This is unfortunately normal, especially if you have a thick wall between the chime and camera. The antenna on the chime and camera is extremely weak, on the chime the antenna is directly behind the speaker therefore also impacting signal strengh. Unless you have them right next to each other with no obstacles inbetween the battery will litteraly last more than a month (I have tested this but totally useless of course) As soon as you introduce an obstacle, even as thin as a plaster board between the chime and camera the signal between the two start to degrade exponentially, the camera will then boost its signal output therefore consuming a LOT more battery.
IT DOES NOT MATTER HOW YOU CHARGE THE CAMERA, you can charge it via the chime or any USB charger it MAKES NO DIFFERENCE. I have opened the chime and camera to look at the chipset and vendor to see if there is a way to get more information but there is nothing on the internet. I was thinking about soldering in a larger antenna but its more practical to just buy a better system.
