Denso BHT-7000 User Manual page 35

Never charge the dry battery cartridge.
The BHT has an integrated backup power source which backs up the memory and
calendar clock in the BHT when no battery cartridge is loaded or the voltage level
of the battery cartridge drops below the specified level. The backup power source
is automatically charged by the battery cartridge.
When you first load the battery cartridge after purchase or you load it after leaving
the BHT unused for a long time, do not remove the battery cartridge for 10 minutes
or more after that loading. This is for charging the memory backup source
integrated in the BHT.
If you leave the BHT with no battery cartridge loaded for a long time, the memory
contents will no longer be backed up so that the message "Contact your administra-
tor. Note the error number. (XXXX)" or "Set the current date and time." may
appear on the LCD.
If you will not be using the BHT for a long time, follow the instructions given in
Subsection 2.4.4, "Battery Replacement Notes."
Avoid storing the battery cartridge in a hot place. The battery capacity may be
decreased.
Do not touch the charge terminals of the battery cartridge by hand or stain those
terminals. Doing so could result in a charging failure.
Checking the Battery Voltage Level
The battery voltage level is always displayed on the status indicator line.
(For details, refer to Subsection 2.4.3, "Adjusting the LCD Contrast & Beeper Volume
and Checking the Battery Voltage Level," [ 2 ].)
Chapter 2. Getting Started the BHT-7000 and System Mode
19