Note: I'll try to get all the facts accounted for up front. I have a Leica X-E, which should be identical to the X2, but with a more economical exterior finish. I have 2 batteries - same battery as the other X's. I've been shooting with the current battery for about 4 days, the last 2 days at 1/3 charge according to the battery meter. I took around 150 shots to get down to 1/3 charge, and another 100 after that. I decided today to set the camera to forced flash on, ISO 200, and fire off flash shots in a dimly-lit area. I was in my car outdoors in hot and humid South Carolina for the first 350 flash shots, then had to break for lunch. BTW, the car (which has no air conditioning) was sitting in shade, and the camera was pointed at the dark floor. The pop-up flash unit got barely warm, and the flashes were bright. After lunch I continued in a dimly-lit room at home, for another 228 flash shots, for a total of 578 before the battery meter changed to red. Another 51 flash shots after that and the camera shut down. Summary:  ~250 shots taken over 4 days in daylight, or night on tripod without flash - battery meter at 1/3 charge for the past 2 days.  578 forced-flash shots taken - battery meter now on red (zero charge).  51 more forced-flash shots taken - camera now shuts down. It's interesting that, with the meter on 1/3 charge at the start, I kept expecting it to shut down at any moment. I got to thinking that the camera was drawing "free energy" from somewhere. Or else there were gremlins inside running on a tiny treadmill. So I have no explanation, other than the X-E draws extremely little power (even with flash shots), the battery is fairly heavy-duty, and my batteries are genuine Leicas. 629 flash shots taken, one at a time, after the meter showed 1/3 charge.