Shimano Di2 Battery Charger You are looking at a Shimano Di2 Dura-Ace battery charger for external batteries. It Charges a Di2 battery in about one and a half hours. Whether you are charging the battery you are currently using or just juicing up a spare, it's always a good idea to have all your batteries topped off. Features Charges Shimano Di2 batteries Charge time: 1. 5 hours Charger cable is required for use (sold separately) | Shimano | Di2 Sm-Bcr1 Battery Charger Battery, Sm-Bcr1