Can the KL4 Run on 9 Volts

I have a 2 X 17650 Body on the way to me and I'd like to know if this is possible...I also have an L2 Body that will be bored out to accept 3 X 123's and be able to use the 2-stage tailcap. I just don't want to kill my KL4.

Has anyone done this without problems?

My first gut feeling is that it can't.
I will look into it though.

EDIT, circuit is boost only - don't do it!

Surefire has never recommended using the Lux V KL4 with three CR123 batteries. They have recommended using the KL5 Lux V, also utilizing a constant current boost circuit, with three CR123's, something that has always puzzled many CPF'ers, particularly those that have good knowledge about constant current boost circuits. Many have surmised that a Lux V LED with a high vf (forward voltage) would be able to tolerate being over driven at 9 volts, and the voltage sag of the CR123's would soon drop the voltage down below the vf of the LED, and then the KL5 would run in regulation. Also there is more metal in the KL5 head to draw off heat from an overdriven KL5 boost circuit. This premise for the the KL5 would not work with the KL4 because there is not anywhere near the mass of metal that the KL5 has, and we know that the KL4 gets hot fast at standard specs with two CR123's, or one Li-Ion.

Bill

KL4 is boost only. I forget the exact part that was used (it's made by Linear Tech) so once you overcome the diode drop and DC resistance of the diode, you will be in direct drive mode. I'd say budget about half a volt for the diode and IR drop. Too much for the Lux V.

If you have an ammeter, you can put it inline with two 17670's (do this quickly) and the current you read will be the current going through the LED. The ammeter does have series resistance so use the highest (typically 10A) range to minimize the error.

I just bought a KL4 an hour ago. No go with 9 volts, although the KL1 can handle 9v.