ampair wind generator on yacht

[dlwilkes]

Just bought 27' yacht with ampair dolphin generator(1999) the previous owner has put a 3 amp fuse in the feed from generator then continued to a terminal block then run double set of wires from there direct to the two batteries. as this is my first excursion at boat electrics i could do with help with
1. does this need a fuse at all if so what rating?
2. Is trying to charge two batteries with this a waste of time
3. Is wiring direct from generator to batteries correct?
4. How can I test if generator still working
thanks a bunch (hopefully)

 

[sarabande]

Can you confirm its the vertical axis Dolphin - approx 4 watts IIRC

1. does this need a fuse at all if so what rating?

Assuming it's all 12v stuff. 3 amp fuse does sound enough as max output is < 0.5 amp.

2 Is trying to charge two batteries with this a waste of time
We need to know the capacity and type of the batteries. I'm guessing about 70 amphours each, so it's going to JUST keep them up to scratch if there's a lot of wind. Not really enough to properly charge them.

3. Is wiring direct from generator to batteries correct? With this small amount of charge you are unlikely to overcharge the batts, so you don't need a regulator between the generator and the batteries.

4. How can I test if generator still working
Stop the genny rotating. Disconnect the wires from the battery, and reconnect to a voltmeter set to up to 20v DC. Release the mill. Read output. Likely to be 14v-ish.


Even at 30knots/15metrespersec the output will be in the region of 350 to 400 mA, which is going to give you , err, 8AH per day. That's a tall order from a small piece of kit.

 

[dlwilkes]

Thanks a bunch for for very detailed reply to a novice boat electrician.You must have "scary powers" Even your assumptions re equipment and batteries are correct!!!!

 

[simonfraser]

check the output, put an ameter accross, you should have this option on your mulitmeter.
don't worry about over loading it LOL, the output is very low ? few 100 mA's.

 

[VicS]

[ QUOTE ]
check the output, put an ameter accross

[/ QUOTE ] Dont do this with the battery connected. If you put an ammeter across the battery youll blow the ammeter.

Fair enough to put it across just the output of a small wind genny though.

 

[simonfraser]

haha, yep forgot to state the 'obvious' /forums/images/graemlins/laugh.gif

 

[VicS]

There should be a fuse and it should be as close as possible to the battery. Its purpose will be to protect the wiring in the event of a short circuit from the very high current that the batteries can deliver. The fuse rating should be no greater than the rating of the wiring ... the thinnest bit if there is any difference. (3 amp will almost certainly be suitable)

I'd say the wiring between those batteries is not correct!
If the wiring effectively connects both batteries in parallel then it must be heavy wiring. If one of those is a starter battery then you have recipe for disaster if the wiring is not able to carry starter motor current.

I think it probably will be a waste of time with such a small genny but if you do want to charge both batteries then you should use a splitter (diode or other) so that the batteries are not simply connected in parallel. (You sure thats not what is fitted?)

As a novice you will find much useful info HERE

You may also find The 12 volt Doctor's Practical Handbook useful

 

[dlwilkes]

Many thanks folks for all info especially the "novice link" Great Help. I think you may be corrrrect VicS re parallel wiring though as on my initial attempt to start, the starter battery smoked on the connection until I took off the genny wires!!!

 

[VicS]

[ QUOTE ]
the starter battery smoked on the connection

[/ QUOTE ] Just as I feared. You starter would have been drawing part of its current from "the other" battery via the thin wires used to wire up the genny. Dangerous to the point that it could start a fire.