Got my backup in the mail today and took some lousy pics (it’s nighttime so light source sucks)
When I received this Uniquefire Uf-F15 today I knew that the big ground spring would be a major resistance point and it was, but not as bad as the original light.
I removed the battery tube and cleaned the shelf area and the spring itself and measured amp draw. 2.02 amps, better than the original, but not what we are looking for.
Next step was to use braid on the ground spring, this brought it up to 2.30, next driver spring braid, up to 2.43, now time to remove driver.
This one has a small retaining ring, press fit and the driver was press fit as well.
Anyway after pulling the driver I soldered a small piece of tinned wire across the open spot on the board just below the sense resistors.
Here is the driver in question;
The spot where I jumped is at the top left of the driver.
Everything else I left alone.
Now she pulls 3.5+ amps on a decent battery. I let it run for 20 minutes on high and it got good and warm, but never Hot. This light has good thermal sinking for a stock aluminum pill.
The pill sits kind of loose in the threads so I l would like to get some thermal glue perhaps, something thicker than the thermal paste that I have.
I have no idea if this light has low voltage protection, either before or after modification. If you are modding this light for this much amp draw, you are responsible to check cell voltage as you progress using the light.
Anyway if you want something different than the regular C8 flashlight, these are different and pretty decent and best of all, the mods cost next to nothing, now THAT is what I call Budget Light Forum modification 
This is where I ordered the backup light from, Very fast shipping and you get a charger and cheap azz battery.
http://www.ebay.com/itm/181270907643?ssPageName=STRK:MEWNX:IT&\_trksid=p3984.m1497.l2649
Charger terminates right at 4.20-4.21 consistently and does not get hot or get the cell hot, so what’s not to love.
Later,
Keith