I've got a B stock Lumitrix BFL (3x XM-L @ 3.3v/3a in smooth reflectors) and one LED has shifted to a colder color and lost about 1/3-1/2 it's output. Just a bad one I guess, anyway I know I can drop in XM-L2's at the same voltage and current without issue but I want more throw and less flood and if possible more safe output, would XP-L HI emitters be safe to run at 3.3v and 3a?
Light below, not my light but close enough.
Yes, the XPL HI should have similar forward voltage (maybe a bit different, but I should think the driver should be able to handle it) and can handle that current fine and should increase the throw of the light. You mentioned wanting more output; if you can modify the current the XPL HIs can take a lot of current safely as long as the thermal path is good (DTP MCPCB), up to ~5.5A at least.
Looks interesting; what is the light used for? Are there batteries inside?
No batteries inside, honestly I haven’t found a use for it yet I bought it because once they were gone they were gone and I just wanted one. Impulse buy I guess you could say….
The drivers are potted inside so I don’t think I’m going to try to alter that, if I could find a place to mount it I’d use it as additional high beam light but that’s proving difficult.
I plan on using a sold aluminum rod to mount it which will act as additional thermal mass and heatsink area, it’s meant to be mounted on round pipe for some reason, odd choice but whatever.
The XP-L HI is spec’d by Cree for 2.95V at 3A, I know it’s amps that make the light so I wasn’t sure the effect of additional voltage would be. Would the XP-L HI at 3.3V and 3A put out similar amount of heat to the XM-L or would it be more or less heat? If it’s more heat then I’m not sure it’ll be safe for long periods of use, as it’s designed now it can run forever with just passive cooling sitting still.
Most likely the drivers are designed to be constant current, so they will apply the voltage required to send 3A to each XPL HI. The heat will be similar to what you have now. Maybe a bit less because the new XPL HIs will be more efficient than your XMLs.
I’ll try to find out exactly what drivers were used if the fellow will disclose it.
Welcome to BLF!
Can’t help you but some pics of the inside might help others help you 
Well it’s fully potted so it’s pretty hard to see the innards.
So here’s what I got
To me, based on my knowledge of how power supplies work, the statement that it will output exactly 9.95V @3A is not clear. It will either output 3A to the XPL HIs and the voltage would be whatever the forward voltage at 3A is, or it will apply 9.95V and the current will be more or less than 3A, depending on what the actual forward voltage of the XPL is.
Also, cree quotes the forward voltage of the XPL at 2.95V at 1.05A, not 3A. The forward voltage of the XPL at 3A will be more like 3.4-3.5V
Got it, so there’s a good chance XP-L HI will work fine, I’ll order some up once I get the lens off to check the exact star size needed and thickness.
Yes, I think it will probably work fine.
I was curious about this light so I looked and found this:
Looks like a good solution for vehicle applications.
Never seen one of those, what is it used for, who sells them?