Rotating between various Apple watches I own, if it’s turned off and put away for a couple of weeks, I would see the battery life at 40 to 45% when I start storing it. I usually do it at about 60 to 65%.
There is no application that is using up a lot of battery. I have already tested disabling all the apps and they still use up the battery, even when turned off they do not last more than 12 hours on battery. I think it is a problem with the motherboard.