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)