Just an eGo 3.7v battery.
Errol
Ah, well when I look at it from that perspective it does look a little different - I also killed 2 ego (TW Tornado branded) actual batteries in couple weeks on little atties and cartos, but not the circuit part, just the actual cells - mine just didn't like being recharged much and failed quite badly, hence I ripped open the 2nd failed one, ditched the U/S cell and used the tube and c'board as a ~3.3v PT. - The electronics have held up OK though, so I just put it down to crappy cells inside?..
DV