Originally Posted by
bobn
If you would please Google " Led Circuit Wikipedia " and scroll down to " Polarity " it may better explain my statement.
Sorry that I can't post the link, I just don't have the computer savvy nor do I have the electrical knowledge to explain it better.
The reverse breakdown voltages are normally very large, such as 100-200V, well in excess of what a battery or generator can provide. Those voltages can be purposely lowered, as in Zener diodes or in photodiodes, but that is normally not the case in LEDs. They can be safely used in reverse polarization - they will just not light up.