Cree Flashlight upgrade!
A fast mod to transform your regular flashlight into a pocket sun! I started with a Sipik SK68 AA flashlight with a medeocre Cree XRE-Q3 diode. There are similar "zoomable" AA models from other companies, but this one appears to put out the most current on the factory driver. It's a good baseline for the upgrade.
Unscrew the top to remove the adjustable lens focus. Most flashlights of this type come apart like this.
Remove the retaining ring with needle nose pliers.
The entire "pill" can now be unscrewed and removed from the body of the light.
Now for some basic soldering! Remove the old Q3 emitter, and replace with a higher powered Cree XML-T6 on a 16mm board. (Shop around, better bins are already available.) Be sure to put some thermal paste below for better cooling.
Comparison of Q3 emitter to the XML. The size and angle of the emitter is different, so there will be a trade-off. It will be MUCH brighter, but it will not focus as much for ultra long distance throw.
Upgrade the battery to a rechargeable lithium 14500 battery, the same size as the old AA. It runs 3-4 volts and will get more current out of the factory buck-boost driver circuit.
Now for the results! Camera set in manual, -2 to exposure, CONTROL PHOTO:
Original Q3 on a fresh 1.6v Alkaline battery.
Upgraded XML T6 with 14500 battery (decently charged at 3.8V). You will get about 40 minutes of run time in this tiny package.
Side by side. In person, now everyone complains about how bright it is. Mission accomplished.