Hi all, I'll find out this week if I'm a new owner. God help us all.

The boat is a 30' Wellcraft.

We're going to use the boat almost exclusively on weekends with probably 1
or 2 times in the summer where we'll be able to spend a week on it. It will
basically be our cottage. We're not new to cruising, just new to having our
own boat for cruising.

The boat doesn't have a generator and I'm not sure if I need one. Here is
what I'm thinking, hopefully you guys can give me some advice.

What if I set it up with 2 deep cycle batteries, a high output alternator on
one engine and an inverter.

We're not looking to run a small city, just make some coffee and toast in
the morning, possibly run a bit of stove or microwave at lunch or dinner and
maybe watch a movie in the evening. If I'm working then I'll probably want
to either charge my laptop or run it on ships power for a while.

This of course on top of regular DC usage for water, fridge, lights, etc.

It doesn't have air although if we go hardcore into the later fall season
and early spring we'll want to bring a little heater with us.

My thinking is this. It will be hooked up to shore power all week with the 3
stage charger making sure my house bank is topped up. If we run down below
the threshold while were at anchor I can run the engine (I know, it's a very
expensive generator) to get us back up to about 80% charge.

That's assuming we anchor the entire time and not go for a mid-day cruise
which will have the benefit of charging us back up. And also assuming that
we don't go for a visit to somewhere with dockage and shorepower -- which we
would most definitely do for a day or so during the weeklongs, and probably
do during some of the weekends.

It also seems to me like I could configure for this and try it out to see
how it works. If I find I'm running the engine too much I could then buy a
little generator since the rest of the setup as described above would be
required anyway.

Do this sound like a reasonable approach?

"Paul" wrote in message
le.rogers.com...

~~ snippage ~~

Do this sound like a reasonable approach?

Doable? Yes.

Should you do it this way?

No.

Guaranteed that you will find a way to drain the batteries more
than once.

Spend the money now and get a little 1500 watt Honda generator
or equivalent - I carry one on my offshore center console just to
run the radios and electronics while drifting.

Makes more sense than constantly charging and discharging the
batteries.

Just my opinion.

Later,

Tom

Power from a battery bank is real easy to get these days. Of course,
boat power from a boat parts place costs three times as much for the
same technology.

The problem with DC power is the very limited SOURCE, the storage of
power in batteries. Deep cycle batteries, the kind you can discharge
down without eating holes in the plates like starting batteries will,
are rated in ampere-hours (AH) at some rate that makes the
manufacturer look good, like 10A or 20A...it's on the label, or is
supposed to be. 20A at 13V = 260 watts out power output. The
inverter is going to eat up about 5-10% of that, say 20 watts for fun,
because no inverter is 100% efficient, so you're left at that level
with 240 watts of AC power, a thousand watts short of the coffee maker
which draws 1200 watts for 10 minutes, then, if it's got a pot heater,
50w continuously.

The AH rating on the house batteries DROPS significantly as load
increases on them. The chemistry freeing up electrons and moving the
dissolved salt created when you discharge becomes much less efficient
the more electrons you use.

Let's look at the coffee pot load for a minute. If the coffee pot
uses 1200 watts and the inverter at this load level puts out 90% of
what it gets from the battery to the pot, 1200/.9=1333W from the
battery. Let's pretend the heavily loaded battery and the corroded
cables to the inverter put 12V on the inverter under load (it's
probably LESS at this current level). 1333W/12V= 111 amps of load at
12V. Make SURE the wiring from the inverter to the battery is LARGER
than the wires to the starter! Starters on gas engines draw about 80A
starting the beast. We're over that, just making coffee!

Question - How long can you run the starter before the battery is
dead? 3 minutes of CONTINUOUS cranking? 4? 5? It ain't gonna make
10, is it? At 111 amps, we're gonna need a powerful battery to make
that coffee, aren't we?! See the math working, here? Think the 12V
wires will get warm?..(c; They will. Small ones will melt....

Question - Armed with this information, how much current will a Heart
4000 watt inverter draw that's, say, 95% efficient?

4000W/.95=4210W/12V=THREE HUNDRED FIFTY AMPS! Wow! We're gonna need
some POWERFUL HEAVY WIRES to hook that baby up! #000 is 200A
service!

Now, let's be honest. Most boaters, even the rich ones, are
cheapskates. They're using the golf cart batteries from some discount
house rated at 225AH, 6V with two in series to get 12V. These
batteries are the most bang for the buck. My stepvan has 4 of them
for house batteries on a 500W inverter and they work just fine at an
80A load. They're probably only 160AH at 80A, but that's still 2
hours at FULL LOAD of all my DC and inverter loads...not bad. But,
350A is just gonna make them EXPLODE from internal heat generated way
beyond their capacity. You CAN add more banks, if you got the room,
in parallel. Four banks in parallel would reduce the load on each
battery to under 100A on that beast. See the problem?

