I'm sure this has been covered before. But I realized that when my engine is running, and my bus alternator is turning, I have plenty of power from my inverter and battery bank. I've run my AC while driving and after a few hours of driving, my batteries were fully charged, and my AC and other loads have been consistent.
So, I got to thinking, If I had a small motor (gas/diesel) that only needed to turn an alternator, I'd have all the generator I need.
Thoughts?
And if you used an electric motor to turn the alternator, it could run for free!
Oh well, back to reality. I would think that you could do what you suggest, although there certainly could be logistic issues to overcome. But I don't know why it would be better than having a store bought generator.
Yes, this all makes sense, but like Lin mentioned, you are basically creating a generator.
If you have 300W alternator, how many HP gas engine would you need to rotate the armature at a relatively constant velocity for long periods of time and how much fuel would it consume? One of the smallest generator is the Honda and puts out 1000W and runs very quite on very little fuel and is very quiet. How can you beat that?
Maybe you can find some way to disable 7 of the 8 cylinders on your engine and shut the fuel off to those cylinders and then you can burn diesel which you already have then you only have to change the oil in one engine, not two. :-)
Back when we had our ACF Brill, the previous owner had an approx 5 to 8 up engine hooked to an automobile alternator. He had a small panel with a volt and ammeter and a rheostat connected to the field? circuit. You started up the engine, then turned up the rheostat for desired output. Full up should would make that engine work. Used it with no issues as long as we had that coach. In those days, couldn't afford any better.
Tikvah
A small engine running an alternator has been bounced around here in the past. The consensus has been that it is not energy efficient.
--Geoff
For me, there is little difference between an engine running an alternator that supplies an inverter (your typical Honda/Yamaha inverter generator) and an engine running an alternator that runs an inverter a la carte. I was going to use a small automotive gas engine and a pair of large 24 volt alternators, and my existing Magnum 4024 and existing battery bank. The main difficulty was finding a way to govern the engine speed vs load.
Brian
If you are looking at doing something with a low investment, you could try one of the Harbor freight units. They are reasonable in price when on sale and will give a better idea of what ultimately works for your situation.
A typical generator consists of an engine that drives a "generator" that produces AC electricity. that electricity goes to my battery charger, and converts the power to DC and charges my batteries. A replacement generator head is expensive but the system works great.
Another solution, is that same engine, driving an "24v alternator" that directly charges the batteries. Bus alternators are also expensive, but not as expensive as a generator head.
Engine speed isn't as critical, an alternator produces 24V regardless of speed, but produces more amperage with higher speed (of course using a typical voyage regulator).
Just seems really easy and affordable.
Quote from: Tikvah on April 29, 2017, 04:32:22 AM
A typical generator consists of an engine that drives a "generator" that produces AC electricity. that electricity goes to my battery charger, and converts the power to DC and charges my batteries. A replacement generator head is expensive but the system works great.
Another solution, is that same engine, driving an "24v alternator" that directly charges the batteries. Bus alternators are also expensive, but not as expensive as a generator head.
Engine speed isn't as critical, an alternator produces 24V regardless of speed, but produces more amperage with higher speed (of course using a typical voyage regulator).
Just seems really easy and affordable.
I don't know but I assume that's the principal that the little inverter gensets work on. The challenge for a homebrew setup is doing it for the low cost that you can now purchase a store bought unit for. I just picked up a 3100 watt Champion inverter genset with remote start, brand spanking new for a measly 1200 Canuck bux. That's under $1000 in real dollars and did I mention, it has remote start? Its also a clean professional looking unit that I can throw in the back of the truck or roll around the shop on its own wheels. Its gonna be pretty hard to top that with a homebrew unit. And I don't know about you but my homebrew units tend to end up looking like homebrew units.
Bottom line with generating electricity, you need a power source. That can be a Diesel engine, gasoline/propane engine, the sun, water power, nuclear power, etc that turns an alternator. Many of us have the big Delco 50DN direct drive alternators on our engines. 12V 300amps at 14.1 running volts or 4,230 watts. 24V 270amps at 28.2 running volts or 7,614 volts. Then run these through an inverter.
Whether it be a separate engine, or running from the big engine, you'll be burning fuel to create energy. You will burn less drawing the power from the big engine while driving, as compared to running your generator going down the road. Nothing is for free.
