The 17 BMW 7 Series LCD keys are rechargeable. The charging method is very simple, first find the charging interface on the key, usually located at the bottom of the key. Then use the accompanying charging cable to connect the key to the power supply, either using a USB port or a charger.
When charging, the indicator light on the key will light up, indicating that it is charging. The charging time is generally 1-2 hours, and the indicator light will be extinguished after it is full. Regular charging is recommended to keep the key in normal use.