Basically what G1625S has described is what I was referring to. But instead of using the Listeroid 6-1 to power an AC head at a fixed RPM to power a batt charger, use a DC head (or 12/24volt car/truck/bus alternators) to directly power a battery DC bus. You can slow the engine down and still get DC at lower current, and speed it up when the load increases. Would work almost like the idle-back mode on a engine powered welder...
The benefit of variable engine speed = better economy, less hardware(ac/dc charger), longer life, less noise.
The downside is no 120vac 60hz directly from the genset if you become inverter-less .
(Although, you could just pull the serpentine belt off of the DC gen-head(s) and run it over to an aux AC gen-head if you needed AC output.)

The voltage and freq stability from a modern inverter is SO much better than that simple centrifugal governor on a Listeroid could ever produce.
I may be wrong, but I believe most all of those smaller chinese made ST generator heads that I've seen are the traditional self-regulating design, brush type, field-forcing regulated AC generators, in that the output voltage is proportional to the input RPM's. (no actual Automatic Voltage Regulator) As the load and the RPM's change, the voltage will drift with the RPM.
Sure puts the burden on the governor to hold the RPM's/voltage constant.

I've seen some really cool, high-rel, single cylinder diesel engined, emergency backup gensets for Telcom/celphone sites that output -48vdc directly to a DC bus. No AC, just DC. I think those high-rel generator heads are permanent magnet ALTERNATORS with built-in rectifiers(and regulators).

These new inverters are available in 12, 24 (32/36?) and 48vdc choices.
Military slurplus usually nets 24vdc stuff while commercial telco DC stuff is mostly-48vdc .
Man, if I could snag a surplus telco DC generator head, I know what DC voltage bus inverter choice I'd make!

K.

 

Just thought I'd bring this back TTT. I finally got my engines uncrated yesterday and got them both running. I'm hooked---they're so much cooler in person than on the computer screen! Who knows how many months they've sat idle and both started on the first compression hit. These things are just too cool I'll get some videos next time they run. I got a couple 1800 RPM 4-pole heads. They seem very solidly built and, I think, more than adequate for my meager cabin needs. The bearings are huge and turn over whisper quiet...and at 5kw they weigh 220 lbs! The engines are right at 900 lbs--the connecting rod is bigger than my arm--no wonder they run for ever, hehe. I'll snap some pics shortly. I'm excited now

 

Bet they're not as big as this one.

https://www.dieseltruckresource.com/...0&ppuser=19433

Those are still cool engines. Let us know how they work. I am looking to do something like that. The diesel generator I want is almost #7000.00. OUCH...

 

Some great reading material with lots of pics on the home made off grid listeroid generator sets. My $0.02 worth..

http://utterpower.com/

 

yup, that's the site that lit the fire for me. I bought my 5kw heads from George. Looking forward to producing 60 hz in the next several days

 

M-Benz 220D had oil bath filters so no problem there. I put a small 3" straight thru muffler on my TDI and it is very quiet. So I would try a glass pack type muffler with a long tailpipe and I bet you won't even hear the exhaust noise.

In MA I think the utilty co makes it impossible to sell your power back to them. I think the best you can do is stop the meter but you can't reverse it. They are a big Co. who doesn't want competition.

Great project by the way.

Dean

 

I could watch those engines thump along all day. The buried 55 gal drum sounds like a great idea for the exhaust. I found a new oil bath air cleaner on ebay cheap and used it on the ruggerini diesel genset I put together a couple years ago. It was from a larger model wisconsin gas engine.