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Spitballing a car engine/multi-alternator large-ish generator

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Stainless:
Hi,

Most of us have seen the YouTube videos in which some enterprising soul attaches an alternator to a lawnmower engine or something similar, adds an inverter, and winds up with a decent (and loud) little 120 VAC generator. If you're like me, you have the remnants of one of those contraptions laying around in the garage.

While sipping scotch the other evening, I got to wondering if this could be viable on a larger scale. Say, a VW mechanical diesel engine with two or three alternators and a large (say, 2 kw continuous) inverter. 2 kw is the largest reputable 12 VDC feed voltage inverter that I could quickly find.

As a cocktail napkin sketch, let's assume that the inverter could pull up to 200 A at full load. If a person could feed more than 200 A back into the battery with alternators, would it work with any reliability? For the sake of argument, let's also assume that cooling the alternators and inverter isn't an issue.

I guess the biggest question for me is how a typical lead acid car battery would cope with that kind of continuous charge current and draw over a span of several hours (or days). Car audio guys have been piling on multiple alternators for decades, but they also tend to have numerous batteries in a bank. With maintenance and cost in mind, I'm wondering if one battery would do.

The upside that I can see here is that one wouldn't have to tightly control the engine RPMs as with a real 120 VAC generator attached to the engine. The VW 1.6 NA diesel probably produces 20 HP at 1000 RPMs, which might even be enough to spin the alternators, thus also saving money on fuel.

Anyone with any thoughts?

mab:
1st thought is 2kw isn't much load for the size of engine and diesels don't like being underworked.

2nd though is about the 200A; are you thinking of running 200a continuous from the battery then starting the gender to charge at 200a until charged and so on? If so your battery is going to get too hot fairly quickly. I suspect that even at higher volts (see next paragraph) you'd be better off just leaving the engine running to supply the power

3rd thought is go 24v - a lot of trucks are 24v so an alternator should be easy to come by, 1/2 the amps, better efficiency and bigger inverters available. 48v would be even better, but unless you're electronics savvy to mod an alt I'm not sure where you will find an alternator.

Mary B:
Why not pick up a generator head and skip the alternators, battery, and inverter? https://www.northerntool.com/shop/tools/product_8795_8795 probably be cheaper in the long run.

SparWeb:
Hi Stainless,
I'm afraid I'll have to echo the skepticism of the others.  It will be very inefficient. 
A 1.6L engine with a 1.5 HP load is basically running at idle and converting a lot of fuel into a small amount of electricity.
The same alternator could be run with a single piston 100cc motor for a lot less fuel. Of course, they build those already and they're pretty common.

electrondady1:
i hate the smell of diesel but a four cylinder  engine can do a lot more than just make  electricity. once up to temp it could heat your home. run hydraulic  systems. you can experiment with water injection. hydrogen injection . build a water jacket on the exhaust system to heat your home .   pump a bit of air into the exhaust system to reignite the exhaust gas and create a secondary burn chamber for hot water or steam. with a decent muffler and shroud you would barely hear it . not like some little Briggs and Stratton waking up the neighborhood.

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