Shimano BT-DN300 Built-In DI2 Battery
Introducing Shimano BT-DN300 Built-In DI2 Battery: Part of the Shimano Di2 Battery system. To create a complete setup, you'll need the battery, charger, and power cable. It's crucial to ensure that all Di2 components on your bike run the same firmware version, as mismatched versions can lead to issues. Utilize the Di2 system checker to conveniently update component firmware via http://e-tubeproject.shimano.com/.
For Dura-Ace 9150 and Ultegra R8150 Systems.