Originally Posted by copacabana
My two 75w panels top up the batteries during the day (12.8v) and I might see a voltage before sunrise of 12.6 or 12.5 volts. Not very sophisticated, but it works.
I think that is pretty sophisticated! Its basically all I need. Coupled, of course, with an on going daily look at the voltages.
Mine is lower than 12.5 at sunrise... Mine is about 12.3, when the fridge cycles on at sunrise it will be 12.15 at its lowest (about 12.24 unloaded)... thats the magical 50%.
If I was getting 12.5 at sunrise I could drop the fridge a degree down... or start my big fridge up for a 10 minutes 4 times per day as a vegetable crisper... Or charge my iPad, phone and shaver...
So instead of some of the metered ways of determaining consumption I just feel and experience.
Today is sunny where tomorrow is cloudy so I better charge my 'extras' today.