Canon EF-M - Manual (Page 12)

4) Set the aperture dial to
5) Look through the viewfinder and press
the shutter button halfway. If the view­
finder's exposure display lights up, the
battery is OK.
* If nothing at all appears in the view­
finder display, the battery may be in­
serted backwards. Reinsert the
battery with the terminals facing
inward.
* If the " 0 ” indicator (see page 9)
blinks in the viewfinder, replace the
battery with a new one.
When not using the camera, set the
aperture dial to “ B”. This prevents
pictures from being taken accidental­
ly and unnecessary battery drain if the
shutter button is unintentionally
pressed halfway.