Shimano GRX RX 815 Series Dealer's Manual page 136

CHARGING THE BATTERY
Built-in type
2.
Connect the plug for product connection on the battery charger to the
charging port on the product.
The position of the charging port differs depending on the product. Insert it in firmly as
far as it will go.
Charging starts and the charge indicator lights up. When the charge indicator turns off,
charging is complete.
Charging port
Plug for product
connection
Charge indicator
On: Charging
Off: Charging complete
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