HP HP-65 - Battery Pack Replacement

All decimal points in the display light when 2 to 5 minutes of
operation time remain in the battery pack. Even when all the
decimal points are lit, the true decimal position is known be-
cause an entire digit position is allocated to it.
Battery Pack Replacement
To replace your battery pack use the following procedure:
1. Turn the power switch to OFF and disconnect the battery
charger.
2. Slide the two battery-door latches toward the bottom of the
calculator.
3. Let the battery door and
battery pack fall into
the palm of your hand.
. See if the battery
connector springs have
been inadvertently flattened
inward. If so, bend them out
and try the battery again.