Riding mower charging device

[vantravlers7]

I tried asking this question in with a much larger post, so here's the smaller version.

   I want to be able to charge a 12 volt deep cycle battery.

   The system the battery is running is VERY small.  I have other means of charging if necessary, but I want to cut some teeth on RE stuff and building something that was a sucess (even if it was a SMALL sucess).

   I have a nearly comleted VAWT that I had planned on combining with a auto alternator/ generator.  As I reseached things, I found that the HP needed combined with high RPMs made this not a workable plan.

   I began asking questions about using a riding lawn mower's charging system, -I knew very little about one.  It finally took three trips to a local lawn mower repair shop to get even simple questions answered.

   Here's what I was told.  Most riding mowers use a magnet in the flywheel with a diode and a stator.  (Ok, so I am lost already, but if I can rob something of its charging sysem, I can likely make it work).  this type of system can't be expected to hard core charge a battery.  But it will, over time, charge one.  And it doesn't require a ton of HP OR the RPMs an auto alternator does.

   Other mowers use a generator/ starter.  This seems to be gear increased so it turns faster than the engine by quite a bit.

   Has anyone here DONE this already?  DOes this sound like a workable idea??  

   PS: This site is great, but really Im lost.  Everyone just seems to put links up instead of answering questions, and the technical talk is tough to even get a grip on.  Wish I would have taken some schooling on electrical ANYTHING.  But then again, taught myself to sculpt, mechanic, weld, build airplanes, etc.  I can get this... but Im about out of computer time to try and figure it all out!

[Volvo farmer]

Seems that many people have given you the advice to notuse a VAWT to provide a dependable, good source of energy for battery charging. Many have tried, very few have succeeded. The one guy who has succeeded has web pages that would require me to post links here, and that does not seem to be what you want.

You state you want to charge a 12V deep cycle battery. It's a really simple thing to do if you are willing to use solar panels or a HAWT. If you want to make charging a 12V battery really difficult and challenging, you have embarked on the right path, because hardly anyone has accomplished it with a VAWT and a purpose-built alternator, let alone with some scrap riding lawnmower charging system.

You claim you can weld. If I tell you I have a case of Bic lighters and a few coat hangers and I want to weld some 1/4" steel, what would you tell me?

[oztules]

The alternators on small combustion engines are usually embedded magnets on the internal wall of the flywheel. The magnets are comparatively weak, the coils/stator consisting of maybe 40 - 100 turns of wire on fairly basic iron cores (made from sheet silica steel punched out to hold the coils and follow the shape of the inner circumferance of the magnets in the flywheel)..... all in all nothing designed to make life easy for a budding RE project.... or for a slow turning VAWT.

The weak magnets combined with the low turns will require much higher rpm than you will be able to provide directly. At best rewinding the coils will get the rpm down, but at the expense of current. Vawts have not shown themselves to be very good at developing the power their owners expect, so maybe high voltage, high resistance coils will be enough to give you  very very limited satisfaction....but don't expect it to run anything useful......, and you will still have cogging just to rub salt into the wound....It's just.... well .. not a good idea.

The truth is yes it will work in theory, and you will get some measurable volts out of it.....but in practice, for the effort involved you will be very very disappointed.

When you complete your VAWT, give the dimensions and pics, and  someone may be able to provide answers on the best alternator style to be driven by it. It is highly unlikely that a mower flywheel and charging system will suit it.

Windstuffnow  ( http://www.windstuffnow.com/ ) seems to be the guru of vawts and alternators to try with them.

Have fun with it

.........oztules

[dinges]

"You claim you can weld. If I tell you I have a case of Bic lighters and a few coat hangers and I want to weld some 1/4" steel, what would you tell me?"

I would tell you that you haven't given us enough information. I.e., what colour are the Bic lighters ?

Peter.

[dinges]

On a slightly more helpful note...

There are 10.000 users on this board, churning out generators and windturbines at a steady rate. Just one of those (WindstuffEd) has built a working VAWT.

