Power supply for electric bikes

The present invention includes a plurality of bare cell and the protection circuit module, the case that electrically is electrically connected to the battery pack, the battery pack is connected to receive a key box and the battery pack and the key box which is ON / OFF control, The key box in accordance with an operation of an inserted key is moved through the axis the key cylinder is moved to the front or back formed to be close to the received set of keys, the key cylinder, each additional contact terminal, wherein the connecting portion is connected to the other polarity is formed ON / OFF that it is included the terminal base and the key box case in which the key set, the contact terminal and the terminal base is acceptable including a terminal block which is removable so that the control, the terminal base is plate-shaped, outer peripheral surface of the plate is formed in a polygonal key for electric bicycles, characterized in that worked and formed to the inner box case relates to a power supply.