The present application discloses a battery assembly, an electronic cigarette using the battery assembly, and a method for assembling the battery assembly. The battery assembly is configured to be connected with an atomizing assembly to form the electronic cigarette. The battery assembly comprises a battery sleeve, a battery, an end cover, a control module, and an electronic wire. The end cover defines an assembling hole configured to mount the control module therein, and the end cover further defines at least one wire holding groove in an inner wall of the assembling hole and configured to enable the electronic wire to pass through. The wire holding groove can effectively prevent the electronic wire from being squeezed and scraped by the battery sleeve and the end cover. Open-circuit and short-circuit of the circuit in the battery assembly can be avoided, and the product quality of the battery assembly can be improved.
