With full exposure to direct sunlight, the built-in solar panel can collect and store 450 to 900 mAh per day. eufycam S3 Pro uses 100 to 200 mAh over a day and night of average use, with 1 hour optimal sunlight, the camera can keep working for an entire day. However, this depends on the strength of the sunlight. Install your camera in a position that exposes it to as much sun as possible. The eufyCam S3 Pro can be charged using an external solar panel when you need to install the camera in areas with insufficient sunlight (e.g., under the eaves). The external panel works in conjunction with the built-in solar panel so you can get versatile mounting options and more reliable backup power for continuous security.