generators

[mikemacdonald]

Thinking of a small generator for our Snowgoose, need >1Kw to help out the batteries, Honda look good but expensive. Any ideas please?

[theguerns]

We have a honda 1kw on board and use it alot as we have washing machine 150watts and spindryer 240watts tv dvd sterio and central heating also we use the main 240v battery charger which charges the batteries at up to 30amps. All we do is put the generater in the dingy then plug the lead into the shis 240v shore connection and there you are plenty of power

[mikemacdonald]

thanks for your reply.
I think you have answered my question. We intend to liveaboard for extended periods, Rutland wind generator does well on moorings but your solution sounds perfect for us. Many thanks,
regards Mike

[theguerns]

Hi Mike
I have spent many years living on many types of boats and sal and I have been retired and living aboard for the past 8 years so if we can help you with any information please ask I was for many years a master boatbuilder and now run a marine consultancy Free to members of this site and Sal was the company sec for GM so plenty of experience. Just one other thi ng if you want to save on the petrol for the genny a D400 wind generater is the best for when you are sailing. Please have a look at our blog as we put some ideas there it is www.theguerns.blogspot.com

[Cliff]

Mike, Forget the over priced Hondas. Have a look at the Kipor range. they are ½ the price (or less) of the hondas and just as quiet (well to my ears at least) power for power.
I have run a honda along side a Kipor and could not honestly tell the difference in noise level. As for reliability I have around 1000+ hrs on my old Kipor 3000Ti and it's still running fine (treated it to a new sparkplug and changed the oil regular).

Kipor do a range of suitcase type gennies so you should find one to meet your needs without breaking the bank. If you get 5~6 seasons out of it what more are you looking for? by that time you wil probably be looking for a diesel genset for the bigger boat

[DaveS]

Following your previous posts on the subject I bought a Kipor 2600, not for the boat, but for playing with. (The ultimate idea is to run it on biogas - but that's another story.) I've been quite impressed by it. The waveform, particularly on light loads, is very good - quite a close approximation to a sine wave. It uses a small, fast revving (motorbike?) engine driving an alternator producing any old voltage and frequency which is then immediately fed into an invertor which generates a synthesised sine wave output.

I also bought an "El Cheapo" generator from Aldi. In terms of raw power it is incredible value: over 2.5kW for under £200, but the waveform is full of harmonics and the frequency is closer to 60Hz than 50Hz. Not an issue for most lighting, heating or power tools with universal motors, but some more sensitive loads might object. Interestingly, its engine drives a conventional alternator which I, naively, had expected should produce a decent waveform, but not so. I have, however, found similar levels of harmonics with "respectable" name bigger, industrial generators of about 10kVA which proved too much for some electronic loads.

[Cliff]

Dave,

Glad someone else agrees with me that they are pretty good little units. I metered mine - 49.95Hz irrespective of load, voltage 230~240v, load dependant and on overload she just shuts down. As for wave form - as damn near pure sine as one gets - difficult to see the difference between its output and mains supply. All in all I am pretty chuffed with the unit and not spending a lot of beer tokens adds to the "enjoyment"

[SeaCat]

All this sounds pretty good-oh, but what do these things weigh and how much fuel do they consume? The Honda would be a four stroke - is the Kipor also four stroke?

Regards

[Cliff]

4 stroke, 3~6/7 hours per gallon depending on load.
Do a google on Kipor and you will find several places selling them - most have full machine specs for each model or try "the greenreaper" website - seems to be pretty competitive on pricing.

[sahona]

DaveS, did you scope the field current waveform on the other beam, and could it be smoothed out a bit to give a better end result by any chance?
(by smooth, I mean a tank cap or something in the field current rectifier stack, to stop flutter in the regulator)

[mikemacdonald]

The Kippor 2600 looks very good. I want to use it as back-up charger when the wind don't blow, but also to run a tv and dvd in the evening, maybe charge the fridge and possibly a small fan heater occasionally, as well as standard power tools. Not all at once !!
Do you think that is reasonable, would I need to smooth out the supply for the telly and maybe a laptop
Mike

[DaveS]

DaveS, did you scope the field current waveform on the other beam, and could it be smoothed out a bit to give a better end result by any chance?
(by smooth, I mean a tank cap or something in the field current rectifier stack, to stop flutter in the regulator)

I take it you're referring to my remarks on the Aldi cheapy?

No, I've not got into the guts of the beast yet, so haven't had a look at the field current - if it's possible to get at it. The harmonic laden waveform looked surprisingly like what I've seen on a couple of 10 kW commercial generators I'm currently working on intermittantly, which have brushless ac excitation and rotating rectifiers (no slip rings). I would guess, however, that the Aldi cheapy is not so advanced and does use slip rings.

Your thoughts are most welcome. I hadn't considered AVR instability as a possible cause of harmonics. This has also triggered an idea for another line of investigation that I might try on my next Orkney visit.