Hand Held Products 71 Instruction Manual page 10

¡ Battery Life
Your 64K battery backed-up M/M should retain its
memory for approximately 13 months while your
32K battery backed-up M/M willretain it's memory
for approximately 29 months. These figures are
based upon "worst-case" conditions. That condition
would have the M/M "sitting on the shelf'with the
cover intact and never being installed in the HP-71.
Under normal use i.e. being installed in the HP-71far
more frequently, your battery backed-up M/M will
retain its memory ever longer. Once again, to
maximize the life of the battery, the snap-on
cover must be on the M/M any time the
Module is outside the HP-71.
Note:
"Normal
use" is considered as leaving the M/M inside
the HP-71 approximately 80o/o of the time. Under this
condition your battery life should extend up to 5 years.
It is a simple task to replace the battery in your M/M.
The only material necessary is a 71 M/M
Battery Replacement Assembly which comes complete
with everything you need and can be installed in
minutes.