Using this 18650 battery charger case is a breeze. Just open the spring - clip design and gently place your 2 x 3.7V 18650 batteries inside. When it comes to installation, you can use the 3mm fixing holes to secure it in place. As for maintenance, keep it in a dry and cool place to prevent any damage to the ABS + metal material. Avoid exposing it to extreme temperatures. If the wires get dirty, you can gently wipe them with a dry cloth. Always ensure the batteries are properly inserted to avoid any short - circuits. Enjoy using your new battery charger case!