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Oscarpop
12-10-12, 21:05
So I have installed my air breeze wind gen on the boat and have a good battery monitor to watch both charge in and out.

I have used the minimum diameter cables recommended for a 10 m run and everything is set and working well.


My question is, the ybw test shows that this unit should produce 14a at 25 kts.

I have sat today in 25 kts of wind and only managed to get 7a

Have I missed something? Or would increasing the wires diameter help? The manual says that using the wires I have should only create 5% loss due to resistance.

Many thanks

noelex
12-10-12, 21:14
We're you measuring the windspeed at the masthead?
It's easy to calculate the power loss in the wires. Just post the wire size, length of run and current and someone will calculate it for you, but It wires losses won't account for the difference between 7 and 14A.

clyst
12-10-12, 21:16
Welcome to the Air Breeze disappointment club .I have an air breeze set up as per instructions for the last 4 years and yet to experience the claimed output . I am truly disappointed with the unit . When away from shore supply we normally have to run the engine to maintain a reasonable battery level. Dont get me started on the noise ---- even using the air breeze mounting kit . Sorry for the negativity but utter rubbish in my experience

Oscarpop
12-10-12, 21:45
This was the ybw test

http://www.windenergy.com/sites/www.windenergy.com/files/Yachting-Monthly.pdf

Unless I have got it wrong, the unit should be producing 12 amps at 25 kts.

I am not sure if ybw simply took air breezes data and pasted it in.

robertj
12-10-12, 21:52
i have a rutland 513 and its hopeless. the wind speed amps they quote are miles out, so i think its the same with these.

Seajet
12-10-12, 22:26
Various chums have had various wind generators and all have been disappointed; this was for coastal weekend and occasional holiday use, but the sets were left going 24/7 in summer, in one case winter as well.

Coupled with noise, windage, risk of scalping and bearings running out - with even more noise -, I'm surprised anyone bothers with wind generators apart from liveaboards desperate for any amp going !

nigelmercier
12-10-12, 22:37
How full were your batteries when you did the test?

Seajet
12-10-12, 22:38
Maybe I should add that I know of the Test Pilot who designed the original Ampair and I do know personally the Test Pilot who handled dealings for him while he - the designer - was abroad in his boat; that was a very long time ago !

The original designer, sadly no longer with us, was a blue water sailor himself in a Nic 38 when he retired from test flying; the object was most certainly not money-making, but to give fellow long distance sailors - who were sparse in those days - a chance of charging their batteries.

The business was taken over quite a while ago and I have no experience of their systems, but I can assure everyone the system began with the best intentions !

Mistroma
12-10-12, 22:43
i have a rutland 513 and its hopeless. the wind speed amps they quote are miles out, so i think its the same with these.

+1 on that. I suspect it is a combination of diff. between wind at masthead and sea-level plus shadow/eddies caused by mast, sprayhood etc. Manufacturers probably quote "wind-tunnel" type figures i.e. What you'd get if you mounted the gen. on a 10m mast sticking out of the sea (without a boat in sight to support it or interfere with airflow.

Solar is much more cost effective (though wind-gen does have a place once you've got all the solar you can fit).

William_H
12-10-12, 23:46
The current measured going into your battery can be a lot different to the max capability of the gen.
So you may have a regulator which is reducing charge current because it senses the battery is well charged.
If there is no regulator then current may be simply reducing because the battery is well charged.
You may need to feed the gen into a resistor to get the max current at probably 12v. Perhaps a MPPT type regulator as used for solar would boost the charge current.
None of this diminishes your disappointment at actual current into battery of course. good luck olewill

macd
13-10-12, 05:08
I'd guess, like others above, that the batteries are fairly well charged and not accepting the potential full output.

Despite the negativity, wind gens can definitely be useful source of power, but used alongside solar panels, rarely as stand-alones. In the trade winds even relatively small ones such as the Aero4gen produce useful power. In most of the Med, on the other hand, their main contribution to power output is to cast a debilitating shadow over the panels (one reason I've just taken one off my new boat).

Then there's the noise, (although some are quiet)...

Oscarpop
13-10-12, 06:25
We had just returned from a week up the coast with no electricity for 2 days and only a couple of hours motoring.

My 300ah domestic bank was 70% full, so I'm guessing that the regulator would be applying full charge

( on a separate note, I have the mounting kit and poles supplied by the air breeze people, and I think that the noise levels are acceptable. It is far quieter than my friends installation which was done using ss poles)

BarryH
13-10-12, 07:42
I had a wind generator on the boat when I purchased it. In short it was ****. I would have been better off using a bicycle dynamo.

I went out and bought a 15 watt Maplin solar panel for 60 quid and a 10 quid regulator. I leave it connected all the time and always come back to fully charged battery. 70 quid verses 300 odd quid. Its a no brainer really.

Marsupial
13-10-12, 08:16
you really need to know the wind speed at the wind gen before you can reach any conclusions. This story illustrates the point; a friend of mine was sailing in the ionian last summer and noticed his wind speed instrument was reading 55kts, which was strange because as far he was concerned the boat was becalmed, he discussed the apparently abnormal reading with his crew for some time then boat was blown flat and all hell let loose. They did survive but a lot of deck kit didn't.

wotayottie
13-10-12, 08:27
We had just returned from a week up the coast with no electricity for 2 days and only a couple of hours motoring.

My 300ah domestic bank was 70% full, so I'm guessing that the regulator would be applying full charge


Thats to misunderstand the way the system works. The airbreeze itself will limit the charging voltage to 14.1 as it is set from the factory. But the current flow depends on the difference between that voltage and the back voltage of the batteries. At 70% charged the battery back voltage might be around 12.5 volts so the current flow would depend on the 1.6 volt difference between the two. It would be limited by the combined resistance of the feed wires and the internal resistance of the battery itself. Your figures suggest this totals 0.22 ohms.

OK that explanation is over simplified but it gives the basic principles as I remember them. As for the discrepancy against test figures, the ybw test records 12 amps at 23kn into a half charged battery which would mean a lower back voltage than yours at 70% charge and therefore a higher current flow. Not sufficient to account for the 40% shortfall but certainly for part of it.

You see exactly the same effect with solar panels and with alternators. My boat has a 60 amp alternator using a Sterling regulator and into 200 aH of service batteries. By the time the batteries are 70% charged the charging current has dropped to below 20 amps despite the charging voltage being 14.8. There simply is a limit to the speed at which you can force feed amps into lead acid batteries.

NornaBiron
13-10-12, 10:19
Welcome to the Air Breeze disappointment club .I have an air breeze set up as per instructions for the last 4 years and yet to experience the claimed output . I am truly disappointed with the unit . When away from shore supply we normally have to run the engine to maintain a reasonable battery level. Dont get me started on the noise ---- even using the air breeze mounting kit . Sorry for the negativity but utter rubbish in my experience

+ 1

Ours has been back to the manufacturers three times in less than two years with various faults, they know that we will never say a good word about it and yet they still won't give us our money back. Carriage back and forth has now reached the level of purchasing a new wind gen (most of it out of their pockets, we refuse to pay any more carriage).

john_morris_uk
13-10-12, 10:36
There simply is a limit to the speed at which you can force feed amps into lead acid batteries.I suspect that's the bit that most people don't get. The physics is that you just can't force charge into the plates at some 'high rate' as the batteries get nearer to being fully charged. We have similar issues with out wind generator but I am fairly confident its working to spec.

PS We have a Superwind and its very very quiet.

http://www.superwind.com/swe/index.htm

I have experienced some other makes and they are annoyingly noisy. They always make me feel I am sailing in a F5 when its a F3.