@vladimir61 

- the app notification is only for the camera's owner, or for the guests who share device too?

If camera notification is enabled by the owner, the shared account will also receive camera detection notification.

- about connection of usb adapter; the camera will be connected indoor, but if we use a panel solar A200 the battery is charging all the time, affect the battery life?

To place Tapo C425 and solar panel outdoors, waterproof protection is required. There are waterproof seals included with the A200. How to connect Tapo Solar Panel to compatible Tapo devices with proper Waterproof Gasket

Solar charging is not continuous and varies depending on the light intensity. In addition, after the camera battery is fully charged, the next charge will only start when the battery drops at about 90% due to the battery protection mechanism.

- is possible to use the a100 battery on the camera tapo c425, to exchange between two batteries?

Tapo C425's battery is non-removable.

- is possible to know the battery status, for example charge %, or days remaining or other?

Camera battery status will be displayed within the Tapo App.