Sony AIBO Explorer Guide De L'utilisateur page 48

Tail sensors (available with ERS-220 only)
The tail sensors of AIBO have functions useful for you to get along with AIBO.
Tail sensor (right)
This sensor represents the current emotion of AIBO by using other lights, motions
and sound. See page 55 for what each light indicates.
Tail sensor (Center)
When you press this tail sensor (center), the retractable head light lights up (see
page 56).
When 10 seconds pass or you press the tail sensor (center) again, the retractable
head light turns off, and is retracted.
Tail sensor (left)
This sensor uses the back multi-indicators to show the remaining power level of the
battery pack.
Full
48
Tail sensor (right)
Tail sensor (center)
Tail sensor (left)
Weak
Slowly flashes.