And you have hit the big problem with mirrorless.... battery life. They increase the power consumption and make the battery smaller.... and for some inexplicable reason, battery life sucks! If they kept to LP-E6 they would last longer... or with a mirrorless in a "normal" sized camera there would be room for a larger battery.
70D, LP-E6 battery, 1000 pictures per charge
EOS-M, LP-12 battery, 230 pictures per charge
LP-E6 is 7.2V and 1800mAh
LP-E12 is 7.2V and 875mAh
If you look at in term of pictures per Ah, the 70D is 555 per Ah and the EOS-M is 265 per Ah.... so assuming the same battery capacity you are still at only half the life on the EOS-M as the 70D
Of course, according to the official Canon numbers, the 70D only gets about 230 shots in live view, or 152 shots per Ah. I can't imagine why its battery life in live view mode is only half that of the EOS-M, rather than being about the same, but there you go. Either way, the point remains that active displays draw a lot of power.
FWIW, this past week I shot over 500 frames (and a 90 s movie) on a single fully-charged LP-E12 in my EOS M (and I could have shot more, but I swapped in a fresh battery as soon as the red-flashing indicator came on). I shot about the same number of images on my 1D X, and used less than 35% of the LP-E4N's capacity (no need for the spare battery this trip).
The more useful statistic would be minutes with the screen lit. Taking the photo is lost in the noise by comparison. If you shoot photos relatively quickly, you'll get a lot of shots. If you take five minutes between shots, you won't get very many at all.
That's rather the point, isn't it? Previsualize the shot, turn on the camera, compose, focus and shoot. If there are people in the shot, fire off a ~3 frame burst. Don't spend a lot of time chimping. Good technique can make more effective use of battery life. The >500 shots on one battery were spread over three days of use.