Now, have a look at this thread/contest by VolvoFarmer: http://www.fieldlines.com/story/2007/10/10/52711/090

If I were in a sarcastic mood I'd tell you to contact the winner of the contest for details of his winning project for you to copy. Alas. I'm not in a sarcastic mood. But hopefully you still get the point. No winner, not even a single contestant, as far as I know.

The only one who has actually made a working VAWT that puts out usable amounts of power is WindstuffEd (see link above by Oztules). Apart from his finished project for you to learn from, I fear you are on your own here. There are no other 'DanB/Hugh Piggots of VAWTs' as far as I know. You'd be pioneering the terrain, so to speak. Yes, I know this goes contrary to everything you read on the web about new, hugely succesful VAWTs, like the one installed by Jay Leno. But don't forget that on this board, no one is 1) trying to sell you something 2) trying to 'win' you for their cause 3) trying to fool you with misinformation (generally). Just a lot of open and direct information. And not always telling you the things you want to hear.

Personally I never understood this worrying about lack of suitable alternators for VAWTs. I have a few motorconversions lying around that would be suitable (cut-in at 75-100 RPM for a 12V system). Only downside is the iron-loss, but if you don't have anything else to generate, 10% iron loss would seem an attractive idea. Building an axial flux genny that cuts in at, say, 50 RPM, should be easy as pie too. Just keep adding turns of wire till the thing cuts in at 50, 10 or even 1 RPM.

In my humble opinion, the generator is actually the easiest part of any VAWT. The turbine being the hard part. Even when using plain (non-magnetically levitating) bearings.

Ok, I'd better stop now before Wdyasq comes hovering over my house with his flying combine.

Peter.

[electrondady1]

it is a curious thing,

so many people are attracted by the notion of a vawt.

yet so few make any head way at all in the successful completion of such a device.

[Norm]

I mow my lawn with an Ariens 8hp Briggs & Stratton it has a charging system but I spent

money and time for a battery and the starter

never seemed up to par unless the battery was

fully charged and the engine started on the first or second try....then too I noticed I had

to run the engine at about 1800-2000 for it to

charge....not to my liking to run this mower

faster than 900rpm nice and quiet at this speed.

   So anyhow I don't really need an electric starter....put on choke....a steady pull (not a

hard yank) will start it then quickly push the

choke off and its running.

   What I'm trying to tell you ....is .....

forget the idea....you'll be better off without

it...unless you have one laying around and want

to spend the time taking the camshaft out, the

connecting rod and piston out, gearing it up to

a 200 rpm VAWT @ about 1:15 ratio and just maybe

you'll get about 2 maybe 2.5 amp charging in a

15 mph wind.

[asheets]

If you really want to use the engine from that riding mower, forget using the onboard magneto.  Instead, take a look at http://www.qsl.net/ns8o/welcome.html for various ideas.

[asheets]

Or maybe I misunderstood the question.  Sorry.  I'll shut up now.

[Bruce S]

For the part of using the starter/ gen that comes on many riding mowers, motorcycles and even the 50cc mopeds. They will work, however, they are more for high RPMs and long duration running. They are more geared for starting the ICE (Internal Combustion Engine) then much of anything else. Once the motor is started it does switch into gen mode after the rpms are up to speed.

BUT you do can do it , and as you say it will charge over time, and if that's what you have a lot of, then go for it.

BUT if you have other options let us know what you have and see what can be come up with.

The guy at the repair shop was either really busy 'cause spring is coming or not interested in helping.

Back before gas was less than 0.49 cents/gal at full service, I worked at a small engine repair, the owner would talk to anybody to asked questions about them. Most all the instructors I learned from and helped teach with were the same way out going as helpful as possible, except just before spring when the mower that had been sitting outside in the weather didn't start :-)

Hope this helps

Bruce S

 

[vantravlers7]

Volvo farmer... would you knock it off?  Seriously, Im here to learn.  I really don't like being put down... even by some one MUCH more knowledgable than myself... over a simple set of questions that I simply DONT know the answers to.  But, never mind how I took it, your point is correct.  There might have been friendier ways to say it... or maybe you were being nice and I took it the wrong way.  

