Apparently Motorola fibbed a little on the battery. The iFixit teardown reveals a 300mAh battery but when you do the math with the other stuff in the watch it works out to 320mAh. So long story short....marketing.
Class action law suit in 3...2..
Eh, I wouldn't pick up the pitchforks just yet.
Somebody did something crazy and actually contacted Motorola about the apparent discrepancy and received the following response:
The typical battery capacity for Moto 360 is 320mAh and the minimum is 300mAh. In the mobile industry, sometimes both the minimum and typical capacity is listed on the battery, with the typical capacity quoted as the official battery size. Both figures are included on the batteries of our Moto X, Moto E and Moto G devices. In the case of smaller devices, we aren’t always able to list both figures. For Moto 360, we only had room for one figure and choose to list the minimal capacity of the battery. We see how this can be confusing and we will look into ways to add the typical capacity as well in the future.
Sounds legit to me - but I suppose that could just be PR spin. :dontknow: