ProSoft Technology ILX56-MM - Manual (Page 4)

Battery Life Advisory
This module uses a Lithium Vanadium Pentoxide battery to backup the date/time settings of the real-time clock and
the BIOS settings in CMOS. The battery recharges whenever the module is receiving power and should not need to
be replaced for the life of the module. The module must be powered for approximately twenty hours before the
battery becomes fully charged.
If the module is left in an unpowered state for approximately 21 or more days, the battery will be completely drained
and the module BIOS, date, and time will revert to their default settings. Before you remove a module from its power
source, ensure the battery is fully charged. You can tell the battery is fully charged when the Battery State (ERR) LED
is OFF.
Note: The battery is not user-replaceable.