Good Luck, TomC
Quote from: bobofthenorth on April 29, 2017, 09:51:12 AM... And I don't know about you but my homebrew units tend to end up looking like homebrew units.
Yes, there is that but (IMO), the bigger issue is control of the output power. The newer Honda units (and their competition) are known for putting out power that more consistent, efficient, and "cleaner" than the power coming down the electric company grid in a lot of places. Even a very good inverter (and very good = $$$), is limited to how good it can be by the quality of "juice" coming from the home-brew alternator. Will it probably work OK? Yes, probably. Will is be more likely to act up just when you need it to work right? Yes, probably.
IMO again, paying $900 (real $$$, but who's gloating) for a unit with engineered power control is going to be the way to go in almost all instances.
Those little inverter generators are great for tent camping, but I need 8kw for the bus.
--Geoff
Dave
Ah but there is something free. Wind power. How about some kind of turbin type fan that would work going down the road and it would turn a belt to your second 24 volt Alternator. Put it inside the side back doors to the engine compartment with an air scoop pushing the air through the fan. Have a regulator on it to adjust the output , done.... Just thinking outside the box!.... ;D
Dave5Cs
I believe myself to have lost my ability to communicate with writing.
I only intended to speculate on the potential of a simple engine and bus alternator for a simple, cost effective solution as a generator. I have no idea how much amperage my 24V alternator produces, but it's more than enough for all my needs.
Yes, I realize all engines use some kind of fuel. But, while burning that fuel, would it make sense to simply power my eight golf-cart batteries instead of producing AC power? The battery storage is already there. The Inverter is already there. Alternators are $200+ ???
An engine???
A little 1000W Chinese generator for $1000 won't run my battery charger, much less an air conditioner. So, let us not make comparisons there. I would be happy with about 3OOO watts.
Remember, I installed a mini-splits before mini-splits were cool (pun intended). I've also done stupid stuff - not to be unearthed here.
Okay, so let us start over, is this another stupid idea, or might this be ranked with the genius of the mini-split?
Found it... This is not something totally new. It can be done. New question - how much hp to run a bus alternator at full load? And, where can I get a quiet diesel engine?
https://www.youtube.com/watch?v=lzIf6ifjwN8 (https://www.youtube.com/watch?v=lzIf6ifjwN8)
Quote from: Tikvah on April 29, 2017, 01:33:03 PM
Found it... This is not something totally new. It can be done. New question - how much hp to run a bus alternator at full load? And, where can I get a quiet diesel engine?
https://www.youtube.com/watch?v=lzIf6ifjwN8 (https://www.youtube.com/watch?v=lzIf6ifjwN8)
quiet...not gonna happen
hp. for an alternator:
a 100 amp alternator would be about 1400 watts output , or about 2hp, figure 50% efficiency that would suggest you need 4hp at maximum load.
google answered these ??'s
double for 2 alts
and double again for 170 amp....
You say you have eight golfcart batteries. That's exactly what I will have when I buy my real house batteries (I'm presently using some old 8D starting batteries to test everything, but they're ready for scrapping now). 2000 watts of solar panels will very nicely charge eight GC2s at about a 13% charge rate, the maximum for FLA batteries. 1000 watts of solar will charge them at half that rate. PV now is well less than a dollar a watt for grid-tie panels, and a decent charge controller or two costs less than an inverter generator. With solar you will be charging your house batteries all the time the sun is out, from dawn to dusk each day, whether you're driving or parked. Silent, exhaust-free, maintenance-free, breakdown-free, essentially free use after the initial purchase, completely automatic, minimum 25 year life, shades your roof from the sun - what's not to like?
Just an idea . . .
John
What's not to like? The entire roof covered with solar panels.
--Geoff
Here's some generators to peruse
http://www.harborfreight.com/engines-generators/gas-engine-generators.html (http://www.harborfreight.com/engines-generators/gas-engine-generators.html)
Their are a lot of good things to say about solar panels. What concerns me most though would be having to park in direct sunlight when it's already warm weather. That would mean I would need to run the generator for the AC, while if I was parked in the shade, I might get by with opening the windows. It sort of depends on where you are and what season. Here in the desert, I think in terms of heat though. It would be nice to have solar panels that do well in shade.
