Clueless in (not Seattle) Amps, etc.
 

On Jul 27, 2:40 pm, Skip Gundlach wrote:
..
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.

stuff snipped

Hi Skip,

This is what I'd do:

"For those who know a bit about electrics and can use a hydrometer I
would propose:

Do an energy budget/audit.

Size the battery bank for 40% DoD (depth of discharge) on a normal
days/period of use

Use the hydro to verify the above a few times as well as check the
batts are getting fully charged.

Use the hydro to check a few times that an exceptional days/period of
demand doesn't draw the batts below 80% DoD"


If you do the above why not write it down as well as charging times
etc in a log and post it.

I'd keep the solar/wind for now, just treat it as 'gravy' to stretch
the time between charging or reduce the charging time.

I won't say the above is the full solution, but is a worthwhile
learning exercise. There's probably some more advanced stuff to learn
but you have to do the basics first.

Any comments from other people?

cheers,
Pete.

Clueless in (not Seattle) Amps, etc.
 

Since refrigeration is probably your largest consumer of power, and most
people don't *really* know how many hours a day their system runs, I would
suggest that you get a 12V run-hour meter and wire it into your system.
Log how many hours it runs and keep that in a spreadsheet and calculate how
much power you're using on a daily basis.

I do this and it lets me know how well the system is working and points out
any potential problems which may be forming. Since I designed and built my
system, I also have a tendancy to play with the expansion valve settings
and thermostat set-points. This allows me see how the changes have
effected the performance. I tend to go a bit overboard and keep track of
both the refrigeration and freezer run hours.

-- Geoff

Clueless in (not Seattle) Amps, etc.
 

On Jul 27, 6:40 am, Skip Gundlach wrote:

Perhaps I'll just have to learn to live on less than 200AH/day,


OH MY GOD !


Skip, you need either:

1) **** can everything: solar, wind, humongous dueling alts and get
one good gen set.

OR

2) walk the streets. find some peyote buttons or lsd and go on a
vision quest. A significant paradigm shift is in order.


Bob

Amps, etc.
 

Wayne.B wrote in
:

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.


Maybe this is what we need......(c;
http://www.fleetsource.com/Alternator_p/4900j.htm

Will a 4 cyl 4-154 Perkins turn it and the prop simultaneously, or will we
have to wait for the batteries to come up before coming out of neutral on
the tranny??

Larry
--
While in Mexico, I didn't have to press 1 for Spanish.
While in Iran, I didn't have to press 1 for Farsi, either.
While in Florida, I had to press 2 for English.
It just isn't fair.

Amps, etc.
 

On Fri, 27 Jul 2007 07:55:55 -0400, Wayne.B
wrote:

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.
That is analagous to using a flowmeter in your fuel line to drive your
speedometer (via a lookup table) ;-)
A shunt is used to measure current as you well know.
The Magic box that looks at the shunt counts in and out then
"guesstimates" based upon a number of parameters set by the installer
that may be right or may be wrong at that point in the banks life. The
final result is therefore ????? However most with amp counters assume
the numbers are gospel!

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.

Granted (maybe) but the "average" boater has no idea what load is on
at the time, and the average boater feels everything is OK if he sees
12.00 volts!

How do you explain the real life discrepancy between units as
discussed in my original post? The amp counter was WRONG!
Oh and by the way try leaving an amp counter on a battery with no load
for 6 months and see if it reads the correct information! No amps out,
no amps in, bank is 100% !!! is it hell!

--
Richard

Nb "Pound Eater" Parkend G+S
"Governments are like Nappies, they should be changed often."
(For the same reason)

Clueless in (not Seattle) Amps, etc.
 

Skip Gundlach wrote:

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%.

Wet cell batteries are a very mature technology.

The rules for them are very simple.

1) If you want to consume 200AH/day, you must generate 250AH/day of
replacement energy.

You can play all kind of regulator games, but in the end, the overall
average replacement rate is about 15% of the bank capacity or in this
case, 15%(750)=112.5A.

The minimum recharge time will be: 250/112.5=2.2 hours.

How you choose to get it done is your business, but the above rules
define the task.

