Siemens S5-155U System Manual page 213

377 Memory Submodules
Submodules with battery
backup
5 - 64
Current consumption 140 mA max.
(at 5 V)
13 µA typ.
Backup current
Backup voltage/ 2.7 to 3.6 V
UCMOS
Submodule battery Lithium button cell 3 V/200 mAh
Type CR 2430 (LF-1/2W) from VARTA
Backup time 1 year min. at 25
Access time t 150 ns
ACC
o
C
System Manual
C79000-B8576-C199-03