BruceinBangkok wrote in
:

I was asking about the preferred type of regulator, i.e., shunt, open-
close circuit, short circuit.

If you look at the cells on a heavily loaded panel, notice how brown they
get overheating in the noonday sun so quickly? That should answer your
above question. ANYTHING you can do, like DISCONNECT (read that series
open circuit regulators) an unneeded solar panel in the hot hot sun to GET
THE CELL TEMPERATURE DOWN is always a GOOD thing. The way to get the heat
down is to LOWER, not raise, the cell current. That part of the cells that
don't have any current going through them never seems to change from that
blue silicon color to that brown, scorched-earth look. It's the CURRENT
that fries them. Shunt regulators simply drive up the cell current, which
drives up the cell HEATING until the cell fails....making the cell salesmen
simply smile. Shunt regulators are for suckers.....

My own boat has three panels charging a medium size bank and never
gets above 13.5 V. On the other hand it will only run a DC fridge if
the sun shines all day, every day.
Cheers,


If you can still get a sun tan on a 40' boat who's charging is solar panels
running a fridge with no wind charger....the fridge will easily keep the
cells from overcharging the battery. It's really hard to develop enough
power to fry a LOADED battery with solar cells. BUT...NEVER LEAVE THE BOAT
BATTERIES CONNECTED TO SOLAR PANELS WITHOUT A LOAD!....that'll fry it over
a week.

All solar chargers on boats seem to suck....about like those boat fans
buzzing away over your bunk....cheap crap. But, I'd never use a shunt
controller as it fries the cells in a hot sun at low latitudes. They all
turn BROWN where the current flows!

I've never seen a solar cell fried in the sun unloaded......even in the
Iranian desert mountains.