CREE XR-E bulbs and voltage

[mdt1007]

how voltage tolerant are these CREE LED bulbs? The item description says 4.5v to 9v but did not elaborate. are there any electronic voltage controlling mechanisms built into the CREE system?

http://tinyurl.com/38ow9m

I'm thinking about using Rechargeable Li-ion 123s (http://tinyurl.com/2v9rb2) with a Surefire 6P fitted with the CREE. I realize rechargeable 3Vs are not exactly 3Vs fresh off the charger (but how high voltage are they?) and blew my first P60.

 

[xiorcal]

Crees range from 2.8V to 3.7V within spec. They go up to 4.2V or something at 2A, but that is severe overdriving, and likely to burn them out sooner rather than later.
To get 200lm out of one LED, the drive will probably fall within spec.
"The item description says 4.5v to 9v"
Cree LEDs don't have voltage contol mechanisms built into them. They are simply LEDs. That module you are looking at will have a voltage control mechanism built into it, because if it didn't, 4.5V-9V would instantly fry the Cree. The voltage controller will be either a resistor -wasteful- or a "driver", which may be more efficient.
Rechargeable Li-ion 123s (Commonly refered to as LiR CR123, or just RCR123) will be at a peak voltage of just under 4.2V when they have just been charged, but their voltage will fall to as low as 2.7V during their run. You will need to use two RCR123s, to run the module, but it should run fine on them. (8.4Vmax to 5.4V LiR low-voltage cutoff. Right in the middle of the stated range.)

If the module blew, you would have a good case for your money back, seeing as they don't state what kind of batteries to use it with, just the voltage it should accept.

-Xiorcal

 

[barkingmad]

how voltage tolerant are these CREE LED bulbs? The item description says 4.5v to 9v but did not elaborate. are there any electronic voltage controlling mechanisms built into the CREE system?

http://tinyurl.com/38ow9m

I'm thinking about using Rechargeable Li-ion 123s (http://tinyurl.com/2v9rb2) with a Surefire 6P fitted with the CREE. I realize rechargeable 3Vs are not exactly 3Vs fresh off the charger (but how high voltage are they?) and blew my first P60.

'Fresh off the charger' does not really apply with lithium rechargeable cells - they generally have very low self-discharge so come off the charger and stay at that voltage. Just tested two 3.6v RCR123's - would have come off the charger around 4.18-4.20v and both are about 4.17 now (after about a week).