Re: [Paddlewise] VHF battery drain when monitoring.

My question would be not when do the batteries drain to much to keep
monitoring, but when do they drain so much that you have compromized your
own transmit power?

If we assume 70 hours of monitoring before we can no longer monitor, then we
could also assume that transmit power requirements would be compromised much
earlier. This is in part due to the larger current demands which if I
remember correctly would produce a corresponding voltage drop. This would
seem to indicate that on a day trip using alkaline batteries, we could all
monitor, but that on a multi day trip we may have a battery degradation issue.

For what it's worth all of my radios are nicad, but I have a spare battery
pack that is alkaline for one of them, and I bring that on my multi day
trips. And in answer to Daves survey, I only leave mine on when I am on
short day trips or when crossing shipping lanes here in the Pacific NW. On
any of my more remote longer trips (when as a form of any help may be better
than no help) I unfortunatly keep the radios off to save battery life.

Has anyone in the group done any standby drain and then transmit tests at
different temperatures?

-Saul

At 03:40 AM 12/3/98 -0800, Richard Mitchell wrote:
>How long can you listen?  With a little help from ICOM and some
>battery manufactrurers, here is the estimate.  We have little
>excuse for not monitoring because of battery drain unless one is
>limited to nicad (an unfortunate choice for backcountry
>paddling).
> 
>ICOM B3, M7, M9, and M10 and M10a handheld VHF radios all
>discharge 19 milliamp per hour on standby, i.e. with power on and
>squelch turned up just slightly to inhibit static.  Standard AA
>batteries operate in series (additively) so that the 6 batteries
>in an ICOM BP 90 pack produce 9 volts.  Each battery produces 1.5
>volts.  If we presume a "cut off" threshold of 1.2 volts as
>minimum to activate equipment then at 20 degrees centigrade (68
>degrees F), with a constant drain, the batteries will last 70
>hours before the threshold is reached.  At higher temperatures
>(113 degrees F.) drain is more rapid and batteries will reach
>threshold in 30 hours.
>
>For further technical information you may wish to contact Norvac
>Electric, (503) 644-1025 or Micro Power, (503) 626-7086. Also
>Rogers Marine at (503) 287-1101 and ICOM customer service at
>(206) 454-7619 then option #5.
>
>RGM
> 
>Richard G. Mitchell, Jr.
>Department of Sociology
>Oregon State University
>Corvallis, OR 97331
>U.S.A.
>(541) 752-1323 phone/fax
>mitchelr_at_ucs.orst.eduMessage-ID: <3666765C.47DF31B5_at_ucs.orst.edu>
>Date: Thu, 03 Dec 1998 03:30:36 -0800
>From: Richard Mitchell <mitchelr_at_ucs.orst.edu>
>X-Mailer: Mozilla 4.04 [en] (Win95; U)
>MIME-Version: 1.0
>To: Richard Mitchell <mitchelr_at_ucs.orst.edu>
>Subject: Batery
>Content-Type: multipart/mixed; boundary="------------DE5FC531F4E0E0145F5E61FC"
>
>-- 
>Richard G. Mitchell, Jr.
>Department of Sociology
>Oregon State University
>Corvallis, OR 97331
>U.S.A.
>(541) 752-1323 phone/fax
>mitchelr_at_ucs.orst.eduBATTERY
>
>ICOM M7, M9, M10 all discharge 19 milliamp per hour on standby, i.e. with
power on and squelch turned up just ®MDUL¯slightly®MDNM¯ to inhibit
reception.  Standard AA batteries operate in series (additively) so that the
6 batteries in a the BP 90 pack produce 9 volts.  Each battery produces 1.5
volts.  If we presume a "cut off" threshold of 1.2 volts as minimum to
activate equipment then at 20 degrees centigrade (68 degrees F), with a
constant drain, the batteries will last 70 hours before the threshold is
reached.  At higher temperatures (113 degrees F.) drain is more rapid and
batteries will reach threshold in 30 hours.  
>
>Contact Norvac Electric, 644-1025 for fresh batteries and Micro Power,
626-7086 for excellent technical wholesale information.  Also Rogers Marine
at (503) 287-1101 and ICOM customer service at (206) 454-7619 then option
#5.        
>
>
Saul Kinderis     saul_at_isomedia.com          tel:(425)402-3426

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