"Skip Gundlach" skipgundlach sez use my name at earthlink dot
fishcatcher (net) - with apologies for the spamtrap wrote in
:

Hi, Larry, and thanks for the thought provoking, left below for
reference.

However, one snippet which I don't understand - can you elaborate?

I doubt many here will be powering the shore power throughout the
boat
with
the battery killing inverter, don't you?.....

Battery killing inverter? Most of what I read these days suggests a
static load of well under an amp, some are milliamps. Running any
electrical device will kill a battery eventually if it's not got the
power replaced (which we expect to do in spades, or, as you've noted,
our own power company should be able to cope with extended periods of
no-replacement) - how's this different?

Do the math. Let's say we have a BIG inverter, 4KW continuous. This is
great for TEMPORARY loads that need 4KW for a few minutes, like your coffee
maker. But, as I jokingly put it, may boaters think they have their own
"power station" when they buy one of these beasts. Case in point:

1500W heater - 12.5A@120VAC - about 120A at 13V.....x 24 hrs = 2880AH

To provide for a simple electric heater and only drawing the battery banks
down to 70%, not zero which destroys them....2880/.30 (30% of battery
capacity) = 9,600AH battery bank. How big did you say those cells
were?...(c; Hence my comment, "The funniest thing is to see a boater with
a new 4KW inverter carrying his electric heater down the dock with that
smug grin on his face."

I've seen them incredulous that their 5KW inverter can't run the boat's air
conditioner for the weekend anchored out. Math is not one of their
majors...(c;


We have yet to decide about the capacity of the inverter we'll use.
Likely the mikey or coffeemaker will be the biggest draw; I assume
that will want something on the order of 1500w. I have a 1/3hp
grinder/polisher and a skilsaw which might also have a pretty good
startup load, so I'm thinking of 2kw as my "solution" to house power.

2KW is fine.....for INTERMITTENT loads.


As we next to never expect to be at shorepower except during haulouts
(and even then, should have no particular need, with our solar and
wind), we'll want to make our various outlets be both - inverter and
shorepower.

Hmm...5A from a big solar panel or 15A from a wind generator = 5X12hrs=60AH
per day if the sun shines or 360AH wind power in a full gale 24/7.

Not much of a real powerhouse, is it, huge batteries or small batteries...

Plan on using the big alternator on the engine every day in this
configuration.


As we don't yet know how we'll use the computer and entertainment
stuff, we assume we'll want to have our outlets available everywhere
they are now, as well as some other places I'll install in the next
few weeks. None of those loads are very big, of course, but running
drop cords isn't my ideal power solution, even if they are in
raceways. So, back to the question of central power (and
switchability for shore power/house power) and what to do...

The "drop cords" aren't laying around. You can use electrical cable if you
like, wired into the boat. The inverter electrical system on Lionheart is
wired into the boat and plugged into the inverter.

As to powering the boat from shore and inverter, you install a transfer
switch between the sources, ensuring the inverter is never connected in
parallel with the power company from the dock. It's, essentially, a double
pole switch, mounted in a box with a lockout so you can't run both,
simultaneously. Any home generator transfer switch will work on your
inverter system.