[aprssig] RE: TH-D7AG Battery life

Herb Gerhardt hgerhardt at wavecable.com
Wed Mar 2 00:20:25 CST 2005

Since Dave asked, I did a test for the last 24 hours and obtained the
following result.  I think these results are worthwhile posting on the
several of the SIG's for general information.

I set my TH-D7A (original version) with a fully charged 4 year old well used
W & W Manuf. HC-035W1M-PB39, 1000 mAh 9.6 V NiMh battery.  I ran it on High
power transmitting every 2 min as an APRS tracker.  I had the other band
(bottom band) turned OFF.  I then used my local packet frequency rather than
APRS frequency so that I did not flood our already busy APRS network with
too many packets.  I ran WinAPRS on my computer mainly as a timer.  My
WinAPRS time interval was set at 530 sec to keep from adding needless
packets on that frequency.  The radio transmitted into its stock rubber
duck.  Now the only station that would hear me were the ones who I could
reach on simplex and my signal could not be digipeated.  I doubt that anyone
besides my home station heard me.

Anyway, my WinAPRS recorded receiving a total of 550 packets from my TH-D7A
during the next 19 hours and 5 minutes.  At that point it was still
attempting to transmit for the next hour but the power level was now too low
for my computer to pick it up.  The radio began beeping after about 20 hours
but like I said, the last hour it was no longer useful as a tracker.  I
checked the battery meter once in a while by keying up the radio and
watching the deflection.  The last time I checked it that way was after 12
hours of transmitting and it still displayed full deflection on the meter at
that time.

So the bottom line is:	For SAR use the TH-D7A makes a fine tracker and can
be used all day as a tracker on a SAR team.  I can't speak for the stock
Kenwood NiCd battery, since I have not used them in years and was never
impressed by their performance.

I had intended to repeat this test with my 2 year old battery but since the
results with the 4 year old battery exceeded a full days tracker use, there
was no need to conduct any additional tests.

Herb, KB7UVC
NW APRS Group, West Sound Coordinator
Our WEB Site:  http://www.nwaprs.org

My NEW Email Address:  hgerhardt at wavecable.com

> -----Original Message-----
> From: DaveN roadfacts.com [mailto:dave at roadfacts.com]
> Sent: Monday, February 28, 2005 7:30 PM
> To: hgerhardt at wavecable.com
> Subject: TH-D7AG Battery life
> Herb,
> If you are running your Kenwood at full power (5.5watts) and transmitting
> your position every minute, how long will your battery last?
> Dave W7PDQ

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