[Icom] Battery Operation

Fri, 13 Jun 2003 21:21:49 -0400

Hi to Bill and Rick,
I've made a serious study of large capacity batteries over the last 5 or so
years, being a cruising sailboat owner so I just thought I'd share a couple
of thoughts:
When an acid or the AGM batteries show you 12 volts after being at rest for
12 hours (or very low amperage draw) they are at ABOUT 50% discharge (or 50%
charge if you want to look at the half full view point :)

That 12.9 voltage for AGMs is a long term float voltage.  If you want to get
it ready for peak operation, it should be bulk charged using 14.38 volts
until its 90% charged, dropping to an absorbtion rate of  14.18 volts for
the final 10%. with a float voltage of  13.38.  We have a programmable
charge controller (Balmar) and a "smart charger" (Truecharge) which both
monitor the rate of voltage rise during the charge process and use these
voltages to transition through these stages.

When we installed the Lifelines (a couple of 4d units) we talked to the
people at Lifeline (Concord actually) and verified these numbers.

Anyway, the key is the charger. A plain old car battery charger tapers down
so quickly, they usually don't give batteries their capacity.

RE Rick's point - I'll second that question. I've always favored ICOM gear
but when I selected a marine VHF radio, one of the parameters I compared was
the output wattage at reduced voltage.  Another brand (Standard which is
Yaesu) did much better at putting out the full power under reduced voltage
conditions.

73's
Tom

----- Original Message ----- 
From: "Clifford, Rick" <[email protected]>
To: <[email protected]>
Sent: Friday, June 13, 2003 5:54 PM
Subject: RE: [Icom] Battery Operation

I just bought a Lifeline GPL-24T for portable operation with my IC-746.
Fully-charged, this 80 Ah battery puts out about 12.9V. I used it quite
successfully (with a very limited amount of discharge) on a hilltopping
operation running for about 3 hours at 50W.

But I run only CW so I guess no problem.

I wonder why the radio manufacturers don't design their units to operate in
a 12-14V range?

73,

Rick

-----Original Message-----
From: William Lambing [mailto:[email protected]]
Sent: Friday, June 13, 2003 2:31 PM
To: Icom Reflector
Subject: [Icom] Battery Operation

The problem with battery operation is:

What is the output voltage?

Is it 12V or 13.6/13.8V?

Many radios sound absolutely horrible at 12V.  Some shut down, some start to
FM...and on and on.  Listen to Midcars or ECARS someday while some of these
guys, mobile, with the engine shut off attempt to contact someone.  95% of
the time, they are completely unreadable.  Now if you run CW...then all bets
are off..!  This mode usually works just great.  It is the SSB peak output
that gets you in trouble.  Sometimes you can cut the power down to 50W and
things are ok.....for a while until the 12V gets lower and lower..!

Using a charger whilst operating on batteries, introduces hum from the
charger.

73

Bill, W�LPQ

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Your Moderator: Dick Flanagan W6OLD, [email protected]
Icom Users Net: Sundays, 1700Z, 14.315 MHz
Icom FAQ: http://www.qsl.net/icom/