Just a side note; even if the battery is exhausted, the config will be still available on the file system.
The following symptoms will be seen after a power cycle (hard reboot):
It fails to boot with the secondary image even it is configured to reboot with the secondary image, instead it boots with the primary image.
The switch configuration becomes factory default.
When the “show switch” command is executed, the boot count is shown as 1, and the current year is shown as 1919.
If you then select the correct configuration file and reboot (soft reboot) you will be able to retrieve the configuration file and keep using the switch until the replacement is in place.