User`s manual

Battery life and replacement procedure Maintenance and inspection
MELSEC System Q, Hardware 10 – 5
Battery Q6BAT
● Q00JCPU, Q00CPU and Q01CPU

The power-on time ratio indicates the ratio of programmable controller power-on time to one day (24 hours).
When the total power-on time is 12 hours and the total power-off time is 12 hours, the power-on time ratio is
50 %.

The guaranteed value represents a battery life at 70 °C, which is calculated based on the characteristic values of
manufacturer-supplied memories (SRAM) and on the assumption of storage within the ambient temperature
range of –25 °C to 75 °C (operating ambient temperature of 0 °C to 55 °C).

The actual service value (reference value) represents a battery life that is calculated based on the values meas-
ured at storage ambient temperature of 40 °C. This value is intended for reference only, as it varies with charac-
teristics of the memory.

In the following status, the backup time after power off is 3 minutes:
– The battery connector is disconnected.
– The lead wire of the battery is broken.
CPU
Power-on
time ratio

Battery life (Q6BAT)
Guaranteed value

Actual service value

After SM52 turned on

Q00JCPU
Q00CPU
0 % 26000 hours
(2.96 years)
43800 hours
(5 years)
710 hours (30 days)
30 % 37142 hours
(4.23 years)
50 % 43800 hours
(5 years)
70 %
100 %
Q01CPU 0 % 5600 hours
(0.63 years)
25175 hours
(2.87 years)
420 hours (18 days)
30 % 8000 hours
(0.91 years)
35964 hours
(4.10 years)
50 % 11200 hours
(1.27 years)
43800 hours
(5 years)
70 % 18666 hours
(2.13 years)
100 % 43800 hours
(5 years)
Tab. 10-6: Battery (Q6BAT) lives of Q00JCPU, Q00CPU or Q01CPU