In article ,
Stephen Trapani wrote:

Pete C wrote:
On Jul 26, 3:52 pm, "KLC Lewis" wrote:

It takes me about 10 - 15 minutes to check all of the cells in my bank.
This
is with the boat sitting calmly at the dock. I would much prefer not to
have
to open those cells with the boat in motion, sloshing battery acid around.
If a meter will give me reasonably accurate information, which I can
verify
from time to time with a physical check of the electrolyte when it can be
done safely, so much the better.

Well, buy a Smartguage then!

Can't a person extrapolate state of charge with a simple voltmeter?

Stephen

It can be done, IF you have charactorized you battery cells before hand,
and have a good running record of SG vs Voltage on a per cell basis.
Other than that you just "Guesstimating", and that is about as accurate
as a DartBoard.......

Bruce in alaska
--
add a 2 before @

Skip Gundlach wrote:


We have as a target of never letting our batteries get below 75% - and
only rarely below 90%.

Trying to get the recharge above 90% will require a lot of time and
vaporize a lot of electrolyte.

Consider cycling between 70%-90%.

Much easier to accomplish with less wear and tear on the equipment.

Our solar and wind were calculated to provide somewhere between 150
low and 300 high AH/Day on average. Continuously cloudy (well,
raining - it was completely overcast here at 5 and we were still
getting 12A from the solar), windless days will throw that off, of
course. However, we watch that meter like a hawk, and having had a
bit of training about the interface of volts and amps as to what's
happening in there, believe we'll be better managers than before.

Not a fan of wind, far too much noise. Much prefer solar and so will
your neighbors in an anchorage.

Unless you can mount at least 100 sq ft of solar, you are still going
to need a good alternator.

Do yourself a favor.

Get a copy of the performance curve (AMP v RPM) for your unit and
check the output @ 3,000 alternator RPM.

This should be the "hot" not the "cold" rating curve.

If it is the "cold" rating, deduct 20%.

You can now get a handle on your energy audit.

Without an honest alternator output value, you are flying blind.

However, as backup, but aboard
for our use of power tools in strange countries, as well as our hookah
rig, we have a 2000w Honda much bruited about here on other
occasions. Were it necessary while on the hook, likely we'd start
that before the diesel, solely for charging.

No comment.

Keep in mind a dedicated 10W solar panel will keep the starting
battery charged.

No need to make life complicated.

Lew

On Thu, 26 Jul 2007 00:17:18 +0000, Larry wrote:

(Richard Casady) wrote in
:

It is, or used to be, the practice on submarines.

Naw.....We check on the control rods, now....(c;

Actually the nuke boats have a battery, and, to charge it an engine
half the size of the four in a WWII boat. Something to get the reactor
started after a shutdown. Able to push the boat maybe three knots.
There is a retractable electric motor, maybe 300 horsepower worth.

Casady

On Thu, 26 Jul 2007 01:51:23 -0000, Skip Gundlach
wrote:

We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input. But if we don't put in the charge,
eventually the biggest battery bank will be flat, even if nothing is
drawn from it, out of normal charge dissapation (flooded = ?%/
month)...

To recharge 750 AH in a reasonable length of time you need a 3 stage
charging source of 150 to 200 amps (25% of capacity). Don't let Larry
tell you anything different. Wiring of appropriate size is also
required of course.

If you had a generator you could do that the way we do - use the
charger half of a high powered inverter/charger. Since you don't, you
will need a seriously high powered alternator with an external
regulator. An alternator of 200 amp capacity will typically be a
large frame Leece-Neville, require two drive belts, and quite possibly
some custom work on your engine drive sheaves and alternator mount.
All of this is not cheap of course, and it will take some shopping
around just to find someone qualified to do the work. Nothing less is
going to get the job done however.

On Thu, 26 Jul 2007 03:35:18 -0000, Skip Gundlach
wrote:

We have as a target of never letting our batteries get below 75% - and
only rarely below 90%.

That is unrealistic. It takes too long to charge batteries above the
80 to 90% level because charging current must be tapered down.

Much more realistic is to run your batteries between 50% and 80%. That
requires a good 3 stage charging system capable of supplying 25% of
your capacity during the bulk charge stage.

Wayne.B wrote in
:

On Thu, 26 Jul 2007 01:51:23 -0000, Skip Gundlach
wrote:

We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input. But if we don't put in the charge,
eventually the biggest battery bank will be flat, even if nothing is
drawn from it, out of normal charge dissapation (flooded = ?%/
month)...

To recharge 750 AH in a reasonable length of time you need a 3 stage
charging source of 150 to 200 amps (25% of capacity). Don't let Larry
tell you anything different. Wiring of appropriate size is also
required of course.

