[c-nsp] Replace NVRAMBattery - decrease impact

["Rolf Hanßen"]

Hello,

I just saw that here on a 6509-E + Sup2T:

router#show diagnostic result module 5
...
  51) TestNVRAMBatteryMonitor ---------> F
...

>From my understanding this means battery is empty and I need to replace
the button cell.
Correct?

Afair replacing it means nvram is lost and needs to be re-formatted +
files copied back to it.
Is there a way to bypass this and to reduce downtime in case of a single sup?
Can I replace the battery during operation or does that have some
side-effects (in case I avoid a short-circuit by touching something)?

kind regards
Rolf