I am refitting a 17' Siren sailboat that has a 5 HP outboard motor. I
plan to put a 12V deep cycle battery aboard for VHF, sounder, lights,
etc. Can anyone point me to any do it yourself websites that discuss
this issue in particular?

I am interested in findiing out more about:
1. Battery size (~120 Ah should be more than enough).
2. Charging concepts (solar, outboard). Willl probably be leaving the
boat in the marina, and might not have shore power.
3. Battery monitoring. Since power requirements are low, I do not
want to spend a lot on expensive monitoring devices.

Jim

Jim Thompson wrote:
I am refitting a 17' Siren sailboat that has a 5 HP outboard motor. I
plan to put a 12V deep cycle battery aboard for VHF, sounder, lights,
etc. Can anyone point me to any do it yourself websites that discuss
this issue in particular?

I am interested in findiing out more about:
1. Battery size (~120 Ah should be more than enough).
2. Charging concepts (solar, outboard). Willl probably be leaving the
boat in the marina, and might not have shore power.
3. Battery monitoring. Since power requirements are low, I do not
want to spend a lot on expensive monitoring devices.



Google for "The 12 Volt Handbook", it will tell you all you need to know
about boat electrics.

Jim

--
Remove "nospam" from return address.

Did you try what you suggested?
First check before you send this kind of info.
Any question here could be answer with Google for "..........."

Jim
I have copy of "The 12 Volt Handbook" - but it is 12Mb in total
Let me know here (rbe) if you need it and you can accept this size of
attachment
Adam

"Dennis Pogson" wrote in message
...
Jim Thompson wrote:
I am refitting a 17' Siren sailboat that has a 5 HP outboard motor. I
plan to put a 12V deep cycle battery aboard for VHF, sounder, lights,
etc. Can anyone point me to any do it yourself websites that discuss
this issue in particular?

I am interested in findiing out more about:
1. Battery size (~120 Ah should be more than enough).
2. Charging concepts (solar, outboard). Willl probably be leaving the
boat in the marina, and might not have shore power.
3. Battery monitoring. Since power requirements are low, I do not
want to spend a lot on expensive monitoring devices.



Google for "The 12 Volt Handbook", it will tell you all you need to know
about boat electrics.

Jim

--
Remove "nospam" from return address.

I have lurked on this website for 5 years. I have been googling
extensively without finding any comprehensive discussion forums or
websites on this particular subject (small sailboat with or without an
outboard motor, but owner wants electronics on board), and I own The
12 Volt Handbook, Nigel Calder's book and several other marine
electronic references. I have extensively rewired our 30' powerboat
over the years. That's why I am looking for a comprehensive source of
information for this particular problem, ideally someone who has
already done such project recently. Technology has evolved very
rapidly in this specific area in the past couple of years. Hence my
question.

The specific case example that I am looking for is this:

17' sailboat.
Weekend/weekday sal****er sailing. maybe 1-2 nights overnight, some
nights camping out in the slip.
In-water at the marina slip between trips, with or without shore
power.
12 V DC power for:
VHF radio.
Sounder.
Nav lights.
Cabin lights.
DC socket for recharging cellphone, camera.

My thoughts so far a

1. Small 75 -120 Ah (?) pure deep cycle battery.
2. Charging system:
2a. Solar panel if not on shore power? Practical? Size?
2b. Shore power charger. Stray current not an issue if no metal from
the boat is in the water. Does not need to be heavy-duty, but needs
to be "deep cycle" aware.
3. Battery monitor: voltage, amperage draw, and maybe even one of the
Link type battery monitors that can estimate remain Ah, but cost
containment is and issue, and overkill is not in the specs.
4. Wiring: that's the easy part (AYBC specs, etc). The standard books
are fine for this, and the local boating stores sell all the products
I need.
5. I have no experience with LED nav lights, but there seems to be
plenty of info on google for that subtopic, and there was a good
thread on this newsgroup recently.

I am building my own case study for this application he
http://jimthompson.net/boating/Siren/Electrics.htm

Jim

The book is a good suggestion, but I'm curious, how much output do you get from
the alternator of a 5 hp engine? I know that some 9.9 engines have a 12 Amp
alternator, but you don't get that unless you're running hard. Also, you have
to consider how often you'll run the engine, and for how long, etc. For
instance, if you have to power for a while to get out of a river, you may
generate enough to provide for a day's usage. And if you use it every week, not
much will lost to self discharge.

On the other hand, if you don't use it often, a small solar panel might be
better.

Also, an AGM battery will have a lot less "self-discharge" and is easier to deal
with on a small boat.



"Jim Thompson" wrote in message
...
I am refitting a 17' Siren sailboat that has a 5 HP outboard motor. I
plan to put a 12V deep cycle battery aboard for VHF, sounder, lights,
etc. Can anyone point me to any do it yourself websites that discuss
this issue in particular?

I am interested in findiing out more about:
1. Battery size (~120 Ah should be more than enough).
2. Charging concepts (solar, outboard). Willl probably be leaving the
boat in the marina, and might not have shore power.
3. Battery monitoring. Since power requirements are low, I do not
want to spend a lot on expensive monitoring devices.

Jim