Mount them on a trailer, park it out in the sun, and run power cable to coach that is parked in the shade.
You may look at military surplus, find a genset with a bad head and good engine. The 5 and 10 kW military genset are usually Onan air cooled diesel that run at 1800 rpm. I can see where you are going with your idea. The only drawback that I can see, is that you will be reliant on your inverters all the time. This will require rather hearty inverters to run motor loads. The motor starting currents are hard on inverters, and if it's not well sized, cooled and of good quality I would not be sure how long it would last. Just some thoughts to throw into the mix. Believe me I am all for non conventional set-ups and trying new things. If you decide to go this route, keep us updated. I have not completely settled on my systems yet, so I am still keeping my options open.
Jeff LoGiudice
Tampa, Fl.
1986 TMC 102A3
1999 Reliabilt 6V92TA
Allison HT740
I have looked for a quiet small engine and have not found one ??? if you rent a small honda 3000 watt or a 7000 watt inverter genne from a rent all it is unreal how quite these things run . under 60 db's that is regular conversations ??
I have the honda 7000 watt genne it is amazing and if I did not have the 12 k diesel power tech in a hush box ( not near as quiet as the honda ) all set up with the remote start . and all the work two change it out + the problem of the GAS engine of the honda I would change it , but then I would have to install a gas tank for it . so that is not going to happen
I had the 3100 watt Champion inverter genset and it worked great but used a lot more gas then the honda and was way way loader then the honda but again the price was 1/3 of the honda
the honda I have now ( and added a WIRED REMOTE START that worked every time )
http://www.campingworld.com/shopping/item/honda-eu7000is-generator-with-electronic-fuel-injection/81958 (http://www.campingworld.com/shopping/item/honda-eu7000is-generator-with-electronic-fuel-injection/81958)
why can't I get this in a diesel genne ??????
my 2 cents worth
dave
Quote from: Tikvah on April 29, 2017, 01:33:03 PM
Found it... This is not something totally new. It can be done. New question - how much hp to run a bus alternator at full load? And, where can I get a quiet diesel engine?
https://www.youtube.com/watch?v=lzIf6ifjwN8 (https://www.youtube.com/watch?v=lzIf6ifjwN8)
Nobody ever said it couldn't be done but I repeat - when you get all done you'll have something that looks like I built it.
As for the quiet small diesel - good luck - someone has recommended the air cooled Onans - I can assure you that isn't the answer if you're looking for quiet. I've got one of them and when I start it up you can hear it 3 counties over. Its a great engine - damn near bullet proof but quiet wasn't invented when they built that engine.
No to belabour the point but I exercised my little Champion yesterday afternoon - 1200 meager Canuck-bux complete with remote start and it all comes in a package 2 x 2 x 2 feet. 3100 watts in a neat compact frame on wheels. Good luck matching that for under $1000 US in a homebrew package.
Bob, the Champion is a good generator,I bought a 3000w from Costco when we were building the restaurant in Phoenix and ran it 12 to 15 hrs a day for 6 months all I did was change the oil every 50 hrs it never missed a lick.LOL the H/F wasn't so good it lasted about 1 month and after 2 replacements they gave me money back
A HP is 746 watts, zero losses. So if you said 2 hp per 1,000 watts of eventual output, you would be close. My thought was to be able to run my 4024 at up to 4KW I would need around 8 hp. My idea was to get an engine that could produce 8 - 10 hp at around 1200 rpm, big flywheel, two 200 amp 24 volt alternators and just let it idle. I had a friend who was going to do this with a fuel injected computer controlled engine out of a wrecked honda he had, he said he could set the idle speed to whatever he wanted with his diagnostic programmer and it would run at that speed up until it was overloaded, self governing.
I've heard of people using Volkswagen's small TDI diesel engines for home-made generators. Apparently they run them at a fast idle, just fast enough to prevent coking and glazing problems, and they can run for hours on a single gallon of fuel with a moderate load.
John
Quote from: bevans6 on April 30, 2017, 09:52:54 AM
My thought was to be able to run my 4024 at up to 4KW I would need around 8 hp. My idea was to get an engine that could produce 8 - 10 hp at around 1200 rpm, big flywheel, two 200 amp 24 volt alternators and just let it idle.
