I just got mine, but it seems that the spring in the tail cap is either 1. broke, 2. stuck, 3. missing. You know that little metal cap that goes over the spring in the end cap? Well, mine is pressed way in and won't budge a bit. I'd take the tail cap apart, but I can't budge the little whatchamacallit that's suppose to spin out. Maybe it's because I haven't thought of a good tool to use to unscrew it (needle nose pliers are too fat at the tip).
There is no spring in the tailcap..it's a copper or brass contact directly on the board..there is a spring at the driver end though for shock absorbtion..
im actually thinking about adding a small spring on mine as i get flickering on mine. snap ring pliers work best. a small awl or 2 has worked for me too.
Got my DD UF-2100 3 mode with a battery for $14.97 via a Chibi heads up deal. The battery is an Ultrafire BRC 3000ma 18650 and flashlight is branded Uniquefire and Cree XM-L T6. My test with my Turnigy 8150 the BRC 18650 showed a hair over 1500ma discharge 3.0V @ 1A. Tail cap amp draw showed .18A on low and 3.3A+ on HIGH! This is with a Tenergy 18650. Gets warm quick on high. Thanks again Chibi aka "DD DEAL MASTER"
Really? Okay... I guess I was just use to my C8s, etc. that have a spring there.
I use that from DX is really good just shaping the sharp ends
http://www.dealextreme.com/p/weitus-stainless-steel-precision-straight-tweezers-19872
I have that
buy weitus tools other from china are done of plasticine
Here some photos unscrew all clean with alcohol and reassemble all close
http://forum.fonarevka.ru/showthread.php?t=5637
if your battery loose on the body use round magnets like that
usefull also to charge smaller batteries in bigger charger(but take a look at the A of the charge 1000mA for a 10440 battery is not a good idea)