The Shimano DN300 Di2 Internal Mount 3-Port Battery is the powerhouse of Shimano Di2. A long-life 7.4V Li-Ion battery that is both compact and reliable, taking shifting effort away from you.Shimano DN300 Di2 Internal Mount 3-Port Battery FeaturesExcellent sealing and reliability have been proven through repeated field tests in various riding conditions, including extreme temperatures, rain, mud, and cobblestone roadsThe use of a single small and discreet internal battery is lightweight, efficient and creates a robust and reliable systemOne charge gives a 1000 kilometre range depending on conditions and front mech operation (as this is the main power drain)500 times rechargeable lifeBattery is to be mounted with seatpost or frame/fork manufactures hardware normally inside the seatpost or seat tube/fork steererReliable and secure water resistant SD300 E-tube terminals connectionCharging is done via stem junction or handlebar displayBattery weight: 50 grams7.4V lithium-ion / 3-ports for SD300 wires