I'm not sure the battery needs to be changed.

A small button-type battery is mounted internally and powers the H8000FW's memory
when the power is off. This should last about five years before it needs to be changed,
longer if the H8000FW is left powered up much of the time. The number of hours for
which the unit has been operating, powered and unpowered, can be found under
SETUP/service/information.
This battery should be replaced by a qualified technician only since it must be replaced
when the H8000FW is powered up in order to preserve the internal memory contents.
Contact your Eventide Service Center to have this battery replaced.

Use the box and see if anything weird happens in the next days….

best

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