Well, I finally got my V2 fixed after dropping it from kitchen counter height. It landed on the battery end and caused the KFL clone to push the center positive pin, in the 510 connection into the inside of the cap. With a large pair of pliers and a thick belt (to keep from marking up the cap), I was able to gently pry the top cap off, replace the center positive pin, solder the wire, put it all back together and make it work again. It lasted for about a week and then it took a hard, hard fall off the top of a 5' water heater. With a KF 3.1 clone attached, it landed on the drip tip and came apart. The fall made the top cap come off, broke both wire inside the top cap, the drip tip went flying but the KF clone stayed together. I, once again, re-soldered the wires, super glued the board and put it all back together...again. It WORKS! I'm impressed, this thing is amazing. It's been dropped and repaired more times than I can count and it continues to work. 
This V2 was my first real mod after starting out with a Volcano Inferno last October. The fire button is getting a bit on the soft side and I'll eventually replace that button, but I've got to say, this Sigelei is an awesome, inexpensive and well built mod that keeps taking abuse and keeps working and working. It's the best $60 I've spent so far for a mod. Go Sigelei