Solar:

For an engineering estimate, use a 2ftx4ft,80W panel which translates
into 10W/sq ft.

Derate 50% for dirt, clouds, angle of attack, etc, thus 5W/sq ft.

As a year around average use 12 hours/day, thus 12hours(5W/sq ft))=60
watt-hours/sq ft/day.

60watt-hours/12volts=5amp-hours/sq ft/day.

To generate 250AH of solar you need 250/5=50sq ft or at least 7
2ftx4ft panels.

Probably not going to happen unless you build a hard bimini so you
have a place to plant your solar garden.

That's why alternators like the L/N 4800/4805 family exist.

Modest size, only 145/165 output depending on model, but either
deliver in excess of 100A at 2,000 alternator.

Ya pays ya money, ya takes ya pick.

Lew

Amps, etc.
 

"Electricky Dicky" wrote in message
...
A shunt is used to measure current as you well know.
The Magic box that looks at the shunt counts in and out then
"guesstimates" based upon a number of parameters set by the installer
that may be right or may be wrong at that point in the banks life. The
final result is therefore ????? However most with amp counters assume
the numbers are gospel!

snippage

--
Richard

Nb "Pound Eater" Parkend G+S
"Governments are like Nappies, they should be changed often."
(For the same reason)

So it really comes down to choosing your choice of "magic boxes" which
"guesstimate"? How is the Smartguage better than the Link 10, if they both
"guesstimate" the state of charge?

Amps, etc.
 

On Thu, 26 Jul 2007 10:23:19 -0700, Pete C
wrote:

On Jul 26, 4:29 pm, Stephen Trapani wrote:
Can't a person extrapolate state of charge with a simple voltmeter?

Good point, you can, with a few caveats which are covered by the
battery FAQ I posted a link to.

I'd probably use the voltmeter as a rough and ready guide on a day to
day basis, and a hydro now and then to verify it.

Cross referring the two could be pretty useful.

This is a wireless SG sensor setup.
Data can be fed to a PDA, laptop or desktop and crunched
by the relevant software for analysis.
http://www.electrosense.com.au/SG-Electrode.htm
Toss out those old hydrometers.
You can probably get a nice setup of these for less than $10k.
Agitator beds for the batteries could be added if desired, but
I haven't looked for them. If I ordered any of this stuff I would
want a couple pocket protectors thrown in gratis.

--Vic

Amps, etc.
 

On Jul 27, 10:06 pm, Vic Smith
wrote:
This is a wireless SG sensor setup.
Data can be fed to a PDA, laptop or desktop and crunched
by the relevant software for analysis.http://www.electrosense.com.au/SG-Electrode.htm
Toss out those old hydrometers.
You can probably get a nice setup of these for less than $10k.
Agitator beds for the batteries could be added if desired, but
I haven't looked for them. If I ordered any of this stuff I would
want a couple pocket protectors thrown in gratis.

LOL!

For checking SG under way a refractometer might be easier, on the
pocket at least! eg:

http://cgi.ebay.com/Battery-Acid-Ant...lycol-Coolant-
Refractometer-
F_W0QQitemZ230154976520QQihZ013QQcategoryZ111537QQ ssPageNameZWDVWQQrdZ1QQcmdZViewItem

cheers,
Pete.

Amps, etc.
 

On Fri, 27 Jul 2007 14:25:53 -0700, Pete C
wrote:

On Jul 27, 10:06 pm, Vic Smith
wrote:
This is a wireless SG sensor setup.
Data can be fed to a PDA, laptop or desktop and crunched
by the relevant software for analysis.http://www.electrosense.com.au/SG-Electrode.htm
Toss out those old hydrometers.
You can probably get a nice setup of these for less than $10k.
Agitator beds for the batteries could be added if desired, but
I haven't looked for them. If I ordered any of this stuff I would
want a couple pocket protectors thrown in gratis.

LOL!

For checking SG under way a refractometer might be easier, on the
pocket at least! eg:

http://cgi.ebay.com/Battery-Acid-Ant...lycol-Coolant-
Refractometer-
F_W0QQitemZ230154976520QQihZ013QQcategoryZ111537Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem

So many gadgets, so little time.

--Vic