All about batteries, battery monitors, battery using appliances and charging

jerry work

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Feb 3, 2003
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A while back I did presentations atGMC rallies discussing the selection and wiring of many things on the 12vdc house systems that should answer many of your questions. The presentation can be downloaded from GMCMI, GMCWS, GMC Cascader, GMC 49er and perhaps other GMC club web sites. Lots to consider here as all things are interconnected and changing one may well effect the others. A true shunt based battery monitor is the only way to really tell how much usable capacity you have left in your battery bank and how long it will take to recharge it whether you are using shore power, a generator and/or solar. Battery voltage is only a WAG at best.

Jerry Work
The Dovetail Joint
Fine furniture designed & hand crafted
in the 1907 former Masonic Temple building
in historic Kerby, OR
http://jerrywork.com
 
Do you refer to what I call an 'Ammeter'? :)

-johnny

--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
"I forgive them all, save those who hurt the dogs. They must answer to me in hell" - ol Andy, paraphrased
 
An ammeter is a device that measures the amount of current flowing through =
a wire at any given time. It tells you little about how much current has g=
one into or has come out of the battery bank over time. That is what you n=
eed to know to monitor usage. The device that does that is called a batter=
y monitor. While they come in several forms, the type you want for a GMC i=
s based on a shunt. That is a precision resister that is connected between=
the negative terminal of your battery bank and all grounds. As current is=
used to power different appliances and lights in your coach the battery mo=
nitor accumulates that useage over time and compares it to the capacity of =
your battery bank. A display on the monitor will show you how much went in=
to the battery bank from any charge source, how much came out of the batter=
y bank from any use and how much battery capacity is left. Most monitors s=
how many other parameters as well, but this is the critical information you=
need. Be sure the shunt is wired so ALL grounds connect to one side of th=
e shunt and the other side connects directly to the negative terminal on yo=
ur battery bank. The shunt is the only thing that should be connected to t=
he negative terminal. Jerry Jerry & Sharon Work Kerby, OR glwork=
@mac.com http://jerrywork.com Prevost Country Coach Formerly 7=
8 Royale with most everything done to modernize a GMC mechanically 77/94 =
Clasco that looked like it just left the Clasco facility. Loved them both.=
Message: 3 Date: Fri, 01 Mar 20=
19 13:46:54 -0700 From: Johnny Bridges To: gmclis=
t Subject: Re: [GMCnet] All about batteries, battery moni=
tors, battery =09using appliances and charging Message-ID: Content-Type: text/plain; charset "utf-8" =
Do you refer to what I call an 'Ammeter'? :) -johnny -- Foo=
lish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Brase=
lton, Ga. "I forgive them all, save those who hurt the dogs. They must a=
nswer to me in hell" - ol Andy, paraphrased