   Given enough time and energy, sure, I could make 1/4 inch metal out of bic lighters and coat hangers.  But would it be worth it?  Ok, so I see the point there, too

   And I did take the other advice offered previously to heart.  Solar panels ARE in my very near future.  The next big project after that is the water turbine, after some more research and measuring and figuring.  Solar is the easiest.

   But that still leaves the VAWT that I built.  Why not see if I could get SOMETHING off it.  A good introduction?  Or maybe a failure waiting to happen, by the sounds of things.  Evertime I walk by it... it looks like it SHOULD work... it wants to spin in the wind... besides, I have this thing for lost causes.  Ho hum... guess Ill shelf it for a while.    

   I wasnt trying ot be nasty about the "links" thing... sorry.

[Volvo farmer]

I'm sorry if I came across the wrong way. I tend to be a little abrasive in my personality sometimes. I was trying to help you achieve your goal and I agree I did not do it in the most diplomatic way possible.

Personally, I would scrap the VAWT, but maybe someone else can give you better advice, and be nicer about it. Sounds like you have a fun place set up there, hope you get your power situation sorted out as time goes by.

Best regards,

[wdyasq]

Sear Mr. Farmer,

I love these posts. One asks a question, gets the truth and shoots at the messenger.

It is always amazing to me how many 'are building a VAWT' and are going to 'get power off of it'.

The only reports I know of VAWTs are those sanctioned by the US Government and Windstuff Ed's. One reports success.

vantravlers7, the links to the reports on VAWTs and their design will be left for you to find. But, as you have a thing for lost causes, I doubt you will research your project.

Ron

[TomW]

Ron;

I sat on my hands rather than post about this yesterday.

If it were up to me we would institute a test to entry here and it would include an intelligence test.

I am simply sick and tired of new folks with this attitude. Too lazy to research too combative to say thanks when honest help is offered its going to stop or I will be fired one or the other.

Anyone bitching when someone responded honestly would lose their posting ability temporarily.

E nough off topic.

TomW

[vantravlers7]

Fair enough.  I didn't realize I opened a can of worms.  

   Volvofarmer... honestly thank you.  Your words ARE trully appreciated.

As for the followuppers..

  "Too lazy to research" (thats what I thought I was doing).  Geeze.

   Hell with it... heres my nasty post since I wont even have a computer in a week... Im going to go live off grid while some of you are sitting there doing little beside BYATCHING on the computer, and making "new" people feel like shlt.  I came here to learn, I get plssed on and its my fault?  HeIl, I dont know the FIRST thing about thses systems.  I do know a little bit about auto systems... enough to get me into trouble.  I came here to ask honest questions.  I came here because in a week, I wont have any way to GET informed... and it WILL be all trial and error.  I didn't come here expecting some completely off the wall system to work... I mean, hell even a lowly VAWT will in fact turn in the wind, it WAS mentioned in a thirty year old M.E.N. mag I found, and I thought that MAYBE someone had done something with such a system.  AND on another site, someone WAS working hard on getting a system to work.  Apparently, it won't work.  Fine.  I DID get some good answers to other questions, THIS post wasn't intended as to come across bitching, but I did get a harsh reply... I tried to be nice about it and take it with good humor, but I did feel a little insulted and I said as much... NICELY.

   But heres the windup: I'll be off grid, designing things that MIGHT and MIGHT not work.  Insulting my intelligence.... nice.  Stick it where the sun don't shine.

   You can keep THIS site, since your high born intelectuals visit it and anyone without an engineering degree can butt out.  I'm butting out.

[TomW]

7;

SIGH

FYI, contrary to common newcomer thinking, searching requires reading, not typing in questions for others to answer.

TomW