Siemens Simatic RTU303xC Series Operating Instructions Manual page 175

To change the batteries, you first need to disconnect the battery module being used in the
configuration. Follow these steps:
1. In the WBM, open the page. "Power supply".
2. Disconnect the battery module currently being used in the parameter group. "Battery
module 1" / "Battery module 2".
3. Shut down the RTU to the safe status if you only use a single battery module (including
any expansion modules) and no external power supply. See section Operating status
(Page 127) for information on this.
If you use two battery modules or an external power supply, skip this point.
4. Open the battery module whose battery you want to change.
For a battery change you do not need to separate the battery module from the RTU and
do not need to take it from the DIN rail.
Lift up the cover on the front of the module. To ensure a secure grip, there is a recess on
the right-hand underside.
5. Pull the connector of the battery holder and remove the battery holder from the battery
module.
6. Change the batteries and place the battery holder back in the battery module.
7. Plug the connector of the battery holder in the correct position in the socket
X10 BATTERY of the battery module. To protect against voltage reversal, the connector
is coded.
8. Close the battery module.
9. Finally, connect the battery module in the WBM on the page "Power supply", see above.
Note the information on handling used batteries in the section Batteries: Replacement,
recycling and disposal (Page 332).
RTU303xC
Operating Instructions, 06/2019, C79000-G8976-C382-06
NOTICE
Remove the battery only after disconnecting
Pull the connector of the battery holder in the battery module only when the battery is
displayed as "disconnected" in the WBM.
NOTICE
Do not place the battery holders on a conductive surface.
Never place the battery holders on an electrically conductive surface (e.g. the outer
housing).
The battery contacts can establish a short-circuit connection in the battery via a
conductive surface. This can destroy the battery.
Configuration (WBM)
4.18 Operating mode
175