Portable micro electric generators

sailaway21 · #1 (**permalink**) 12-30-2006

I have been contemplating doing some cruising on Lake Michigan in my 21' Cal in the future. I've been considering various methods of energy supply. I have an outboard motor and run it as little as possible; three times last summer. Solar panels do not impress me for energy output for deck space consumed and they are pricey. I like the idea of the towed generators but they do not really begin to shine until 5-6 knots, I've only found one under a grand, and of course you have to be moving to generate the juice. Realistically I'm only going to carry two batteries due to space limitations. I'm adding an autopilot and am smart enough to know that I will probably under estimate my actual amp usage. So I really can't get around the point that I have to charge those bricks somehow and relying on periodic shore power seems pollyannaish if not poor seamanship. Although I am of Dutch extraction I'm not against spending some money if I can see how it will meet my needs and be a long-term solution.
I got thinking about generators and how small does anybody actually make one. As usual, if one can get out of the "boat" and "marine" mind-set it opens up a lot of options. What I found was a Yamaha built gasoline powered 900 watt portable inverter generator. Now the good part: It weighs 28 lbs and measures 18"x15"x9" and emits 47-57db. It'll run on 7/10 of a gallon of gas for 12 hours at 25% load. The inverter function is apparently to give one a regulated supply of DC voltage. I could use the AC output to run my "shore side" battery charger though, and thus taper my charging.
Ok. Shoot me down!

I found it at www.electricgeneratorsdirect.com

sharkbait · #2 (**permalink**) 12-30-2006

checkout the honda eu1000

camaraderie · #3 (**permalink**) 12-30-2006

sailaway...I really like the concept of the Yamaha but I read the pdf manual and concluded that it is really underpowered for charging duties as it only puts out 7.5 AC amps and 8 DC. It will take a LONG time running to put a charge back in your batteries at those rates and using an external charger will probably just overload the unit as it calls for more watts than can be delivered. Also...the rated 900 watts is only into a steady state load and drops off severely if motorized stuff is connected. I don't think it would be of much use on a boat and I think the little Honda's would be a better choice.
AC Output
Rated Voltage V 120
Rated frequency Hz 60
Rated current A 7.5
Rated Output VA 900
Safty Device: Type Electronic
DC Output
Rated voltage V 12
Rated current A 8
Safety Device: Type DC protector

ianhlnd · #4 (**permalink**) 12-30-2006

a penny's worth,

The Honda EU1000 is a great little generator, I've used mine for 8 years with no problems at all. Little noise - within 50 ft can't hear it - use it for everything, although watch your power consumption, even though it's a 1kw, you'll only get 750 out of it. Get the optional battery charging cables. Sometimes a charger will pull more than it can generate if you run it through the boats electrical system.

sailaway21 · #5 (**permalink**) 12-30-2006

Honda seems to be rated exactly the same as the Yamaha and 2-300 dollars more expensive, although the Honda name might be worth it. My battery charger requires 535 watts input and using it alone would seem to be within the capabilities of either unit. Charging off the inverter would certainly reduce the load further although at the expense of a longer run time. Really wouldn't have much to use it on other than battery charging (and about 45 other things I can think of if I thought to keep it in the back of my truck!)
I suspect I'm missing your point Cam. I know-not unusual!

camaraderie · #6 (**permalink**) 12-30-2006

sailaway:
"My battery charger requires 535 watts input" ...means about 4-5 amps which the Yamaha is capable of. The question is what is the OUTPUT of your battery charger with that input. At 100% efficiency 535 AC watts = about 45 DC amps which probably means you'll get something like 30 AMPS. This may be enough for your battery bank...kinda depends on your dailiy use on a 21 footer. For most cruisers, with refrigeration and autopilots etc. this would not be enough.

For something utilitarian that can come in handy in a lot of situations...it looks great. I have a friend with a Pacific Seacraft 37 that bought the honda1000 and is really unhappy with it since the charging output is quite restricted and he wishes he had spent the $$ for the 2000W unit and the higher amperage for his much larger battery bank...so...it all depends on your need. I really liked the DC output feature on the Yamaha but i wonder why they were so restrictive on the output... guess it would have raised the price too much to beef that up.

pigslo · #7 (**permalink**) 12-30-2006

I don't see in your post the mention of a wind generator? Even if price is an obstacle there are plans online to build one out of a car alternator. Perhaps a 2 pronged approach of a wind generator and a small bank of solar cells.
pigslo

sailaway21 · #8 (**permalink**) 12-30-2006

Blade length? Use underway? Have you got a site-I got the alternator. Tnx-Pigs.

pigslo · #9 (**permalink**) 12-30-2006

http://www.motherearthnews.com/Alter...Wind_Generator
This one talks about abig one but has info on blades.

pigslo · #10 (**permalink**) 12-30-2006

http://theepicenter.com/tow082099.html This one uses a car alternator and lawnmower to get an inexpensive gas powered.