Solarforce XM-L U2 Drop-Ins?

[Kestrel]

indeed...you see I have (and a fellow greek member also has) measured the efficiency of similar 3.6-12V drivers of the cheap chinese XML modules.
these are actually overdrived "Keenan" type drivers with the sens resistor set at 100mOhm (instead of say, 270).
Efficiency was 50% unless a single Li-Ion was used where the LED was run DD.

Great info, very interesting to read this, thanks. For all the folks here on CPF asking about runtimes, almost nobody knows to ask if they're only getting ~half the runtime that a better driver design might deliver.


Edit: The thing is, there seem to be only a few high-current, high-voltage drivers out there; to know that the efficiencies of these vary widely would be of assistance when folks are trying to get the additional runtime that multiple LiIon cells might be able to offer in a P60-format. If the package efficiency drops considerably, there would seem to be little advantage to adding that second cell. Very interesting.

 

[kosPap]

The Derrelight 2.5A 2MT modeule river seems good....

I had one driver left over from a mod (till i shorted the LED wires and fried the driver)
I measured a 1.52 A draw with 2x18650. Output was 800 lumens.
I cannot make calcualtions ATM. Anyone else?
BTW I feel it is the only way for a P60 moduel compatible driver. And it also looks better than the chinese (has a huge ferrite coil) and it is VERy clever how it converts from single to multi mode.

 

[texas cop]

Update to this dropin. So far I've put 10 lights together with this dropin. On a charged 18650 I'm getting 2.06 - 1.95 amps with 1 doa.