Denso BTH-300BW User Manual page 180

Charging Operation and LED Indication
Operator's Action
Place the BHT on the CU-300.
⇓
After approx. 3 hours
(approx. 9 hours)*
⇓
Remove the BHT.
*When the CU-321 is powered from the USB host (computer) or USB hub.
If the CU-321 is self-powered via the USB interface from the USB host (computer) or USB hub and the
host computer is in suspend mode, then the CU-321 cannot charge the battery cartridge.
If the host computer switches to the suspend mode when the CU-321 is charging the battery cartridge,
then the CU-321 will stop charging. When the host computer recovers from the suspend mode, the
CU-321 will start charging again. To prevent the CU-321 from getting affected by the suspend mode,
use the dedicated AC adapter.
CU-300 Status
On standby
⇓
Normal charging
⇓
Charging completed
⇓
On standby
165
Chapter 5 Handling the CU-300 (Option)
Indicator LED on the BHT
OFF
ON (in red)
ON (in green)
OFF