How To Install A Blocking Diode For Solar Panel

Blocking diode in a solar panel is used to prevent the batteries from draining or discharging back through the pv cells inside the solar panel as they acts as load in night or in case of fully covered sky by clouds etc.

How to install a blocking diode for solar panel. The diodes are to prevent the battery discharging into the panel at night. Learn how and why blocking diodes and bypass diodes are used. However in the dark when no voltage is being produced by the panels the voltage of the battery would cause a current to flow in the opposite direction through the panels discharging the battery if it was not for the blocking diode in the circuit. And for low voltage setups like 12 volts an old wind sun faq says that a blocking diode really does not save much power anyway.

In simplest terms a diode can be understood as a two terminal electronic device which allows electrical current to pass in one direction. Blocking diodes installation instructions sm 335 issue c 03 11 05 marlec engineering co ltd blocking diodes a blocking diode is required in each series string of solar modules between the modules and regulator battery to prevent current flowing back through the modules when the modules are shaded or during darkness. A blocking diode and bypass diode are commonly used in solar energy systems and solar panels. Charge controllers block any current leaks back to the panel.

Again current flows from high to low voltage so during a sunny day the voltage of a solar panel will be higher than the voltage of a deep cycle battery and the. For larger grid tied. The blocking diodes are really only needed on panels that connect directly to a battery bank and the bank is 24 volts or larger. In short as diode only passes current in one direction so the current from solar panels flows forward biased to the battery and blocks from the battery to the solar panel.

If you have two 175 watt panels each at 42 volts you will need two 8 amp 45 volt diodes. Most folk connect the panels to an inverter which sometimes have their own blocking diode some simple checks with a current meter will indicate if you need one in your setup or not. For solar panels we recommend you put one blocking diode on each solar panel inside an abs project box the diode needs to have a voltage and amperage rating above that of the panel. Diode and unidirectional flow of current.