KFØUR's Homebrew QRP Solar Charger

Here is the Shel Radin - KFØUR - QRP Solar Powered Smart Battery Charger Project which keeps his 12V 2A Gel Cells topped off while hiking with his Elecraft KX-1

Shel built this custom QRP Solar Charger using A & A Engineering model 150-PCA assembled Smart Charger circuit board various homebrew components.

The enclosure is a tin he received a retail gift card in and had laying around. Worked pretty well for this application.

The entire assembly, including output fuse holder and all interconnects, weighs only 4 oz.

Final updates: because of low height enclosure,
the output fuse holder was changed to inline
and electrolytic capacitor mounted off board

Shel uses a Watt's Up digital meter to see the instantaneous voltage and charging current . The large, clear plastic case houses the 12V 2A gel cell

The solar panel is a Powerfilm Solar 12V 5W flexible unit

Shel commented: I used it in earnest last weekend for the Adventure Radio Society's "Flight of the BumbleBee" contest. A 4 hour contest where I hiked to the top of Mt. Herman in Monument Colorado (9054 ft elevation). It worked FB, as expected! The whole thing weighs only 4 oz and between the sun and the smart charger, my battery voltage stayed above 13V for the entire 4 hours of operating.


A & A Engineering 7970 Orchid Drive, Buena Park, CA 90620-1930
Phone (714) 952-2114 FAX (714) 994-1104

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