Cree Q5 direct drive?

Hi,

I want to built in a Cree Q5 in a AA m@g.
what is the best way to go on?

2xAA cell
1x14500 cell?

dan i direct drive it on the 14500? or 2xAA?
Or do i need a resistor/driver?

I have a Romisen RC-W4 which is completely direct driving a CREE P4 and nothing happened to it after months of use with a 17500 Li-Ion battery. The led is pulling 1400mA from the battery when fully charged and gradually dims as the battery gets discharged,

So how sure are you that is will work for a Cree Q5 as well?

I modded this with a Q5 and is powered by a much bigger 18650.
In about one hour, the entire torch gets a mild fever, but it doesn't peak above one amp with fresh charged cell.
Now my father enjoys it, as i bought another and dropped a ssc p4 in for the wider spill and wider spot.
Just check the current with a (as in "one" and not "two") slightly discharged 14500 cell and make shure it does not pop over 1amp or so.
With proper cooling, those Cree leds will take a beat and then some.

p.s. It will not get lit at all with two AA cells. Perhaps it will put out a few candles at most.

yo6ial said:

Just check the current with a (as in "one" and not "two") slightly discharged 14500 cell and make shure it does not pop over 1amp or so.
With proper cooling, those Cree leds will take a beat and then some.

Click to expand...

Thanks for the advice.... i'll try with a 1/2 discharged 14500 first.
I hope it will not

ktafil said:

So how sure are you that is will work for a Cree Q5 as well?

Click to expand...

StefanFs has driven CREE Q5s at 1500 and 1600 mA. With proper heat sink there should not be a problem. As some people write here, your LED will not last 100000 hour but will last enough (2000+ hours).

Sounds promising.
Now just waiting for the stuff to get here :naughty:

Okay, here it is.....

I built the MM with cree Q5 running on a single 3.7V 900mAh Li-Ion

When running it pulls 1.9Amps on 3.5V from a just fully charged battery
This is quite a lot, i'll re-measure the Amp's later when the battery is used for a few minutes (have no multimeter here now)
I hope the LED will not in the meanwhile, but it surely is a lot of light for a MM! :naughty:

I run Cree XR-E's in DD occasionally, and I carefully sort through the emitters I have on hand to find one with the right front voltage that will work with *that light*. The resistance of the switch affects it a lot. I have seen XR-E's pull from well below 1 amp to over 2 amps off an 18650.

If I were you I'd add in a resistor to get the current down.

ktafil said:

Okay, here it is.....

I built the MM with cree Q5 running on a single 3.7V 900mAh Li-Ion

When running it pulls 1.9Amps on 3.5V from a just fully charged battery
This is quite a lot, i'll re-measure the Amp's later when the battery is used for a few minutes (have no multimeter here now)
I hope the LED will not in the meanwhile, but it surely is a lot of light for a MM! :naughty:

Click to expand...

Okay, after the freshness is off the battery i measure:

3.4V / 1.3A --> this is what I have read before.
It will shorten the LED life, but sill still be a lot.
The Apm's are ,measured at the tailcap, so switch resistance will lower the Amp's a bit with the wsitch in place.

The light is sure very bright for a mm

https://www.candlepowerforums.com/posts/2864183#post2864183