Building a high power AC/DC generator system

[Rtqii]

http://theepicenter.com/tow123199.html

^^^ Decent site - he is engineering for gasoline engines, but offers some good info and has some parts for sale.

I will edit to add some more links for things like couplers as I come across them in today's research.

http://www.staffordmfg.com/pages/engdata.htm

^^^ Direct drive shaft couplers in mm-to-inch sizes suitable for many smaller generator applications.

http://www.lovejoy-inc.com/

^^^ Lovejoy couplers

[chug]

When I get my 6/1 set up I was planning on running a ST on one flywheel and a auto alternator on the other flywheel for charging batteries.
Are some of you doing this?

[mobile_bob]

yes i am

if i might suggest

use a hd big truck alternator such as

http://www.prestolite.com/pgs_products/specs.php?item_detail_id=24319&item_series_id=94&refresh=1156314564
these can be had from your local hd truck dealers when they have the on sale for as low as 150 bucks of so.


controlled by a marine controller such as

http://www.balmar.net/page67-ars5.html
this optimizes the charging regime to maximise charging and minimize engine run time.

bob g

[chug]

Thanks,Bob
I wonder about a military surplus alternator?  Ther'e mad tough I think.  I know you can sometimes buy a box of them on auctions cheap, but the ones in the box are probably a hunk of crap thats why they are in the box.

[aqmxv]

The big mil-spec alternators are indeed very stout.  Look for the "upgrade" model for something like an M35, commonly seen on the M109 shop vans.

Downsides:  They're 24 volt.  Which means that you may have some trouble finding a regulator with an optimized charging algorithm.

[chug]

Thanks,
I didn't relize they were 24 volt.  I think I might stick to civilian issue unless someone has a good idea or experience on how to real in 24 volt on a 12 volt system.  I'm not a electrical engineer by any stretch.  I don't don't even know what a charging algorithm is.  I'm a wood truss designer by trade.  I do know what algebra is, however.

[hotater]

How does the  'power/drag/economy/cost/life'  figures come out in this scenario----

1)  Run an AC genhead for house power and a DC head to charge batteries for downtime.  Figure in charge controllers and generator heads and mounts and belts things unique to this system.

2)  Run an AC charge controller from the AC genhead and forget the DC part of it?

I'm missing something??

[binnie]

Could be an Inverter.....expensive.....binnie

[GIII]

We anguished about whether to go with AC or DC and how to implement each to minimize losses.  We finally decided to run common 12v truck alternators with outputs up to 200 amps. Flywheel v-belts and small diameter pulleys on the alternators get the speed up for max output.  Large AGM batteries were available at no cost and the bank has about 4000 amp-hr capacity.

Everything that could be run on 12v was converted; lights, fans, pumps, and things of that nature.  Refrigeration power is through an inverter as is power for electric cooking devices, including the microwave.  There are no heavy loads like air conditioning, water heating, welders, and clothes dryers run from batteries, but they can be run from the 2-71 when necessary.

Going with DC lets us run for about 4-5 days in non-conserve mode without charging the batteries.  The Lister can be run at a ‘more pleasant’ speed at night without upsetting the frequency of the AC.  There is also an alternator on the Atlas to charge the batteries while under way; it would be difficult to get AC at 60 cycles from the varying speeds of the Atlas.

This is probably not the ‘best’ way but it has proved to be a very viable way for us and all the parts we used are available at truck stops from coast to coast, even inverters can be had for a few dollars.

George

[chug]

What are large AGM batteries?

[hotater]

Chug---

Acid Glass Matting,  I think.  One of the best ways to find things quick is ebay to get specifics then Google to really learn about them.
  I just want to know how  he got those good batteries free!?

[DaveW]

Adsorbed Glass mat.  Great batteries, and expensive.  I have three sets of 48 volt Absolyte IIP batteries, and love them.  No watering schedule, don't outgas, store or use upright or on their side, no equalizing schedule.  Down side - expensive, doesn't like deep cycle work, needs temperature monitoring during recharge, and has a tricky recharge pattern.  But if you treat them right they will last for 20+ years.  I have had them in service for 6, 7 and 8 years and at worse have lost about 2% of capacity.

[Doug]

There is a new sinter lead process being developed for EVs I've been reading about. Not as good as NiCad or NMh but it shows promiss as a better energy density and cheaper than the glass. Won't be common for a some time yet....

Doug

[GIII]

We got the batteries from an outfit that has several large UPS systems and they change the batteries on a regular cycle of about 2 years.  Their operation is critical enough that even though the batteries would probably go for 6-10 years, the cost of being 'down' is not worth the cost odf new bateries.  The outfit that sells the batteries has to deal with them as hazardous waste so is happy to sort them as to good, ok and bad if we can take all away.  I'll bet that by checking with ups battery distributors or large users, a deal can be had near you too!
George

[WestCoastPat]

I've been charging my home off grid system exclusively with the standard Chevy Delco alternator with no internal regulator, (no external regulator either...NONE) but a heavy variable load resistor to adjust amps, direct to a battery bank of 12- L16's for over 12 years. I've run different small engines over the years.  I run my CNC shop machines with the same setup but a (real) 9hp Honda. I don't have a meter on the 9 hp rig yet, so I don't know how many amps it's putting out.

I get a solid 55 amps for the house system. I'm running a 16hp Honda knock off, with a 7" sheave.  I run the engine slow as possible to put a good load on in, yet run the alt at 55 amps. 55 amps is the max I've been able to get out of these inexpensive alts dependably.

The best bang for the buck has been Napa alts at $36 each with a 3 year warranty. They are chinese rebuilt or maybe new. They look new, and out last any of the lower end auto supply cheap alts.  The Napa and 16hp chicom honda has ran excellent for 4 years now.

I have 2 lister JKson 6/1 kits I need to put together, and wondered how they would perform for this setup.

I'm going to machine some aluminum serpentine belt sheave pulleys for these setups, and start doing tests for fuel consumption, amp output and engine/alt longevity with rpm ratio tests, etc. For me direct to DC has been a cost effective off grid generator to keep running.

I never saw the need to run a big AC generator, that starts out with DC, then converts it to AC to be sent to your Grid inverter, that intern converts it back to DC for the battery bank.  I believe it's hard on the inverter as well. I've gotten a solid 10 years out of my L16s, and I'm still using my first set in the shop.

Another observation is when running machines with the AC gen and inverter charging, any startup surge really tasks my 8KW ac generator and Trace SW4000 inverter. Even a tablesaw start up. Running the alternator DC gen direct to the battery bank can handle pure surge power effortlessly.

I've been sold on it for a long time. Cheap reliable off grid power.