hi volvo farmer,
300 plus days of sun sounds like a nice place to live with pv power. and a perfect match for a controller that tracks with light sensors.
as for this timer, if someone told me this prior to august.4th i would have said no way...but i can absolutely confirm that this timer runs stand alone, full function, without any outside power source of any kind be it grid or otherwise.
can i explain it? no. in fact this has had me totally baffled for over six weeks! this CR2 battery is 3volts and 800ma thats a grand total of 2.6whs. i have one of these timers here on the coffee table that i have cycled upwards of 10,000 times so far! if i thought i was sure i could explain it i would have taken a clam knife to it by now..still may! heres a bit of speculation, they may be capturing the coil collapse energy somehow?
on of the first things we did was to power one of these timers up with a series pair of D cells with no trouble. also, i bet even i might be able to work up a stable 3volt supply from our battery bank if it proved necessary. this timer is a hidden gem to us involved in these battery based systems..on a sad note the company just destroyed about 400,000 of these timers in a recall because the old model had the ac (when used in ac applications) exposed..so when people were changing the batteries..bad things would happen.
so many things are still a mystery to me.
kind regards, dave