Maybe a Lister or Listeroid, or even a Bolinder? Imagine firing up a Bolinder in a campground - now that would attract some serious attention!
John
Quote from: Iceni John on April 30, 2017, 12:59:26 PM
Maybe a Lister or Listeroid, or even a Bolinder? Imagine firing up a Bolinder in a campground - now that would attract some serious attention!
John
yes..none of those will get you run out of town...
Quote from: Iceni John on April 30, 2017, 12:41:01 PMI've heard of people using Volkswagen's small TDI diesel engines for home-made generators. Apparently they run them at a fast idle, just fast enough to prevent coking and glazing problems, and they can run for hours on a single gallon of fuel with a moderate load.
John
I have seen a factory-made generator based around one of these. It was made by VW to be a mechanical engine (no ECM, etc.) - otherwise the TDI was externally very much like my car engine. I never saw it run - the guy who owned it let it sit outside for a few years and everything on it rusted up and many parts fell off.
Or:
You could just buy a Honda EU3000is and have a tiny, compact, stupidly quiet, unbelievably efficient power source.
Just a nod to our Facebook conversation Dave :)
I do love my twin hondas. They are amazing.
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Quote from: Scott & Heather on May 03, 2017, 05:51:16 PM
Or:
You could just buy a Honda EU3000is and have a tiny, compact, stupidly quiet, unbelievably efficient power source.
Just a nod to our Facebook conversation Dave :)
I do love my twin hondas. They are amazing.
Sent from my iPhone using Tapatalk
For the money you spent for two eu3000is and the connections you could have bought an 8kw 1800 RPM diesel genset and made a sound box. Permanently mounted with inside controls.
--Geoff
You could "go green"
https://www.youtube.com/watch?v=e4-hZ5UEH_w (https://www.youtube.com/watch?v=e4-hZ5UEH_w)
Quote from: Jim Eh. on May 03, 2017, 06:50:02 PMYou could "go green"
https://www.youtube.com/watch?v=e4-hZ5UEH_w (https://www.youtube.com/watch?v=e4-hZ5UEH_w)
I found Kw numbers for energy consumed by riding a bicycle up a fairly slight hill. I figured if you're really making about 42 Kw/h, meaning that with battery efficiency losses (of 10 - 12%), it would take you about 9 hours to charge a typical laptop, or you could just barely keep up with a 40 watt refrigerator light bulb.
Not very useful ...
I was checking around and an Onan 8kw was running over $9000. I bought my twins on sale from a Honda dealer for $3200 for the pair. Most of the time I only run one, but if I have a bigger load for a short time I fire up the second one. 21 hours on 3gal of fuel....I made the right decision for us. Someday, we will replace them with a diesel just for the fuel simplicity of siphoning off the main tank, but for now, these are as reliable as anything and I don't regret buying them for a moment.
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I paid $3295 for my diesel Isuzu 3 clyinder water cooled 1800 rpm generator. No electronics. This was a brand new unit with an English Stamford-Newage 8kW head. I have it in a sound box. Inside controls, and it runs everything in my bus I need at once. I wouldn't touch an overpriced Onan with a 10 ft stick, although I have repaired them. They are way over priced. So while $3200 was a good price ($4,000 regular price) for the Honda's plus the connector kit, can you run them on the road and run two roof airs? I can run three 15btu roof airs with my generator. I also have 1024 hrs on my genset. I just did an oil analysis on it (Rotella 15w-40 oil) with 150 hours on the oil and the results came back perfect.
So keep your eye out for a good diesel generator, not a new Onan, and you will be even happier than you are with the Honda's.
--Geoff
Where did you get a "diesel Isuzu 3 clyinder water cooled" for only $3200?
You had to be around 20 years ago. I posted the information on this board back then. It was a special deal a generator company had going. The company is called TUBAN but they are not doing much these days.
--Geoff
LOL... twenty years ago we were selling 6v92 v730 or 8v71 v730 take outs for $1200. Fob Gulfport. Or complete RTS's for $3000.. twenty years makes a lot of difference...tdw
Yes, twenty years ago MC-9s were going for $30,000. Now they go for around $10,000.
--Geoff