1333W for 10 minutes on a carafe coffee maker that doesn't have a
heater IS doable. 111A for 10 minutes = 111x.16667hrs = 18AH.
That'll work on the golf cart batteries derated to 150AH at 111A.
It'll make about 9 pots of coffee, won't it? That works.

You can do the math approximations for your other loads. As you can
see, there really isn't many Watthours of electricity available from
225AH batteries.

I have a saying....."Nothing is funnier than watching a yachtsman with
a new 4KW Heart inverter carrying his electric heater down the dock
with a big smile on his face."......(c; Think about it....

He's gonna need those old WW2 diesel-electric submarine batteries we
used to service at Charleston Naval Shipyard's battery shop. EACH 2V
cell was about 7 ft tall, 4' x 3', weighed about half a ton and had
6,250AH rating at, I think I remember, 400A load. 6 of them will heat
the boat.....er, ah.....if it'll float.

Now, if you want some NEAT power, serious power, go to a Honda dealer
and look at the EU2000i tiny portable gas generator. It weighs about
35 pounds, makes very little noise, is amazingly easy on gas with its
OHV 4-stroke engine and the computer in it varies the engine speed
depending on your load, dropping it down really low at low loads under
800W because you always get 60 Hz filtered good enough for computers
out of it 2KW inverter! I use the EU1000i 1KW model in my service
truck. It'll pull my little 5000 Btu AC! MUCH more efficient, MUCH
less weight and you can load it to 1500 watts 24/7 for about 6 gallons
of gas! Before buying it locally, though, put EU2000i into google.com
and find the best price. Mine came from a sawmill supply company in
Oregon, on the other side of the country from Charleston. I can buy a
LOT of "service" for the $380 I saved....



Larry W4CSC

"No, NO, Mr Spock! I said beam me down a WRENCH,
not a WENCH! KIRK OUT!"

Small, gasoline powered generators aren't necessarily noisy or dangerous.
And, you don't have to refill them when hot - especially with the limited
use this boater intends. Refill it when it's not hot, before or after each
use; they run for a long time on a tank of gas.

"Paul" wrote in message
le.rogers.com...
Remember that you can't put an
inverter in the engine room of a gasoline powered boat, so make sure you
have a good place for it.

Didn't know that, thanks. (I wonder how much I don't know, I bet it's a
big
list).

As for the suggestion of a small, gasoline powered generator. My
feelings
are that those are noisy and dangerous, both from fire/explosion hazard
if
you have to refill it while it's hot, and the CO hazard if you run it
anywhere inside the cockpit. The only place I'd feel safe running one
would
be out on the swim deck, but they I'd be worried about salt water
splashing
and corrosion. I'd stick with the inverter solution.

We'll be in fresh water lakes only but your point is well taken. I can't
see
myself wanting to carry spare fuel on board anyway so refuelling hot
wouldn't be an issue.

Aside from the inconvenience of locating it somewhere and starting it up
each time I want to make a bit of coffee, the noise is the biggy. To have
a
nice quiet anchorage and watch the sun rise while listening to that thing
pounding away ... well, you can see my point.

If the setup isn't unreasonable I guess I have to start doing some math. I
would really feel better though if anyone else is set up this way, or
tried
it and found out that it's non-workable.

You may not need as much ac power as you think...although my boats were
"all electric" and had 6.5 kw gensets, there were times when I didn't
want to listen to the damn thing.

We're not looking to run a small city, just make some coffee and toast in
the morning,

Easily done without power. The toast--and even eggs and bacon--can be
cooked on a marine propane grill--which you'll want anyway. Coffee can
be made over a propane camp stove--either in a percolator, or by
boiling water and using a Melita or a fresh press. Grill and stove
properly mounted to meet safety standards in the cockpit, of course.

possibly run a bit of stove or microwave at lunch or dinner...

Again, use the grill for your meat, corn on the cob, baked potatoes
etc...you can even steam veggies in foil packets on the grill. Salads
and sandwiches for lunch if you don't want to grill burgers and dogs.

A little advance prep at home, and you can eat like kings aboard with
almost no effort and very little cleanup, without electricity.

maybe watch a movie in the evening.

Buy a DC powered TV. Or read a good book instead.

If I'm working then I'll probably want
to either charge my laptop or run it on ships power for a while.

I ran mine off a small inverter for use in cars--about $50 at any
computer retailor or Radio Shack...installed a "cigarette lighter"
receptacle in my dinette for it.

This of course on top of regular DC usage for water, fridge, lights, etc.

