Are you missing something here? Or maybe it's unclear what you are trying to do. Is your generator set up to put out about 60 volts for direct connection? Then just go through the tri-star. Why would you want to hook up another battery charger?
I use a high amperage alternator coupled to a honda I/C motor for low voltage charging. It has been figured out to be about the best way to go.
The Tristar is hooked up to the Solar Array, but it is also tunned to function as a diversion charge controller, i.e. diverting access power when preset SOC is achieved.[ Parent ]
You are going large I see. I would try to go with at least a 1800 RPM diesel and a small one. You are probably going to be faced with 6kw or 10kw to 20kw units. If you are just concerned about electric start battery charging then propane small 5-10hp engines would be far better for their fuel consumption than a large genset. But if you will use a large genset alongside charging such as doing the laundry and charging or running the well pump wile charging then I would probably go with the diesel. The fuel could also make a difference. If you get into bio-diesel? I know that direction inspires me. [ Parent ]
Lister engines are my favourite, already covered on this board. But I haven't got any access to those.
Thats the reason for hinking about a calvaged diesel engine of a Isuzu, as it would be probably running at around 4-6 hp at idle speed (Just a rough guess). And also parts are widely available.
Any makes or model that could also run on Biodiesel or vegoil, in addition to fulfilling these requirements?
(Hopefully that doen't change the core topic of this posting!)[ Parent ]
Good Luck and Happy Trails![ Parent ]
Not sure what you mean by over-expecting from automotive gas engines, but an automotive diesel engine's turn at around 600-800rpm when idle, and should be putting out around 4-5hp at least at that speed, and that as well at a superb fuel consumption, so I still find that an "automotive diesel engine conversion" a very attractive technical proposition, but again, no verdict could be made until after testing.
Thanks for your input.[ Parent ]
You did say it was remote. For a large system like you are describing get the diesel genset and the fuel delivery to with it and you will better off than most people in the city, if you enjoy it , but it will cost you quite a bit per kwh of diesel compared to the grid.[ Parent ]
The most efficient way is with a directly connected generator and this generator would need to be compatible with battery charging requirements. I couldn't see you finding such a thing commercially suitable for use at 48v.
"The alternator's output is stepped down using an iron-core AC Transformer, then run through a rectifier to output DC current to charge batteries."
That answers your own question, that is not direct connection, you have included a battery charger even if simple and home built. Once you go the battery charger route then your original question goes out the window. The new issue is what is the most efficient battery charger.
Beyond this the issue comes down to so many factors that I can't be bothered to wade through it. The high tech battery chargers are primarily designed for mains use and their main purpose is to look after the batteries. On mains they take what is needed to do it.
Running these things from generators alters the equation where you are looking at fuel economy load etc and in most cases they are expensive and far from ideal but they do give ideal charging characteristics.
Your transformer and rectifier if using a suitable transformer will be as good as the expensive high tech things but will not be as good as a direct 3 phase alternator rectified and set up for battery charging directly at 48v.
Single phase is dreadful for battery charging.
You will have so much advice that you will be no wiser in the end.
Flux[ Parent ]
Great explanation!
The reason for the inefficient iron core generator, mainly not to mess up with a readily available 220V single phase generator, by simply running a wire from it's output socket to a 1:4 or 1:3 transformer, so that when the resulting single phase AC passes through the rectifier, it gets within a reasonably efficient charging frame.
Yes, single phase & iron core transformer, both add to inefficiencies. So, what about directly connecting the high A/C line (220VAC) into the battery pack (after rectification)? Wouldn't that be comparatively efficient?
I know that a 3-phase PMA turning within the 50-60VDC Voltage frame is the most efficient way to go, but that would need some re-engineering work to an off-the-shelf generator.
It is preferable to either go for no retrofitting at all, or designing a completely custom-designed & built engine/generator.
To comply with the second route, any comments on the automotive diesel engine's retrofitting with the right PMA running at idle speed or just above idling speed! Wouldn't that be most efficient from both aspects i.e. the fuel consumption as well as battery charging? Also easier maintenance, widely available parts, cheaper, etc.....
Thanks. [ Parent ]
Late 1970's VW's and Audi's sometimes had a non-turbo 4-cyl diesel, later models had the "TDI" turbo-diesel.
I occasionally see early 1980's Mercedes diesels. 240D is the 4-cyl, 300D is the 5-cyl. When the automatic transmission wears out at ~250K miles, they are often crushed, even though the engine still runs fine. Uses gears instead of timing chain.
Keep and eye out for industrial equipment and military surplus auctions. I've seen water pumps, concrete cutters, etc, with a small diesel...[ Parent ]
Any idea on their hp rating @ idle speed?[ Parent ]
I've seen a few Isuzus around, but VW and Mercedes seem to be the most common 4-cyl's, here's a more complete list:
http://www.grassolean.com/index.html?textFile=dieselcars
If you're only idling, turbo-diesel's will run without the turbo, and if you get a "near-free" engine thats too big, a 4-cylinder can be run on two cylinders. I've just been collecting information for my retirement, so I haven't done this myself, but I have seen it done.
IMHO, a properly cared for Lister should last for decades, and is well worth the cost.[ Parent ]
