After a full-discharge the battery used for testing has been recharged with the simple circuit mentioned in the post Powering the camera probe for few hours to test if the charging circuit, experimental and very simple, may have problems .
7,5 Vcc / 1500 mA LiIon rechargeable battery
Full charge done (about 3 hours) with the LM350 based battery charger
Power regulator based on LM7805
Raspberry PI B+ with camera running continuously with the frame capture program.
Frames written on a NFS remote mount to have the WiFi connection always working
PiFace Display2 showing a continuously updated message (the system status test) and backlight enabled
The entire system has been packed with cardboard and exposed to almost hot sunlight
The duration time has been calculated from the power-on until one of the components has not presented problems due to the low power.
The entire system worked continuously for 63 minutes then camera continued to stream data but the LCD display backlight gone off and the Raspberry PI power led (the red one) disappeared.
The PI temperature shown on the display never raised more than 43 C