Shimano Di2 Batteries. Must purchase battery, charger, and power cable to complete the system. All Di2 components on the bicycle require the same firmware version. Using Di2 components with different firmware versions may cause malfunctions. Di2 External Battery, battery charger, and power cable are universal between Dura-Ace 9070, 7970, Ultegra 6870, 6770 and Alfine Di2 systems. Battery weighs 71g.
Shimano SM BTR1 Di2 External Battery
Shimano Di2 SM-BTR1A Universal Battery [ISMBTR1A]
Shimano Di2 SM-BTR1A Universal Battery [ISMBTR1A]
Shimano Di2 SM-BTR1 External Battery
Shimano SM-BTR1 Di2 External Battery - Performance Bicycle
Shimano Dura-Ace Di2 Battery : Sports & Outdoors
Shimano SM-BTR1 Di2 External Battery - Performance Bicycle
SM-BTR1 SHIMANO BIKE-EU
SHIMANO(シマノ) SM-BTR1-A SM-BTR1-A
Shimano SM-BTR1 Di2 External Battery - La Bicicletta Toronto
SHIMANO(シマノ) SM-BTR1-A SM-BTR1-A
Texas Cyclesport Shimano SM-BTR1 Di2 Battery, External System SM-BTR1 60.99 New
Universal Cycles -- Shimano SM-BTR1 E-Tube Di2 External Battery [ISMBTR1A]
Shimano Di2 SM-BTR1 External Battery