Friday, December 18, 2009

Engine fun

Engine funNow here's something I think is really fun.

I love things that work, whatever they are.

Usually, the bigger the better, though this tiny Honda engine is an exception.

It's an amazing 25cc four stroke engine, weighing almost nothing, but producing one horespower (0.72 kW).

The possibilities are endless.

My plan for this little beauty is to connect it up to an alternator and produce 24V to charge my battery bank when the wind's not blowing.

By producing 24V directly from an alternator, I maximise the efficiency of producing power.

This engine should be able to top up my battery bank using a fraction of the fuel any of my other mains generators would do.


  1. Anonymous4:08 PM

    I thought you already had a 24V generator on your auxiliary engine. Isn't that good for charging your batteries, or did I miss something?

    If you want super efficiency I would have thought maybe a small air-cooled diesel would be the ticket. That Honda looks cool and all, but better suited to situations where portability, power-to-weight and multi-orientation operation are important. For a stationary battery charger, a small diesel would be more efficient,last longer and be more forgiving about what you swill into its tank.

  2. Anonymous2:21 AM

    Hi Tim,
    Just a bit of arithmetic: 720W/28Volts=25Amps. So not much bang for the buck and that's assuming 100% alternator efficiency, so actually a bit less. And also, that's with the little bugger screaming at 7000 rpm. I think i'm with mr. anonymous above.
    But it is a cute little engine. Maybe it could be adapted for rust busting.
    Cheers, David

  3. Hi Tim Happy Chtistmas to you! I`m curently using a 1/4 horse mains motor to drive a modified alternator (fot whatever reason) and I get about 35/45 volts "ac" and the motor slows to a stop. so maybe you will have to accept a slow charge using your system? I would be very interested to know just what revs tou can get that honda up to under load and at what amperage the motor stalls.
    Take care and have a great and productive new year, Regards Rob

  4. Hi Anonymous

    I have a 24V AC and 110 V DC generators on my auxiliary.

    It's the main engine has a 24V alternator on it.

    In any event, the auxiliary and my deck diesel generators are noisy beasts.

    I believe I can silence that little Honda to whisper quiet.



  5. Hi David

    The 25amps, or even less, is perfectly fine.

    The objective here is relatively low power to augment the wind generator power.



  6. Hi Rob

    There are quite a few things I'm due to learn about this whole lot.

    A concern is just how to ensure the amps the generator produces is carefully controlled, so as not to tax the motor unduly.