"Mark" wrote in message
ups.com...

Bert van den Berg wrote:

Is it true, however, that you always need a reverse blocking diode on
all solar panels that don't have one in-built?

Maybe on some panel types, but I'm with you, 33milliamps leakage from a
40 watt pair of CIS panels into a 500ah bank.

Don't follow. (also haven't seen previous part of this) ISTR the purpose of
the blocking diode is to prevent the battery from charging the solar panel
at night.

Regards,
Barry












Installing blocking
diodes would be a loser because of forward voltage drop when the panels
are high noon producing with near fully charged batteries. People who
say always install blocking diodes paint with too broad a brush.

Blocking diodes are a good idea when constructing higher voltage
series-parallel strings, to prevent damage to shadowed panels.