DC-only generator/chargers

[SternWake]

Sounds like an impressive system. The large frame alternator is Key, If one will not fit look into the Balmar AT Hairpin wound series.

http://www.pbase.com/mainecruising/automotive_alternators_vs_deep_cycle_batteries

In fact, look at all the electrically related sub topics withing that site, it is a goldmine of good info which will serve you well.

 

[John61CT]

Yes great stuff, thanks for the link. The boating world really has a wealth of good info, result of much more stringent use cases, compared to most RVers. The way I want to van-live is actually quite similar to a cruising liveaboard sailboat.

 

[Mobilesport]

https://www.google.com/url?sa=t&sou...ggaMAA&usg=AFQjCNGCQPdjSeOAT2wMvuLcsfSzHeJYhQ

 

[Mobilesport]

I found this at
Sailboatwners.com 


this HTML class. Value is ://
http://purplesagetradingpost.com/sumner/macgregor/outside-13.html

 

[John61CT]

nice

having your own machine shop, priceless!

 

[666JTK666]

Instead of going nuts with a v6 automotive engine to drive my large frame alternators I just came upon this and it looks like I would fit the bill nicely.
http://www.harborfreight.com/22-hp-708cc-v-twin-vertical-shaft-gas-engine-epa-62879.html

 

[eDJ_]

I finally found this Mother Earth News Magazine article.   I read about this a number of years ago from a pile of these old back issues a friend had. 

It may have some application to this discussion.  Here's an abstract of it

The people who did this lived a mile out in the boondocks and had a house trailer to live in out there.
Back then 12 volt DC Fluorescent lights from Boats were the ticket.   Before LED's were so common as they are today.  The Trailer was rigged with a Vehicle radio/tape and sound system.  (I think they may have found some 12 vdc appliances as well. 

What they did for domestic water, hot water,  etc was amazing to me.  They got an old Ford Pinto engine and mounted some specialized alternator that produced 240 VAC to run the water well pump.  The 12 vdc,  generator charged a bank of batteries they had, and an old 500 gallon Propane tank was insulated and converted to a water tank for cooling of the Pinto motor.   A Domestic water coil was installed inside of it.

On a scaffold near the trailer the water tank on it was filed by the well pump so that gravity supplied the water to the Trailer. Part of the water was diverted through the domestic water coil in the water tank so hot and cold water were available on demand.   So there was light at night, radio for news, weather reports, and music for entertainment, hot and cold water always available etc.

You can read the article here:

http://www.motherearthnews.com/homesteading-and-livestock/off-grid-power-zmaz80jazraw

 

[John61CT]

Instead of going nuts with a v6 automotive engine to drive my large frame alternators I just came upon this and it looks like I would fit the bill nicely.
http://www.harborfreight.com/22-hp-708cc-v-twin-vertical-shaft-gas-engine-epa-62879.html

More than I would personally want to be carrying around with me in (or on) my van

 

[John61CT]

yes, lots of my neighbors rigged up that sort of setup, pretty common in outback Oz. One guy actually ran his off of an old Volkswagen with the wheel removed, had a pulley bolted to the rear axle of the bug

 

[SternWake]

You tube has lots of the basic recipe for a DIY 12v generator.  Mounting surface for engine, mounting system for alternator.  Some mounting options look very complicated, others more elegant and simple.

https://www.youtube.com/results?search_query=DIY+12v+generator

What are the engines they use in the motorized bicycles?  I know they could not  turn much of an alternator, but Dual purpose is my thinking.  Power a bike and/or an alternator.

I'd be good with 40 amps and adjustable voltage.

 

[grummy]

I did not see any references to what your actual amperage requirements/desires are, or the exact space it must fit. If an off the shelf car alternator can provide enough amperage, I'd certainly opt to build this DC generator because frankly, no one makes such a thing (they perhaps should, but do not). I'd opt for a 14-16HP vertical shaft twin to power it. Vertical shaft because they are less expensive new, often really cheap used, and somewhat fits the end goal of compact better than a horizontal shaft engine.