The fridge is the biggest battery drain on most boats. The more often
the door is opened, the more the compressor has to run....conversely,
the less often it's opened, the less it runs and the less power it
needs. Conserve battery power by keeping your drinks in a cooler and
reserving the fridge for food (may not be necessary when only the two of
you are aboard, but almost essential if you have kids and/or when you
have guests aboard). Last thing before you turn in for the night--after
you're sure the door won't be opened again, turn it off at the
breaker...it'll stay cold enough even to keep ice cream till morning.
Just don't forget to turn it back on again when you get up!

Just some suggestions that worked for me for nearly 20 years.

Peggie
----------
Peggie Hall
Specializing in marine sanitation since 1987
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and
Other Sources of Aggravation and Odor"
http://www.seaworthy.com/html/get_ri...oat_odors.html


It doesn't have air although if we go hardcore into the later fall season
and early spring we'll want to bring a little heater with us.

My thinking is this. It will be hooked up to shore power all week with the 3
stage charger making sure my house bank is topped up. If we run down below
the threshold while were at anchor I can run the engine (I know, it's a very
expensive generator) to get us back up to about 80% charge.

That's assuming we anchor the entire time and not go for a mid-day cruise
which will have the benefit of charging us back up. And also assuming that
we don't go for a visit to somewhere with dockage and shorepower -- which we
would most definitely do for a day or so during the weeklongs, and probably
do during some of the weekends.

It also seems to me like I could configure for this and try it out to see
how it works. If I find I'm running the engine too much I could then buy a
little generator since the rest of the setup as described above would be
required anyway.

Do this sound like a reasonable approach?

Thank you all for your advice and for the time you spent replying, it's much
appreciated.

I laughed when I realized that it never occurred to me to use a small
invertor for the laptop ... when Peggie said it I realized it was the most
obvious thing in the world but it had never occurred to me and probably
wouldn't have for a while. Geez ... I can be thick headed.

Laptop also solves the problem of watching a movie in the evening ... built
in dvd player.

My friend has a 1kw Honda generator that he offered to me and now I'll give
it another think. I also wouldn't mind having it here at home in the winter
in case we lose power (I'm in Ottawa, everyone here remembers the ice
storm).

I've been worried about propane on a boat because of its tendency to settle
low but I'll see how everyone else is rigged and check out the rules on
that, perhaps that deserves a rethink too.

I appreciated the math on the coffee maker but I'm going to run those
numbers myself. It seems to get pretty complex.

I have about a million more questions ... thanks again for your help on this
one.


"Paul" wrote in message
le.rogers.com...
Hi all, I'll find out this week if I'm a new owner. God help us all.

The boat is a 30' Wellcraft.

We're going to use the boat almost exclusively on weekends with probably 1
or 2 times in the summer where we'll be able to spend a week on it. It
will
basically be our cottage. We're not new to cruising, just new to having
our
own boat for cruising.

The boat doesn't have a generator and I'm not sure if I need one. Here is
what I'm thinking, hopefully you guys can give me some advice.

What if I set it up with 2 deep cycle batteries, a high output alternator
on
one engine and an inverter.

We're not looking to run a small city, just make some coffee and toast in
the morning, possibly run a bit of stove or microwave at lunch or dinner
and
maybe watch a movie in the evening. If I'm working then I'll probably want
to either charge my laptop or run it on ships power for a while.

This of course on top of regular DC usage for water, fridge, lights, etc.

It doesn't have air although if we go hardcore into the later fall season
and early spring we'll want to bring a little heater with us.

My thinking is this. It will be hooked up to shore power all week with the
3
stage charger making sure my house bank is topped up. If we run down below
the threshold while were at anchor I can run the engine (I know, it's a
very
expensive generator) to get us back up to about 80% charge.

That's assuming we anchor the entire time and not go for a mid-day cruise
which will have the benefit of charging us back up. And also assuming that
we don't go for a visit to somewhere with dockage and shorepower -- which
we
would most definitely do for a day or so during the weeklongs, and
probably
do during some of the weekends.

It also seems to me like I could configure for this and try it out to see
how it works. If I find I'm running the engine too much I could then buy a
little generator since the rest of the setup as described above would be
required anyway.

Do this sound like a reasonable approach?

"Paul" wrote in message
le.rogers.com...
Guaranteed that you will find a way to drain the batteries more
than once.

I was under the impression that the inverter could be set to shut off at a
pre-set level of discharge, say 60%. The house bank would also be separate
from the starting batteries so were they to go flat it would mean
decreased
service life and no toast that morning but I wouldn't be in a pickle as
far
as engine starting goes.

My fault - I misunderstood you - I thought you were going
to run off of the engine battery bank.

Spend the money now and get a little 1500 watt Honda generator
or equivalent - I carry one on my offshore center console just to
run the radios and electronics while drifting.

