Battery for motor-assisted bicycle

The invention provides a motor-assisted bicycle having a removably mounted battery (1) along a frame of said bicycle. Said battery (1) has a battery meter (10) located in an upper portion of said battery (1) for externally indicating a remaining capacity of said battery (1) according to an output from an integrating means (84) of said battery meter (10) integrating electric energy charged and discharged for obtaining a value corresponding to the remaining capacity of said battery.