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bredlo · 06-09-2005, 05:12 PM

Has anyone installed a wind generator on their setup in order to trickle charge their batteries while traveling? I'd like to build one (or buy) that looks like those little weather stations on nice yachts... the ones that look like 4 little halves of ping pong balls. That way I could even mount it underneath the tongue and get a great breeze going through it while driving down the highway.

I did a cursory search for this, but found nothing. I'm really interested in using whatever I can to keep the batteries topped off every day as we go place to place.

markdoane · 06-09-2005, 05:17 PM

There are lots of windmills available for sailboats, but they are larger than what you have in mind. They vary from 18" to 48"

I don't know if the 'ping pong' ball design is very effective. They are very good at measuring speed, not generating power.

overlander63 · 06-09-2005, 05:34 PM

You would most likely be better off with a solar panel, than a wind powered generator. I can just see a low-hanging branch, or a big gust of wind, tweaking the generator, rendering it useless.

gklott · 06-09-2005, 05:41 PM

We looked at it, but we've decided to go with solar. The ones you mention, the horizontal half cup ones, are pretty expensive - they have the word MARINE in front of the name. That increases the prices by a factor or 10.

73/gus

bryanl · 06-09-2005, 06:23 PM

The best way to charge your batteries when going down the road is with the alternator you already have. Even with the standard isolator and wiring you will get more current at higher efficiency than any wind generator going down the highway. If you want better charging, install heavier guage wiring or a buck/boost controller.

The size of a wind generator needed to charge batteries while in camp is probably going to be a meter or 3 feet in diameter or so. If you have breezes you can depend upon these can be a nice way to go but can be a bit noisy. They also need to be set up and taken down and stowed for transit so convenience can be a factor.

bobechs · 06-09-2005, 06:55 PM

Yes Bryan, but what if the TV itself is wind powered? I don't necessarily mean a sailing rig for main power, although that would be something to handle. What if you used a windmill generator to make electricity to power an electric tow vehicle? Then you could just pipe over some of the spare elecricity to charge up the house battery!

I don't think you are really getting into the spirit of this. Oh, and it would be Organic, too.

markdoane · 06-10-2005, 03:34 AM

i'm planning to buy a Hybrid electric powered tow vehicle, as soon as they come out.

Then I'm gonna replace the axle on my '59 Tradewind with the rear axle from a late 70's Chevy pickup. I'll mount a 400 amp alternator on the axle differential. Then I'll run 4/0 welding cable to my 1200 ah golf cart batteries, and use those to power the tow vehicle.

If I can get 100% efficiency, theoretically I will never need to buy gas. Very organic!

bobechs · 06-10-2005, 06:58 AM

Mark;

Good idea, but you will have to be careful that the differential turns in the proper direction to drive the alternator. Otherwise the alternator will become a motor and with the drive axle now in the trailer there will be articulation problems at the hitch!

Oh, it makes my head hurt to think about it. I'm just going to get an organic smoothie and rest for a while.

overlander63 · 06-10-2005, 07:34 AM

Quote:

Originally Posted by bobechs

Mark;

Good idea, but you will have to be careful that the differential turns in the proper direction to drive the alternator. Otherwise the alternator will become a motor and with the drive axle now in the trailer there will be articulation problems at the hitch!

Oh, it makes my head hurt to think about it. I'm just going to get an organic smoothie and rest for a while.

The older Chrysler alternators didn't care which way they turned. I installed a pair on a twin-engine boat when a replacement would have cost more than I paid for the boat. For those non-nautical folks, most twin-engine boats have one engine that rotates opposite of the other engine, to offset each others' torque.
If you don't want a setup like that, you can always cover the trailer with solar panels, you can charge the tow vehicle's batteries overnight. As long as you park under a bright street light...

And yes, I know the quoted post was done tongue-in-chique, as is mine.

markdoane · 06-10-2005, 07:40 AM

Bob,

I hadn't thought of that! I can unhitch at the campground entrance and let the trailer drive itself backwards into it's parking spot.

Time for my organic cappacino.

bryanl · 06-10-2005, 09:36 AM

Oh, I didn't realize I was in the perpetual motion room. ;-)

But it does get me thinking about the sway problem a lot of folks seem to experience. This makes me think of fish. Perhaps we could add some cogs on the trailer wheels or something so that, as it swayed back and forth, it would work its way down the road. Then you could attach a lever on the hitch so the back and forth motion would power a generator in the tow vehicle. Of course, the Hensley and Pullrite folks would be left out of this unique propulsion and energy system.

As far as sails, have you noted that those are already in use? A lot of semi's have these things on the roof to improve airflow. With just a bit of modification they could probably also be used to provide some forward thrust.

bredlo · 06-10-2005, 10:36 AM

Alright, smarties!

I'm still going to look into it, though Bryan had a good point. I read somewhere that a car's alternator tops off the car battery in about the first 20 minutes of driving, which means that it's doing nothing for the rest of the time. I'd like to use that to recharge the Airstream batteries, which I'll look into.