If you had a generator you could do that the way we do - use the
charger half of a high powered inverter/charger. Since you don't, you
will need a seriously high powered alternator with an external
regulator. An alternator of 200 amp capacity will typically be a
large frame Leece-Neville, require two drive belts, and quite possibly
some custom work on your engine drive sheaves and alternator mount.
All of this is not cheap of course, and it will take some shopping
around just to find someone qualified to do the work. Nothing less is
going to get the job done however.

And don't forget cooling. A 200A alternator is going to generate a lot
of heat and will need to be cooled. You just can't throw it into an
enclosed engine space and expect it to crank out 200A without burning
up. You need to have a 3 stage controller with a thermocouple on the
alternator and you need to pipe air into the engine space.


-- Geoff

On Fri, 27 Jul 2007 05:21:01 -0500, Geoff Schultz
wrote:

And don't forget cooling. A 200A alternator is going to generate a lot
of heat and will need to be cooled. You just can't throw it into an
enclosed engine space and expect it to crank out 200A without burning
up. You need to have a 3 stage controller with a thermocouple on the
alternator and you need to pipe air into the engine space.

Good points. In the end you may find that a generator coupled to an
inverter/charger has a lot to recommend it.

On Thu, 26 Jul 2007 12:55:16 -0500, "KLC Lewis"
wrote:

I don't find anything on
the Smartguage site that says how their meter can do it without a shunt, and
with only two wires connected directly to the battery bank.

It can't of course, it can only guesstimate. If you want to measure
something you need the proper tools. The tool in this case is a
shunt.

On the other hand you can argue that all that is really needed is a
digital voltmeter to approximate state of charge. If your batteries
are reading 12.6 volts under a light to moderate load, they are at
100%. Dropping down to 11.6 volts under the same conditions, they are
at 50% and need to be recharged immediately.

On Jul 26, 11:49 pm, Wayne.B wrote:
On Thu, 26 Jul 2007 01:51:23 -0000, Skip Gundlach

wrote:
We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input. But if we don't put in the charge,
eventually the biggest battery bank will be flat, even if nothing is
drawn from it, out of normal charge dissapation (flooded = ?%/
month)...

To recharge 750 AH in a reasonable length of time you need a 3 stage
charging source of 150 to 200 amps (25% of capacity). Don't let Larry
tell you anything different. Wiring of appropriate size is also
required of course.

If you had a generator you could do that the way we do - use the
charger half of a high powered inverter/charger. Since you don't, you
will need a seriously high powered alternator with an external
regulator. An alternator of 200 amp capacity will typically be a
large frame Leece-Neville, require two drive belts, and quite possibly
some custom work on your engine drive sheaves and alternator mount.
All of this is not cheap of course, and it will take some shopping
around just to find someone qualified to do the work. Nothing less is
going to get the job done however.

I'm obviously missing a great deal of intelligence here.

I had thought we'd properly sized our bank and input sources to allow
for our anticipated usages.

Obviously I was mistaken; I need a large-frame alternator and the
appropriate drive components, in order to only bring my bank to 90%.

Instead, I'm inputting, over an entire day, unless they're already
full, in which case the controllers either divert or disconnect the
load, on average, somewhere between 150 and 300AH, an average (varies,
of course) of 6-12A per hour. Obviously, that's inadequate to keep a
battery topped up, especially a big one.

Trickling it in, I'd expected to rarely stress my batteries, rather
than subjecting it to high inputs for short times, and to, for the
most part, keep them full. I see I'm mistaken and must put not less
than 100A into the battery bank any time I'm charging, and must make
time in my schedule to run the main engine at least often, if not
regularly.

My 370W of solar, and KISS wind generator, are taking waaaay too much
room on the arch considering they're doing nothing to enhance my
charging regime. I figure I can save at least 100 pounds off the load
on the stern if I ditch them. Where I am, right now, in Charleston SC,
at 9AM, I'm only making 10 solar Amps with a bank which reads 13.9.
Yesterday, at 5:30, when I turned off the outside power and fired up
the inverter and put everything I could find on the load, it only was
making 20A. Controllers apparently size the output to the load (?).
I wonder what it would do at noon with a load?

I have no idea what it will do in real-world situations. I've only
seen 25A at the dock, sometimes, and 30A from the wind, but today's
dead calm, so there's nothing there.

Perhaps I'll just have to learn to live on less than 200AH/day, and
buy one of those massive alternators. Damn. I thought I was finished
in the engine room for a while. Oh, well. My 360CFM air exchange
ought to make it a little less stifling in there

Oh, and, of course, never leave the dock, as to do so would be to
surrender to a schedule. After all, if you get somewhere, sometime,
you've fulfilled *some* schedule, even if it wasn't something
targeted. But since I but since I can ill-afford the prices in any
marina, let alone this one, we'll have to do it from the hook, which
is ok, too. I just wish I'd get to see more places...

