The battery and controller are both mounted within the frame, but the key feature of this product is that the battery can be easily removed, allowing users to take it home for convenient charging. This design complies with the latest EN standard. The compact size of the battery makes it particularly popular for city and commuter bikes, often leading people to mistake it for part of the bike itself. With a maximum capacity of 360Wh using Samsung 21700 cells, the battery has been certified to EN50604, ensuring high standards of performance and safety.