The alternator could be mounted on either the top with the addition of an Aux PTO shaft on the flywheel side, or on the output side below depending on space restrictions. The twin will provide a smooth operation and a properly sized alternator amperage output to HP, driven by a toothed belt might allow you to obtain adequate amperage at 1800 rpm rather than wide open (3600). The engine would also provide an additional built in alternator, usually 15 amps designed to charge a lawn mowers battery, but some had options to provide 20 amp.

Too, you get electric start, so this means you can remote start it if you configure a remote choke (or use an injected model). Beyond remote start, you can use a programmable relay from Factorymation.com (similar to a PLC but easier to program), to automate the entire charging operation, starting the engine at precise voltage points, and running until charged to your desires, be they voltage levels or via timed event.

The twin can be made to run rather quietly compared to a single (just stand next to a modern John Deere or Cub Cadet when running), and you could go the extra length to obtain quiet by running a liquid cooled Kawasaki where the cooling system really does not add much to the engines dimension.

I was going to do this... then got lazy and just bought the damn Honda EU2000.

 

[John61CT]

Great info here. The limiting factor is everything needs to be portable, if not up on the roof rack then on a hitch cargo carrier.

I agree the physical mounting and drive coupling are the biggest challenges, along with good customizable temp and charge cycle control.

At this point, seeing how far I can go with my van engine as prime mover, investigation custom HO alternators and maximizing output from low RPM, figuring out the pulley ratio / belt torque issues seems the better approach.

If I need to scale down the size of the TV and run a propane fridge, that would be worth avoiding building, lugging around running and maintaining a separate genset.

 

[John61CT]

You tube has lots of the basic recipe for a DIY 12v generator.  Mounting surface for engine, mounting system for alternator.  Some mounting options look very complicated, others more elegant and simple.

https://www.youtube.com/results?search_query=DIY+12v+generator

What are the engines they use in the motorized bicycles?  I know they could not  turn much of an alternator, but Dual purpose is my thinking.  Power a bike and/or an alternator.

I'd be good with 40 amps and adjustable voltage.

My impression is that 40 actually produced continuous Amps (as opposed to short-term peak fantasy Alt ratings) would require a full HP.

Of actual continuous power, so a 2 - 2.5 HP rated engine.

And larger, if noise pitch/volume are an issue and you want to gear up, you need good torque at low RPM. Robin-Subaru or Honda 5-7HP is what I was looking at for a rated 150+A, actually producing maybe a hundred at "high idling".

Run about 40-50 lbs I think.

Modern bike motors are electric anyways these days aren't they?

 

[SternWake]

Modern bike motors are electric anyways these days aren't they?

For my own uses, i'd rather have a motorized bicycle that i could attach an Alternator to, even if 40 amps is the max rating, and not likely to be sustained.

https://www.gasbike.net/collections/engine-kits/products/212cc-death-row-bike-engine-kit-4-stroke

I'll likely never do either.  My Knee does not like the pedaling motion.  In watching those videos, i was kind of considering how compact a gas powered DC generator could be made, and the motorized bike motors struck me as a possibility.

I heard a 4 stroke motorized bike  the other day, and I was struck by how quiet it was.  None of the engines in those U tube videos strike me as quiet.  Quite Annoying really with that piston slap/metal on metal sound.  I'd rather listen to my 318 Idle for ~50 amps, but that is a gas sucking 50 amps.

From the noise and dual purpose standpoint, in my prospective personal uses, I'd still be looking to power my 40 amp charger on a Honda 1000 inverter generator as then I could put a window shaker AC in the window if I had to move to Florida or something.

With LEad Acid, one can fairly quickly get them to 80% with a high amp source run for a relatively short period of time, but that 80 to 100% requires declining amps constant voltage in the mid 14's and 5 + more hours to get to that 100% range which is so important for their performance/ lifespan.