I'm going to cast caution to the winds today and go out for a sail, to
seatrial our repairs. However, we'll return to the security of the
dock this afternoon. We might play tourist for a while here, but we'll
have to do it from the hook, having exhausted the excuses to be at a
dock, not requiring any outside mechanics' assistance.

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.google.com/group/flyingpiglog and/or
http://groups.yahoo.com/group/TheFlyingPigLog

"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in its
hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)

Skip Gundlach wrote in
ps.com:

On Jul 26, 11:49 pm, Wayne.B wrote:
On Thu, 26 Jul 2007 01:51:23 -0000, Skip Gundlach

wrote:
We've already got massive batteries. The issue is properly keeping
them charged. At 750 nominal (less aging) AH, we can go for a long
time with no charge input. But if we don't put in the charge,
eventually the biggest battery bank will be flat, even if nothing is
drawn from it, out of normal charge dissapation (flooded = ?%/
month)...

To recharge 750 AH in a reasonable length of time you need a 3 stage
charging source of 150 to 200 amps (25% of capacity). Don't let
Larry
tell you anything different. Wiring of appropriate size is also
required of course.

If you had a generator you could do that the way we do - use the
charger half of a high powered inverter/charger. Since you don't,
you
will need a seriously high powered alternator with an external
regulator. An alternator of 200 amp capacity will typically be a
large frame Leece-Neville, require two drive belts, and quite
possibly
some custom work on your engine drive sheaves and alternator mount.
All of this is not cheap of course, and it will take some shopping
around just to find someone qualified to do the work. Nothing less
is
going to get the job done however.

I'm obviously missing a great deal of intelligence here.

I had thought we'd properly sized our bank and input sources to allow
for our anticipated usages.

Obviously I was mistaken; I need a large-frame alternator and the
appropriate drive components, in order to only bring my bank to 90%.

Instead, I'm inputting, over an entire day, unless they're already
full, in which case the controllers either divert or disconnect the
load, on average, somewhere between 150 and 300AH, an average (varies,
of course) of 6-12A per hour. Obviously, that's inadequate to keep a
battery topped up, especially a big one.

Trickling it in, I'd expected to rarely stress my batteries, rather
than subjecting it to high inputs for short times, and to, for the
most part, keep them full. I see I'm mistaken and must put not less
than 100A into the battery bank any time I'm charging, and must make
time in my schedule to run the main engine at least often, if not
regularly.

My 370W of solar, and KISS wind generator, are taking waaaay too much
room on the arch considering they're doing nothing to enhance my
charging regime. I figure I can save at least 100 pounds off the load
on the stern if I ditch them. Where I am, right now, in Charleston SC,
at 9AM, I'm only making 10 solar Amps with a bank which reads 13.9.
Yesterday, at 5:30, when I turned off the outside power and fired up
the inverter and put everything I could find on the load, it only was
making 20A. Controllers apparently size the output to the load (?).
I wonder what it would do at noon with a load?

I have no idea what it will do in real-world situations. I've only
seen 25A at the dock, sometimes, and 30A from the wind, but today's
dead calm, so there's nothing there.

Perhaps I'll just have to learn to live on less than 200AH/day, and
buy one of those massive alternators.

You had better learn to live on 200 AH or less if you're going to stay
on a hook! You can have the biggest battery bank around, but if you
can't keep them charged, they won't do you any good. I'd rather have a
much smaller bank that I keep charged rather than a huge bank that's
undercharged.

Solar panels are great if you're somewhere that has lots of sun. I
personally de-rate the panels to 1/2 of their listed wattage to come up
with the *maximum* that I'll see out of them. This is 11 AM - 1 PM sun
and then it falls off before/after that. As the batteries climb in
voltage, you'll see less and less wattage.

Wind is great if you're somewhere that's windy. Summer on the dock in
Charleston doesn't fit that bill. The Bahamas or Caribbean quite often
does. I personally would rather spend $ on wind generators rather than
solar as I feel that you get a better bang for the buck. The wind can
blow for 24 hours, but at best you get 6 hours of good solar generation
without sun-following panels.

On BlueJacket we use about 150-200 AH a day. Refrigeration takes up the
bulk of that at about 85 AH. Replacing all of our incandescent lights
with LED based lights really helped save power. The rest of the power
goes into stuff like making water (about 40 AH), running the computer to
get weather faxes, stereo, watching DVDs on the TV, etc.

Whatever power I don't generate via my solar panels or wind generator, I
make up via the generator powered ProSine inverter/charger. (Note that
I wouldn't recommend ProSine as I've had to replace the unit too many
times.) I don't want to run the engine to charge the batteries as I
don't like to run the engine under light loads and I like to reserve
engine hours to moving the boat.

So you're right where most cruisers are when they find out that they're
power hungry and their generation doesn't match their consumption. The
easiest thing to do is to cut back on the usage, but that only goes so
far. Good luck balancing things. It takes a while to figure it all
out.

-- Geoff
www.GeoffSchultz.org