Shimano Ultegra ST-6870 Dealer's Manual page 64

CHARGING THE BATTERY
Charging method
Built-in (SM-BCR2 / SM-BTR2)
Example of connection for charging
(A)
To an AC adapter with a USB port or PC
Connect the battery to the junction (A) or information display.
1
Connect the charging cable of the charger to the junction (A) or the charge port of the
information display.
2
When the CHARGE indicator (orange) goes out, charging is completed.
3
4
Disconnect the charging cable or USB cable, and keep it at the location specified in the
precautions.
(A)
64
(A)
Charging port
The position of the charging port differs
depending on the product.
You can charge the battery by using the AC
adapter with a USB port or connecting the
battery charger to a PC USB port.
The charging time of an AC adapter with a
USB port is about 1.5 hours, and that of PC
USB port type about 3 hours. (Note that the
actual time will vary depending on the
amount of charge remaining in the battery.)
Depending on the specifications of the AC
adapter, recharging via the AC adapter
requires as many hours (about 3 hours) as
recharging via PC.
If ERROR indicator or CHARGE indicator
blinks, refer to "Troubleshooting for charging
error".