Solar Panels, Blocking Diodes??

Thanks John, I had read on some sites that suggest using a diode to prevent problems with feedback from one panel to the other when in partial shade.
Chris

Thanks for the reply, looks like I wont be putting any diodes in.
Chris

Hi Steve
My panels do have diodes in the junction boxes but as I understand it they are by-pass diodes and not blocking diodes.

They are diodes to stop current flow at night from the battery so maybe they are what you are calling blocking diodes ...

Cheers

Steve

May be wrong, but as I understand it, blocking diodes and bypass diodes are not the same thing. Blocking diodes prevent current flow back to the panels at night, while bypass diodes are connected across the terminals of each panel to shunt the current around a shaded, weak, or damaged panel when panels are connected in series for higher voltage systems than 12v.

Ya learn sumthin new everyday here !!

Blocking Diodes.
While a solar panel "puts out" in sunlight, it "takes back" after dark, although the reverse current flow is much less. At the time of installation, a blocking diode is frequently added to the wiring to the battery. Such diodes are installed in addition to the bypass diodes found in some panel junction boxes and should not be confused with them.
A blocking diode has the effect of allowing the charging current to pass to the battery, but blocks any reverse current flow. However, such diodes cause a voltage drop of around 0.6 volts, which means that for a panel to remain an effective battery charging device, its output must now be rated at 14.6 to 15.0 volts. A 30-cell panel with a blocking diode, partictularly in a hot climate, will be almost compIetely ineffective; even a 33-cell panel will start to suffer a decline in its output as a battery comes up to charge.

Cheers

Steve