I had experienced this and also check as you did on my friend z10, note 1 and 2 and it resulted same as u were, I donno what method the manufacturer rate their battery caps, most of the non oem battery can only be charged up to 85-90 percent but on the phone it will shows as full cause most of the phone can't read the aftermarket batt properly..not to offend sellers but for awareness, u won't get actual power as stated MAH..BTW I'm using this batt(3150MAH) too on my s4 sometimes as spare and it perform same hours on the same usage as OEM batt..