Sierra Monitor Corporation T10008 - Manual (Page 12)

OXYGEN DEFICIENCY MONITOR PAGE 10
8. Battery Replacement
8.1 When the “BAT” indicator is displayed approximately 8 hours of
battery life remain.
8.2 Slide off the battery cover located on the lower rear of the unit.
Remove the battery and disconnect.
8.3 Connect a new battery and carefully install it in the compartment
taking care to stow the wires in a way in which they will not be
crimped or cut by the cover. Place the cover back onto housing
and secure with the four screws.