Stephen Trapani wrote:
Peter Bennett wrote:

The microwave, power tools (and possibly an electric
kettle) are OK, as they are short-term loads, and the total
ampere-hours used by them should be fairly low. The TV and boom box
would be on for longer periods, but are fairly low draw, so may also
be OK - but I would definitely want a separate starting battery!


So in order to do without the seperate starting battery I can manage
with careful planning, etc?

Only if you never go outside the range of SeaTow. If you have a
number of electrical loads, its only a matter of time before you wake
up and find the anchor light, plus the TV that you forgot to turn off,
has drained the batteries. So the question becomes, do you need to
start the engine to get back home? I would think that there is some
place you could find to stash a small AGM starting battery that would
greatly reduce this risk.

BTW, one of my "pet peeves" is using an inverter to power a small TV,
when there are plenty of TVs that run on DC more efficiently. You
should read the specs carefully, because many TVs have significant
loads, even when "turned off." For instance, my AC/DC 9 inch
Panasonic draw almost 2 Amps more when powered on AC, and that load
continues simply by being plugged in. This means that you could
inadvertently draw an extra 25 Amp-hours overnight from this alone.

There are other "forgotten" loads to think about. If you run the
propane through a shutoff solenoid, that may draw a half Amp. And if
you run it all night for a heater, you should have leak detector -
another small but constant load.

Jeff wrote in news:tZOdnSDPoNLGL9vfRVn-
:

BTW, one of my "pet peeves" is using an inverter to power a small TV,
when there are plenty of TVs that run on DC more efficiently. You
should read the specs carefully, because many TVs have significant
loads, even when "turned off."

I think now is a good time to bring up the new TV in Lionheart Cap'n
Geoffrey handed me to hook up. It's a MUCH more efficient LCD model, a 19"
flat monster that's only 2" deep. We mounted it on one of those cast
aluminum swivel mounts with the two arms and locking joints around the
corner from her nav station at the bottom of the main hatch to the center
cockpit. Doing this allows us to swing the TV around so it can be used as
a big screen computer monitor for the Dell Latitude notebook that can also
be easily seen from the helm at sea so the watches can monitor their
progress on a bigger screen.

This TV/monitor was delivered with a 12V, 2A power supply dongle with a
cord. As the TV is to be mounted permanently to the boat, I simply cut the
DC cord off the dongle, noting its polarity that wasn't marked on the TV's
DC input jack. I pulled the cable through a hole into the nav station's
communications suite and connected it to one of the permanently-powered DC
fuses so it would always be running off the house DC power. Before
connecting it, I measured its 1.28A load, making it much more efficient
than the old CRT TVs that had such small screens and took up so much shelf
space.

When in port, we simply swivel the TV around to point at the cabin seating
and connect up City Marina's Comcast Cable to the custom cable I installed
into the boat's jammed-up wiring runs. "We can fit another cable in there,
right?".....(c; The cable jack for the dock link is next to the AC power
jacks and the coax is tywrapped to our main power cable.

Having seen it at E-docker's new home on J-dock, I got 4 more boats to
wire, now....for the WIVES!

Sorry I can't remember what brand the TV is but it's an odd brand. Just
read the voltage coming out of the power supply dongle on the LCD TV you're
considering and look for anything from 12-15VDC output from it. The DC
regulators are inside the TVs so it doesn't matter if it's off a few volts.
Runs great off batteries and is very little load to the monsters.

Having watched a surge suppressor explode from the AC line power at City
Marina since we moved, the TV's MUCH safer off hooked to the house
batteries than AC power!

Oh, one word on cable TV......ISOLATOR NEEDED!! Cable TV's shield wire is
hard connected to shore power ground! So, you hook up the TV to the house
batteries and you're connecting SHORE GROUND straight to the house battery
negative leads! Here we go with more galvanic isolator problems. Luckily,
we don't need to have any ground at all on the cable TV, so I've
constructed this really CHEAP galvanic isolator to keep the boat isolated
from cable TV's grounding system.....

coax center wire
--------||-----------
dock .01uF boat
cable 600V TV
--------||-----------
coax ground shield

The caps are disc ceramics and not critical, just as long as they pass
54Mhz up and block 60 Hz and DC, which .01uF does just fine. If your cap
is too small, channels 2-6 may come in snowy as dock signals usually suck.

Voila - Cable TV galvanic isolator. Mine is in a plastic pill bottle with
two F connectors, one on each end, behind the comm station panel....NOT
grounded!

Just read the voltage coming out of the power supply dongle on the
LCD TV you're
considering and look for anything from 12-15VDC output from it.
The DC
regulators are inside the TVs so it doesn't matter if it's off a
few volts.

Bad advice concerning the consumer grade LCD TVs I know of.

The 120 volt AC to 12 volt wall wart *is* the voltage regulator, there
is no DC regulator inside the TV. I called technical support
concerning my Samsung SyncMaster 150mp and they said the voltage must
be a clean 12.3 volts plus or minus 5%. Clean means no high voltage
spikes or significant AC ripple. They said lots of folks are running
this particular monitor in emergency vehiclesetc., but only by using a
10-16v--12v regulated power supply (expensive), *not* connecting
directly to the vehicle's DC bus.

Typical boat voltages range from 10v or so when running heavy loads
like anchor windlasses, to 14.4v or so when charging. High voltages
will burn out the cold cathode fluorescent backlight circuitry, every
time. You either have an unusual LCD TV, never use the TV during the
top end of a 3-step charging cycle, or are just plain lucky.

"Mark" wrote in
ups.com:

You either have an unusual LCD TV, never use the TV during the
top end of a 3-step charging cycle, or are just plain lucky.


I'll get the make/model next time I'm on the boat and post it. Functions
flawlessly, here.

Must depend upon the rig. I've been running a 12V flatscreen Sharp
for 3 years with no problem.

"Mark" wrote in message
ups.com...
Just read the voltage coming out of the power supply dongle on the
LCD TV you're
considering and look for anything from 12-15VDC output from it.
The DC
regulators are inside the TVs so it doesn't matter if it's off a
few volts.

Bad advice concerning the consumer grade LCD TVs I know of.

The 120 volt AC to 12 volt wall wart *is* the voltage regulator, there
is no DC regulator inside the TV. I called technical support
concerning my Samsung SyncMaster 150mp and they said the voltage must
be a clean 12.3 volts plus or minus 5%. Clean means no high voltage
spikes or significant AC ripple. They said lots of folks are running
this particular monitor in emergency vehiclesetc., but only by using a
10-16v--12v regulated power supply (expensive), *not* connecting
directly to the vehicle's DC bus.

Typical boat voltages range from 10v or so when running heavy loads
like anchor windlasses, to 14.4v or so when charging. High voltages
will burn out the cold cathode fluorescent backlight circuitry, every
time. You either have an unusual LCD TV, never use the TV during the
top end of a 3-step charging cycle, or are just plain lucky.