Denso BHT-400B-CE - Manual (Page 54)

2.3.4 BHT Turning-off Notes
[ 1 ] "Shutdown in progress" message
If you press the power key to turn off the BHT, the BHT displays the following message and starts
preparation for shutdown.
When the above message is displayed, do not remove the battery cartridge.
If you do so, the data stored in the BHT may be lost.
34