Has anyone measure battery draws when direct driving a P7 using AW single IMR18650? All of my ultrafires can only managed 2A at best. Is this the answer for all of those single 18650 cell P7 flashlights at DX?
keep in mind that when you are testing current for an LED setup, minor changes in circuit resistance can have substantial effects on the lowing current to the LED. Adding a DMM to the circuit could be altering the results....
Having said that, running a P7 DD on a LiMn cell is going to be hit and miss, and will require that you test to see what kind of current it runs at on the cell.. You'll be at the mercy of the Vf of the P7 that is in there.
what he said ^ , plus the device itself might have a lot or little resistance from the switch and wiring in it too.
so when the question comes up, the differance can be all the differance in the world, even from non-copper wire to copper wire.
the resistance of the actual battery used, all that stuff.
even how well the item can be cooled in the device.
chances are good that you can get away with it, or at least with a 1-.5ohm of added resistance, but its really going to depend a lot on how its all connected up.
just wiring it up with cheap wire can put enough resistance in sometimes.