The use of a single small and discreet internal battery is light weight, efficient and creates a robust and reliable system One charge can give between 1000 and 2000 kilometre range depending on conditions and front mech operation (as this is the main power drain) 500 times rechargeable life Internal chip enables system wireless functionality of Bluetooth components Battery is to be mounted with seatpost or frame/fork manufactures hardware normally inside the seatpost or seat tube/fork steerer Reliable and secure water resistant E-tube terminals connection Charging is done via stem junction or handlebar display Battery weight is 50 grams .