I am in the power outage capital. After having watched all these super flashlight commercials, I decided to gather all my MAGLITES and change them to Terralux LEDs. That seems to have increased the lumen output and run time on standard batteries.
While looking at the various ways to "hack" your flashlight, I learned about pulse width modulated LED drivers designed to operate the LED at peak power making it brighter (around 10 to 20 watts). The standard LED operates around 120 to 200 lumens, where the pwm modulated driver can push some LEDS to operate around 9000 lumens. You can build and progan your own led drivers, but the commercial ones are small enough to stuff in a slightly modified MAGLITE.
If that wasn't bad enough, by modifying a standard "D" 5 cell flashlight to use AA series battery holders, you can increase voltage to around 22 volts, which allows use of bigger LED arrays up to about 200 watts. Heating issues at this level. I have been reading on how to adapt an old AMD processor and cooling fan to the LED array.
My call sign is KK4AMI and I think I am becoming a Flashlight Hacker Whacker.