Changing pre tension seat belts

[Waders]

Hi guys
I am changing all five rear seat belts on a 06 mercedes e280 Estate. Question is will just disconnecting the main battery not secondary battery be ok or does disconnecting secondary battery need to happen also if so what problems could the cause. I know I would have to to leave to power down for ten mins before removing belts. Any help much appreciated. Thanks

 

[00slk]

I have never disconnected batteries when changing seatbelts, or airbags for that matter.
Though I would recommend disconnecting both batteries. There should be no issues when finished and both batteries reconnected. You will have to reset the windows though

 

[Waders]

Thank you