Answer: Place it where it can get a lot of sun and regularly inspect and clean the solar panel.
Cameras with integrated solar panels will charge quickly when positioned where it gets full sun. Consider this when fitting your camera and try to minimize how much shade it gets and adjust the direction it faces to ensure it can receive the most sunlight while covering your area of interest. It is also a good idea to clean the solar panel, freeing it from any object or dirt that might block the sun; NO CHEMICALS REQUIRED. Anything that blocks the sun from reaching the solar panel can impact the charging efficiency, keep this in mind when installing the cameras as well.
TIP: Read more here on how to optimally position your MaxRanger4K™ camera or solar panel.