Patent attributes
A USB charger for an electronic cigarette includes a first interface, a control module and a second interface and a built-in battery. The control module is connected to the first interface, the second interface and the built-in battery respectively. The first interface is configured to connect an external power source so as to provide a power supply. The second interface is configured to connect a battery rod of an external electronic cigarette. The control module is configured to charge the battery rod of the electronic cigarette and the built-in battery simultaneously by using the external power source, or control the built-in battery to charge the battery rod of the electronic cigarette, based on the access state of the external power source at the first interface. The electronic cigarette can be charged by the USB charger even if there is no external power source.