I am an electrical by trade and researched the equipment available for remote 12vdc applications.
It's possible that I missed something but I spent lots of time and searched a bunch of catalogs.
For around a hundred dollars you can get either a programmable cycle timer or programmable multi-setting timer. These are normally panel mounted units. My idea was to install a photocell - to shutdown the system at night - then use the cycle timer to set the feed evolution. It could get a bit complicated.
By the time everything was figured it was just about as expensive (and I would get higher capacity equipment) to install a small 12VDC to 120VAC inverter an regular digital timer and a good Pro or Little Giant submersible
pump. Also, a deep-cycle, higher capacity RV or boat battery will probably give better service.
Sorry guys, I don't mean to burst any bubbles (like mine was!) but there ain't any way I can figure to get off cheap on this one.
Ron
K.hygro@gte.net