incentive to vastly improve the motorhome designs and functions. The people who are spending $500k plus want all the technology but there is a limit to the actual cost vs perceived value to the customer, would I pay an extra $40k for a hybrid drive system that gets 10% better mileage,no. Like all vehicles RV's lose a tremendous amount of their value at the time of purchase, so where is the pay back in spending extra at time of purchase. I have a class A that is 5 years old and has lost most of its value even though the miles are low and the condition is very good.
The market for RV's is very low right now and those that are trying to sell are really hurting because of low resale value, its all supply and demand. Lowering operating cost and cost of ownership will bring more people into the market, but as long as the cost of RV ownership and use remains high its going to be a hard time selling them.
Fuel prices effect everyone, even the high end class A owners.

SINKS

Anonymous — Wed, 12 Aug 2009 07:39:25 -0700

There are health laws requiring a toilet to have a sink nearby, but not used for food preparation. So, 2 sinks are necessary, one for food the other for toilet use.

the extra wind drag would

Scotty — Tue, 11 Aug 2009 04:23:19 -0700

the extra wind drag would increase load on the engine. It would be more effichent / lightweight to simply put a second or bigger alternater on the engine. plus that whay it would still generate power at idel

Hybrid RVs, more RV notes

brad — Tue, 13 Sep 2005 18:43:06 -0700

Every time I take an RV trip (ie. each Burning Man) I come up with more observations. The biggest one is that it cost $360 in gasoline to go from the bay area to the black rock desert, about 800 miles. And that’s at a price still well below world price. The RV owner said he was planning to get out of the business, people no longer want to pay the gas price.

So why is it taking so long to produce a hybrid RV? Hybrid cars are great of course, but trucks and RVs are what really suck gas and need the improved efficiency. And they have the room for larger and more unusual engine configurations. Most of all, RVs also mostly come with expensive generators and batteries, and a hybrid RV would of course have a super duper power plant and batteries and inverters, presuming the engine was efficient at lower revs. The Hybrid RV’s power plant could also be a backup generator when parked at the non-moving home. Probably make the most sense with diesel fuel, or as I have suggested before, even the highly efficient stirling engine. (Stirlings are big, and take time to warm up, but an RV with batteries is fine with this.)

Every RV’s shower has this hose based showerhead with an on-off dial with a slight leak. Our camp built a much nicer shower using a standard kitchen sprayer. A kitchen sprayer with a lock-on would be much better and would make it easier to conserve water by letting you pulse water where you need it when rinsing.

Cleaning the RV, especially when back from the desert, is hard. RV renters charge fat cleaning deposits and fees. Why doesn’t some company that hires out housekeepers do an RV service. You could come to them. Drive in, and a team of 5 attacks your RV, cleaning it in minutes. Do it at a car wash to also handle the outside if needed. Espcially after Burning Man there’s a business here.

I’ve said these before: Paper towel racks, built-in soap dispensers, inverters, flourescent lights. Why aren’t these everywhere in the RV world, instead of being rare?

Stabilizers jacks are great, but how about something simpler, some way to lock the springs or shocks (of course with an interlock to prevent starting the vehicle!) And while slide-outs are great, why do we never see flip out beds the way pop-top campers have, or a pop-up on the cab-over bed? (Most RVs don’t have any spare wall space except in the master bedroom, which does limit the flip-out bed concept. You also almost never see murphy beds.) Flip-out beds don’t take away your dinette or couch as do the extra beds commonly found. And how about a seat belt design for use on the beds for safe sleeping while driving? You can do this now but it doesn’t seem super safe.