With Lifepo4 the tapering does not really happen until closer to 100%, and they do not require getting to 100% and are better off kept under that level.

A big quiet motor and a large frame alternator externally regulated alternators would be the ticket for a Large Lifepo4 bank.  One could make one of those sound boxes for it and pump some cooler air into it via a small 12v radiator fan for further sound reduction.  I'd think getting the pulley sizes optimized for amp production in the engine's sweet spot when under max load from depleted batteries would require some trial and error.

It is certainly a neat strategy for powering relatively large loads off grid

 

[eDJ_]

Just a FYI here.

I was just watching DW News TV (Deusche Welle Germany)  and they are explaining how Solar energy is so on the rise that the cost of Solar is now on the level of Coal & Gas energy.   Still many countries are lagging in investing in Solar and getting behind renewable energy.

But this may be good news for Van people who would want roof mounted Solar and to use a rack of batteries so that they are all 12 vdc.   Those who aren't so mechanically inclined may avoid a genset all together or use a small inverter generator for their needs. 

This isn't the same report that just aired,  but explains some of it.

http://www.dw.com/en/solar-energy-on-the-rise/a-18185806

http://www.dw.com/en/germany-charges-ahead-as-solar-power-booms/a-16383531

 

[John61CT]

Lifepo4 is how much more expensive than lead? I guess in comparing, if Lifepo4 can be drawn down lower and not fully recharged without so drastically reducing lifespan, you'd need to downrate the Lifepo4 AH against larger Rated capacity lead batteries.

Your point about only the fast Bulk phase requires big amps, combines very relevantly with the idea of small quiet motors.

It would be nice if silent zero-fuel Solar alone could take over Absorption and Float (Trickle), but many places and times there just isn't enough sun.

So maybe the tiny motor's worth researching. I suspect the bicycle ones are too low powered, and/or expensive running 100+ hours/month.

But the GX100 drives the EU2000i, if that could drive a stock (very cheap!) alt at low rpms maybe 1HP would be enough.

Make sure it's quiet, make a small self-contained frame, that might just be the ticket to bring a big lead bank from 80% up to 100%, letting me shut down the van engine much sooner.

 

[LeeRevell]

Germany is far ahead of the USA on solar use. Upwards of 40% of their urban energy is produced by solar. This is one rare area where we could look to them for inspiration.

 

[blars]

Lifepo4 is how much more expensive than lead? I guess in comparing, if Lifepo4 can be drawn down lower and not fully recharged without so drastically reducing lifespan, you'd need to downrate the Lifepo4 AH against larger Rated capacity lead batteries.

See my latest blog article: http://techno-viking.com/posts/battery-price/
Per rated amp-hour, LiFePO4 are about twice high-end AGM. Per usable amp-hour, system cost is about the same.

 

[Mobilesport]

http://www.alten-dc.com/gasoline-powered-dc-generators.html
Here's a link to a company that sales gasoline  powered  dc generators

 

[eDJ_]

I was watching the NBC Nightly news Tuesday evening of this week I believe and they reported on a device created by a Greek Engineer/inventor, Petros Zografos,  that makes electrical energy from water. 

The story got so much traffic on Youtube that the video crashed.   The next day NBC nightly news ran a "second day story" on this and explained the amount of interest it gained in the last 24 hours from the report.

I'm reserved in my opinion about it.   Watch for yourself.

Youtube




But if this got loose,  even if only in plans where one could build their own, it could be a power plant for an RV without a doubt.  

We hear all kinds of stories about this stuff,  cars that can get 150 mpg etc and it is easy to dismiss any break through technologies.  

But every now and then glimpses of these things get loose.

VW XL1 260 mpg Diesel/Electric hybrid Car on Youtube





Zougla's water powered motor scooter




This may only be a different type of generator than what we are used to.



I hope how soon these videos are available in English language.