I have gotten about 1350 shots with it on my 7d, well above the 1000 Canon says it gets. I even used IS and AF, and the LCD screen maybe half that time, but I tend to keep the "auto turn off time" short. I get 1500+ with my opteka 2400 mAh.
Another question: I've tried desperately to find this info, and can't find it anywhere!! How long are you guys able to leave the shutter open for a long exposure shot with one LP-E6?? (no battery grip) So far, at 50-60 degrees outside, I can get about 35-40 minutes, sometimes more, but it seems to vary. I would really like to know what other people get because if you get 40 minutes, but have long exp. noise reduction on, and leave it open for 25 minutes, it won't make it through all 25 minutes of the noise red. part, wasting all that time. Thanks guys, appreciate the help