By the way, I never said I was gonna mount a giant windmill on the roof - just a small, homemade one a foot or two wide that would sit under the tongue and top off the batteries as it spun while going down the highway. The blades would be homemade (out of ABS?) and be easily replaceable if they were damaged by rocks or road debris.

Man, some of you guys really think this renewable energy stuff is as silly as pyramid-crystal power! Don't be too quick to laugh it off!

bobechs · 06-10-2005, 11:06 AM

Brad,

Don't get me wrong, I don't think renewable energy concepts are silly in themselves. Each solution, traditional or 'organic' has to stand on its own, based on what it can actually accomplish.

Bryan's answer to you was sober and on point: why put a fan on your car to spin a generator when you are already using your car to spin a generator? In other words, the organic solution is just, as they say, 'a bag on the side' (the classic definition of a kludge.) And that is without even taking into account the (perhaps negligible )effect hanging a windmill out in the slipstream has on the total energy usage of the system, cost of the extra equipment, weight, maintenance, effect on overall reliability of the electrics, and so on.

That's when we got a little goofy in the back of the bus.

Btw, RVs are already set up to pull recharge power for the house battery from the TV. That is what the blue wire in the 7-way connector is intended for (IIRcolorsC). As to whether yours is properly wired to do so, I can't say. But check it out, it's the easy way to do what you want.

And no shame for asking about another way of doing things. But don't expect an excessive level of solemnity when a squirrel gets loose around here.

bredlo · 06-10-2005, 11:13 AM

Bobechs - no harm done. I know how we can get around here... this is nothin'. I do have a deep interest in not polluting my way across America, and leaving as light of a trail as possible, so that's where the interest comes from. Solar seems bulky and expensive, and frankly ugly. The alternator thing is a great "alternative" (yuk, yuk) so I'll look into how I'd rewire that into my '63.

overlander63 · 06-10-2005, 12:24 PM

Quote:

Originally Posted by bredlo

The alternator thing is a great "alternative" (yuk, yuk) so I'll look into how I'd rewire that into my '63.

Now that we've all yucked it up over the alternator thing, remember that until about 20 years ago, that is exactly how the railroads powered their lights and ventilation systems on cabooses, and some passenger cars. Usually, a pair of belts ran from a pulley outside the wheel, or inside on the axle, to a mounted generator which charged batteries under the car. I can think of too many reasons it wouldn't be practical, but if you really, really, REALLY wanted to do it that way, I am sure a way could be found to do it. For example, a pulley welded onto a brake drum, turning a belt, with an automatic tensioner, going into the wheelwell to an alternator, which would charge the battery.

markdoane · 06-10-2005, 03:16 PM

Quote:

Originally Posted by overlander63

For example, a pulley welded onto a brake drum, turning a belt, with an automatic tensioner, going into the wheelwell to an alternator, which would charge the battery.

It doesn't need to be that complicated. All you need to do is tack weld an Alnico magnet to your brake drum. Each time the magnet passes through the field of your brake magnet coil it will generate a current. Run the current through a rectifier and a diode back to the battery. Voila!

bobechs · 06-10-2005, 03:55 PM

That's right- just basic electromagnetic theory. A magnet moving in a coil generates voltage and voltage yields up current.

Bryan wanted to put trailer sway to work and so you could do something similar there. Mount a magnet on an armature on the TV side and put a coil around around it from the trailer hitch side. Shape the pieces so that they are a sector of the circle described by the pivot at the ball. Every time the pivot works, wah-lah! pure organic electricity.

Oh! Oh! and I just thought of this- the energy captured will be taken from the kinetic energy of the sway. This will act as a sway damper too!

Towdaddy · 06-10-2005, 07:14 PM

Since there seems to be interest in "green" energy here, I suggest that you try the "12 Volt Side of Life" web site. This is an interesting site for those who want to generate their own electricity or live off the grid for a week at a time in their RV. I don't have the link handy, just google the name and it comes up.

till · 06-11-2005, 07:46 AM

I thought that Airstreams were wired to have the tow vehicles alternator charce the battery in the coach???????

In my manual it shows that pin 2 is the chaarge wire for the choach battery.
I know that the pin numbers have changed since 1967, but there are still 7 pins....
I see that your coach is a 1963, but upgrading the wireing should be easy enough.

overlander63 · 06-11-2005, 09:23 AM

Quote:

Originally Posted by till

I thought that Airstreams were wired to have the tow vehicles alternator charce the battery in the coach???????

In my manual it shows that pin 2 is the chaarge wire for the choach battery.
I know that the pin numbers have changed since 1967, but there are still 7 pins....
I see that your coach is a 1963, but upgrading the wireing should be easy enough.

Tedd, 1963 was the last year the coaches came without a factory Univolt, or plug-in charger, for the 12v system. If you wanted to use the 12v lights and fans, etc, you would have to wait until you were hooked up to the tow vehicle before your house battery would start being recharged. If you were planning on, say, being on batteries (boondocking) one day, and then being on 110v the next, if you didn't drive quite a while to recharge the battery, you would be starting day 3 with a partial charge.
He is trying to figure out a way to charge his battery without being plugged into 110v, and buying an Intellipower. We all just kind of went off on a tangent with off-the-wall ideas for a bit.