The Shimano BT-DN110 is an internal rechargeable lithium-ion battery designed specifically for Shimano Di2 electronic shifting systems. Its compact cylindrical shape (Ø17 mm x 160 mm) allows it to be mounted internally on road and mountain bikes, typically inside the seatpost or frame, which keeps the bike’s aesthetics clean and allows for a secure fit. It provides 7.4 volts at 0.5 Ah (3.7 Wh) capacity, enabling long use between charges—up to approximately 2,000 km depending on conditions.

This battery is waterproof and built to withstand outdoor cycling environments, making it suitable for road, mountain, and indoor/outdoor use. Compatible with Shimano Di2 systems including Alfine, Nexus, Dura-Ace R9150, Ultegra 6870, Deore XT M8050, and more, it connects via the E-Tube system and charges through the SM-BCR2 charger using the SM-EW90 Junction Box, eliminating the need to remove it for charging. External mounting is possible with an additional bracket (SM-BTC1) if internal installation is not feasible.