[stevehull]

Daox,

What was the back flow current (in the dark) as a resistive equivalent. In other words, was the backflow significant as in the PV panel "looked like" a low resistance shunt? Am trying to recall the Norton or Thevinen equivalent . . . .

In other words, how low was the equivalent resistance (50 ohms or less?).

I am discussing this with a friend that has a Apollo driveway gate opener (deep cell marine battery charged with a 10W PV panel). He complains that he has to replace the battery every couple of years. It fails in mid January every time. He is blaming the control board and to replace it Apollo wants $375.

The 10W panel is likely to small to keep up with his gate opening frequency in mid winter when we have little sun and LOTS of dark night. Finally the battery electrolyte is almost like water - and on a frigid cold night (down to 5 F or so) it freezes, shatters the partitions between cells and is useless as a 12 V battery.

Suggested a 1N004 diode ($0.20, e-Bay) in series with the positive lead to battery . . . but he doesn't believe that the battery will back feed at night.

$0.20 vs $375 . ..

Steve







Steve