Comtech EF Data SMS-758 - Manual (Page 118)

Maintenance SMS-758 Modem Protection Switch
5–6 MN/SMS758 Rev. 3
5.2.4 Battery
Faults Procedures
M&C BATTERY FAULT
(M&C_BAT_FLT) Check the position of the internal battery jumper on the M&C
board.
Check the battery for bent or displaced leads.
The NiCad battery on the M&C board is rechargeable and may
require up to 48 hrs. to fully charge.