Shimano SM-BCR2 is a corded battery charger and PC linkage device for Shimano Di2 electronic shifting systems. It is intended for Shimano lithium-ion batteries such as SM-BTR2, and Shimano’s product documentation also lists support for BT-DN110/BT-DN110-A in the Di2 system lineup. It connects by USB for charging and for E-TUBE PROJECT firmware updates and settings, making it useful for riders who want one unit for both battery charging and drivetrain setup. The charger is compact, lightweight, and designed for indoor use. Key specifications in the manual include 5.0 V DC input, 8.4 V DC output, and an approximate weight of 70 g excluding the USB cable.