Bicycle Light, USB Rechargeable
1. Check the battery: Make sure the battery has electricity and install the battery in the correct direction. Do not use batteries of different brands. The old and new batteries should not be mixed.
2. Check the tail cover: Make sure that the switch is tightened and the contact is good, to ensure that the copper column of the tail cover and the metal plate of the tail cover are in good contact, pay attention to whether the lamp head is loose.