[Elecraft] K2 & Solar Power

Mon Apr 28 10:23:00 2003

Lynn,
I operated my K2 on solar power last year during FD.  Not ever desiring a 
battery accident of any kind while mounted inside my K2, I used 2 external 
SLA batteries rated 12 V at 7aH.  External batteries also permit me to 
experiment with varying combinations of batteries as well as makes it easy 
to swap batteries while operating.  One can correctly argue that with two 
batteries of this size and a K2, no charger was needed for the FD 
period.... however, I was interested in the solar power process, so I 
proceeded.

One battery was placed on charge while I operated from the other.  Charge 
controller used was the Micro M+:
        http://www.seslogic.com/microm%2B.html
although the offering from Don Brown here on the list looks like another 
excellent alternative.  Some charge controllers generate undesirable RF 
hash noise.  Neither of these designs do!  If your panel is small enough 
in proportion to your battery capacity, you could probably get by without 
a charge controller, but I liked the idea of a device that would monitor 
charging battery terminal voltage and essentially throttle back the 
charging process to prevent overcharging.

I placed the battery, charge controller, and panel in the sun away from 
the operating position (we operated in the shade).  Wiring was done with a 
series of leads with alligator clip ends.  I used a Unisolar USF-5 
flexible solar panel.  This is a 5 watt panel purchased from:
        http://www.mrsolar.com/panels/unisolar.htm

While my setup is not particularly elegant, it worked!
GL & 73,
Steve
aa8af

[email protected]
Sent by: [email protected]
04/27/2003 10:52 AM

        To:     [email protected]
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        Subject:        [Elecraft] K2 & Solar Power

With Field Day approaching, I'm considering setting up a solar power 
configuration for my K2.  Anyone have any suggestions on how to proceed?

73,
Lynn, K5AVJ
K2 #1411