Casio DT-X11 Series Hardware Manual page 33

Memory backup battery
Battery type
Rated voltage
Battery low warning
Low main battery voltage
Forcible OFF
Low sub-battery voltage
Button-shape Lithium
rechargeable battery
(CR-2032)
3.0 V
VDET1: 3.4 V
VDET2: 3.0 V
VDETS: 2.3 V
33
Warning display, but still operable.
Forcible OFF.
Data cannot be retained.