Hmm, I may know less than I thought. I thought running those smaller DC
units would be fine off the house bank.

I'm not a big fan of inverters for anything. It just seems a
little silly to convert AC (overnight charging) for storage in
DC {batteries) for reconversion to AC (inverter) again when
for a small additional amount, you have a nice quiet little
generator that will do all you want and a tad more.

I will admit that I have a12 v DC power supply that the Honda
is connected to, but it's very efficient, I don't use my batteries
except when the engines are running and it's quiet which is
great. I have a small refrig in the console that it runs to keep
water/soda and sammiches cool. I've been trying to figure out
a way to refrigerate my live wells too. ;)

Also, I have a lot of electronics that I run all the time - two
radios, radar, sonar, GPS/plotter, live well pumps (and most
importantly, the refrigerator with the sammiches). The way I
figure it, the less constant duty load I place on the boat batteries,
the better off I am.

Anyway, it's just my opinion. And I will readily admit that
sometimes my way isn't anywhere near the way others will
do it and I make no claims to have the inside track on what
is or isn't "correct" - it's just the way I do things.

Good luck and have fun.

Later,

Tom

On Thu, 31 Jul 2003 11:49:45 GMT, "Rural Knight"
wrote:


"Paul" wrote in message
ble.rogers.com...

~~ snippage ~~

Do this sound like a reasonable approach?

Doable? Yes.

Should you do it this way?

No.

Guaranteed that you will find a way to drain the batteries more
than once.

Spend the money now and get a little 1500 watt Honda generator
or equivalent - I carry one on my offshore center console just to
run the radios and electronics while drifting.

Makes more sense than constantly charging and discharging the
batteries.

Just my opinion.

Later,

Tom


"...offshore center console.." ???
....crap...I was just starting to like you. )
noah

....saw an awesome CC today on the highway, headed South on I-87 about
at Saratoga in a nasty rain. A "Fountain", maybe 28', with twin
225's. I fell in love, but I had to leave her. (
noah ---- smelled fish all the way to Albany

Courtesy of Lee Yeaton,
See the boats of rec.boats
www.TheBayGuide.com/rec.boats

Anyway, it's just my opinion. And I will readily admit that
sometimes my way isn't anywhere near the way others will
do it and I make no claims to have the inside track on what
is or isn't "correct" - it's just the way I do things.

Your opinion is much appreciated, everyone's has been. I figured everyone's
answer would be different but that's because we all have different setups
and priorties, but it really helps to hear it all.

I'm going to leave the boat rigged the way it is for now and just get used
to how everything works. Once I get used to it and understand it all a bit
more I'll plan out a solution but I'll be thinking over all the options you
all have mentioned.

I have no doubt I'll figure out a good way to have my coffee and toast while
at anchor (eventually).

"noah" wrote in message
...
On Thu, 31 Jul 2003 11:49:45 GMT, "Rural Knight"
wrote:


"Paul" wrote in message
ble.rogers.com...

~~ snippage ~~

Do this sound like a reasonable approach?

Doable? Yes.

Should you do it this way?

No.

Guaranteed that you will find a way to drain the batteries more
than once.

Spend the money now and get a little 1500 watt Honda generator
or equivalent - I carry one on my offshore center console just to
run the radios and electronics while drifting.

Makes more sense than constantly charging and discharging the
batteries.

Just my opinion.

Later,

Tom


"...offshore center console.." ???
...crap...I was just starting to like you. )
noah

...saw an awesome CC today on the highway, headed South on I-87 about
at Saratoga in a nasty rain. A "Fountain", maybe 28', with twin
225's. I fell in love, but I had to leave her. (
noah ---- smelled fish all the way to Albany

I almost bought a Fountain - came really close. It was
located in Florida though and I didn't feel like running it
up the coast this spring. I would have had to wait to
trailer it, so I scratched that one off the list.

I have a Contender 31 although why they say it's a 31 I don't
know because it's 32 1/2 feet long - I call it a 32. I just
bought it this year in fact. Spring and Fall are my prime time
fishing periods and this boat gets me to where I want to go
in the shortest time possible.

I have twin 225 Merc Optimax - awesome engines and if you don't
push the revs, they are fairly efficient.

For inshore, I have a 200C Ranger center console with a 200
Evinrude FICHT which I also like a lot. That boat is used
primarily inshore and for the larger sweet water lakes around here.

I also have a small aluminum rowboat for smaller ponds for summer
flyfishing with a brandy new Briggs & Stratton 5 hp outboard. Cute
little engine.

And then there is my '74 Christ Craft/Thompson Corsair project
boat. And a Glastron 20 foot project boat which I'm not really
sure what I'm going to do with other than maybe strip the engine
out of it, sell the trailer and junk the hull.

Later,

Tom