Replacing The Battery; Purpose Of The Battery; Battery Service Life And Replacement Period - Omron NJ501-1 Series User Manual

6 Inspection and Maintenance
6-2

Replacing the Battery

The Battery in the NJ-series CPU Unit must be replaced periodically as preventative maintenance. (The
Battery is a backup power supply for the CPU Unit's internal clock and the variables that are retained
during power interruptions.) This section describes how to replace the Battery.
6-2-1 Battery Replacement

Purpose of the Battery

The Battery maintains the CPU Unit internal clock and the variables retained during power interruptions
while the main power supply is OFF. If the Battery is not installed or Battery voltage drops too low, the
internal clock will stop and the variables that are retained for power interruptions will be lost when the
main power supply goes OFF.

Battery Service Life and Replacement Period

Model
NJ501-
NJ301-
* The minimum lifetime is the memory backup time at an ambient temperature of 55C. The typical lifetime is the
memory backup time at an ambient temperature of 25C.
Memory Backup Time
5 yr
4 yr
3 yr
2 yr
1 yr
6-4
Approx. maximum
lifetime
5 years
5 years
NJ501- CPU Unit
25°C 40°C
* This graphic is for reference only.
Approx. minimum lifetime
1.1 years
2 years
NJ301- CPU Unit
Ambient temperature
55°C
NJ-series CPU Unit Hardware User's Manual (W500)
*
Approx. typical lifetime
5 years
5 years
*