[fintstone]

If you have a battery fault, your battery backup is most likely not working anyways. Even if you disconnect power briefly, it will likely just see it as a temporary loss from the power line (like a brownout). I have done this quite a few times myself without problem. Unless you are securing the crown jewels, it is unlikely your system is spohisticated enough to care (intentionally)...to prevent false failure.

Still...be stealthy and be prepared to disavow knowledge if necessary as noted above.