K1 Battery Question

[John J. Bahun]

I have a 4 Amp Hour Gel Cell pack that I just acquired.  I was wondering if anyone has any input as to how long I should expect the K1 to operate off this battery with typical transmit behavior (Not sure exactly what that is...)

Thanks

JB - WB8UFA / 7


Arguing with an engineer is like wrestling with a pig in mud.
After a while, you realize the pig is enjoying it.

John J. Bahun
Senior Software Engineer
1286 West Crystalline Way
Oro Valley AZ  85737
(520)-219-9514 (Home)
(520)-547-2584 (Work)
(520)-349-8850 (Cell)

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[John Lonigro]

John:

Here's my guess:
1) Measure the receive current in Amps (Ir).
2) Measure the transmit current at the power level you plan to operate,
in Amps (It).
3) Estimate your transmit duty cycle, which will usually be quite a bit
less than 50%.
4) Compute average current drain (I).
    Assuming a 40% duty cycle, your average current drain (I) would be
0.6 x Ir +  0.4 x It
5) Divide 4  Amp Hrs by your average current drain and that will give
you an estimate of your time with the battery.

I don't have a K1, but the spec says as little as 55 ma on receive, so
assume 60 ma (0.06 Amps).  If your transmit current is 1.0 Amp, then
with a 40% transmit duty cycle (probably high), your average current
drain would be 0.6 x .06 + .4 x 1.0 or 0.44 Amps.  With those
assumptions, your fully charged 4.0 Amp Hr battery should last about
4.0/.44 or 9 hours.  A 40% duty cycle might be equivalent to continuous
heavy operating during a contest.

John AA0VE

John J. Bahun wrote:

>I have a 4 Amp Hour Gel Cell pack that I just acquired.  I was wondering if anyone has any input as to how long I should expect the K1 to operate off this battery with typical transmit behavior (Not sure exactly what that is...)
>
>Thanks
>
>JB - WB8UFA / 7
>
>  
>

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[g3ymc]

On 12 Jun 2004 at 4:01, John J. Bahun WB8UFA/7 wrote:

> I have a 4 Amp Hour Gel Cell pack that I just acquired.  I was
> wondering if anyone has any input as to how long I should expect the
> K1 to operate off this battery with typical transmit behavior (Not
> sure exactly what that is...)

I cannot comment on the K1 but for the past two years we have powered
our K2 in RSGB NFD off 4AH Gel Cells. Running at 5W output one gel
cell will easily power the rig for well in excess of 6 hours We used
2 of these cells to cover our 12 hours of operating time and they
were far from flat at the end. The only reason we swapped cells
halfway through was to get rid of the annoying 'Lo Batt' beep which
is a little too conservative with its threshold level. The K1 should
last quite a lot longer.

Incidentally GW4ALG entered the Battery Management Challenge in last
year's NFD using 8 AA alkaline cells and operated for around 6 hours
at 1W level - he had to give up when it became too dark to see, while
there was still plenty of life in the batteries!

This year in NFD we used 7AH cells at the 10W level with the same
experience - see http://www.g4bra.org.uk/nfd04.htm.

73 Dave G3YMC

http://www.davesergeant.com

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