SM-BCR1
Designed to charge the SM-BTR1 battery, the SHIMANO SM-BCR1 requires the appropriate SM-BCC1 cord (not included).
SM-BCR2
SM-BCR2 is for the charging of internal SHIMANO DI2 batteries (BT-DN110), the SM-BCR2 also serves as a PC linkage device for E-TUBE PROJECT firmware updates and settings.