How effective are these drivers at maintaining output level, or do we loose some output as the cell empties?
If i have a 500 lumen light, that is current regulated from 2.7 to 4.5v, do i get 500 lumens from an 18650 until the voltage drops to 2.7 volts?
Cheers
Matt
It depends on the driver, 7135 based drivers generally stay in regulation until around 2.8-3 volts.
Thanks for the reply 
Would the output also be dependent on the quality of the cell, and it’s ability to sustain the right amount of current?
Cheers
Matt
Yes, some cells can sustain high current all the way through their discharge curve but other can not. I would recommend just getting some decent brand name cells. (No xxxxfire cells)
I’m using a Panasonic cgr18650ch with a 4.5A xm-l on copper P60. I just used my explanation in the first post to keep it general about current regulated drivers.
I haven’t ran a cell down in the light completely yet, but i’m trying to figure out if i am(or should expect) full brightness for the entire cell. I suppose i will get quite a large drop in lumens as heat builds up anyway.
Cheers
Matt
Either way it will decrease in brightness as time passes.
Ok thanks.