HP 10BII Owner's Manual page 120

4. Remove both batteries.
There is a danger of explosion if batteries are
ü incorrectly replaced.
Warnin
9 Replace only with the same type of battery or with
equivalent batteries (as recommended by the
manufacturer). Dispose of used batteries according to
the manufacturer's instructions.
Do not mutilate, puncture, or dispose of batteries in
fire. The batteries can burst or explode, releasing
hazardous chemicals.
Do not use new and old batteries together, and do not
mix batteries of different types.
5. Insert the new batteries, making sure that the positive sign
(+) on each battery is facing outward.
6. Replace the battery-compartment lid.
7. Press (G9).
Tf the calculator does not turn on, follow the procedures in the next
section.
120 A: Assistance, Batteries, and Service