led rechargeable 12v flashlight

My experience has been that "most" diodes commonly used for DIY stuff are "power" or "rectifier" diodes, generally made of silicon (SI).  I don't recall every having a silicon one of these that was not 0.7 fV, but then I don't consider myself an expert on the matter.  Due to the "semi-conductiveness" or diodes, saying that a diode has is "0.7fV" may be a nominal rating, a bit like saying that a car battery is "12 volts". :)

From Wikipedia, complete with a simple and enlightening voltage/current graph, comes:

The current–voltage curve is exponential. In a normal silicon diode at rated currents, the arbitrary “cut-in” voltage is defined as 0.6 to 0.7 volts. The value is different for other diode types — Schottky diodes can be rated as low as 0.2 V and red or blue light-emitting diodes (LEDs) can have values of 1.4 V and 4.0 V respectively.

At higher currents the forward voltage drop of the diode increases. A drop of 1 V to 1.5 V is typical at full rated current for power diodes.

http://en.wikipedia.org/wiki/Diode#Current.E2.80.93voltage_characteristic

Damned Kiwis! Always smarter than us mainlanders. (But our Mainland dairy products are nicer!) (LOL!) And imagine that, someone that researches! No Saw, I'm not having a go. Well - not at you!    My compliments on doing what I just joked about elsewhere - that people do NOT search etc. Also in part that there is no "fixed" parameter... hence exponential and other behaviours. EG - I recently saw some refer to "shonky figures" because gains etc were quoted at a certain frequency (1kHz) and they varied elsewhere. It's as if the variables are not understood. (To me it's like saying that "statistics lie". But stats are merely data, so data lies? Isn't it usually their interpretation - whether deliberately misrepresented, or by the non-enlightened?) FYI the Schottky's - I expected the lower voltage units, but they weren't. So why pay heaps more for the same voltage drop when speed is NOT an issue? I think it was merely a "Schottky is better" attitude. But is this thread being hijacked... I lost track...