Shimano Di2 Battery BT-DN300 Internal Built-in Type Compatible with EW-SD300 Di2 Wire

The Shimano Di2 DN300 internal built-In type battery. 3 ports for SD300 series wires. Works with most Shimano 12-speed road derailleurs and shifters. Compatible SD300 wires and systems after R9250/R8150 series. Li-Ion 500 mAH / 3.7 Wh (± 2000 km autonomy). 7.4 volts. Charges through RD-R9250/RD-R8150 rear derailleur using EW-EC300 Di2 charging cable (sold separately.)