Database for Questions &
Answers: Power on Board.
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1.
I have
priced a 90 watt wind generator (10 m/s), this is little compared to youers,
what do you think?
2. I dont
have much on the boat that draws power, maybe 25 Amps. I have a 56
watt solar panel. Is this good?
1. Wind generator. i have a wind genny that i try not to
use. The day i have enough (i my dreams) power i will try to sell it. The
most important thing for me with the genny is that it is quiet. Many of them
make a lot of noise and it is not fun for you or the other people on the
anchorage. Personally i would like to have a Rutland. They are quiet and give
some power. It is also important that it can give power with little wind and the
Rutland do. The one i have is giving a lot of amps but it requires a lot of wind.
If i am sailing with the wind (we all try to do this as often as we can) it
almost never spins. Regardless of what people think of wind generator, they are
very efficient, work 24 hours in rain and in cloudy conditions. Whenever there
is overcast and youer solar panels don't give much the wind generator will keep
working. If i were to buy a new one i would get one that gives about 2 amps in
low wind and don't make a lot if noise.
Battery:
-
Ordinary led batteries (with water) should not be used
more than 50% of the rated power. By this i mean that if youer battery is rated
at 100 amp. hours you can only use 50 amps before you have to recharge.
- To find
the status of youer battery you use a volt meter. A fully charged battery (that
has been left with no charge or load for one hour) can have a charge of up to
12,7 volts. If it has 11,7 volts it is broken. If you measure while under way and
you have 12,2 volts you have used half the power. You
HAVE to recharge at this point. Below 12,2 volts the battery starts a sulfating
process and the plates inside will destroy itself. (This is not something you can
recharge). However you have to try and fail a bit because you seldom have the
opportunity to do a good measurement while under way, something is always charging
or drawing so it is hard. teks. if you just used 5 amps for something the battery
might show 12,2 volts but be on its way back up again and ten minutes later it
can show 12,5.
-
If you buy New batteries buy the same brand, never, never hook a new
battery up together with an old one, the old one will kill and bring the new
one down to its 'old' level very fast.
- Gel batteries are of course the best,
they can take more charge and more discharge but are expensive. Deep cycle
batteryes are almost the same but a little bit cheaper. As i said this is the
best but they cost the doble of led batteries.
Power accounting:
To know what kind of charging
devices you need first you need to know how much power you use.
S/Y Spetakkels power
accounting (24 Houers).
|
Load source |
Power / Ampere
(A) |
Time used
(B) |
Amps You need.
(A x B) |
Lights inside |
2 |
3 |
6 |
Lights outside |
0,5 |
3 |
1,5 |
Anker light |
0,2 |
12 |
2,4 |
Fan at night |
0,35 |
10 |
3,5 |
Computer, movies |
5 |
3 |
15 |
As you can see my usage is mostly for the
computer since it takes more than 50% . I should have
purchased a more power friendly computer. This 'budget' is at anchor and
only an exampel. Include everything when you make youer own and make one
for anchor and one for sailing. |
28,4 Ampere |
|
As mentioned this is only for example. Remember that you have to have twice as
much power as the result in battery capacity since you can only use half the rated power.
The truth is that most boats are
struggelign to get enough power. Roughly one can devide the sailors in two
seperate groups. Those who have a fridge and need to run the engine or generator
for two houers a day and those who dont have a fridge and still are struggeling
to avoid engine usa.
If you have a 25 amp a day use you can make it with one
battery but i still recommend two (pluss on for the engine)
Youer solar panel of 56
watt is good. Nothing is better than solar power. Remember to keep the regulator
on the inside and use big cables between the panel and the batteryes. It is
foolish to loose power in transport.
|
Two of my solar panels. This would work significantly
better if i had them on a place with no shadow but until i get a new
bimini roof this is where they will have to stay. .
|
|
My wind genny, Airmarine. This is the most powerfull one on the
market and the one that makes the most noise. Hated by most cruisers.
TIPS: If you have the space you can significantly reduce the noise by
mounting it on the mast high up. (easy on ketch)
|
Kjell O.
Stave |