Yes, many modern number 9 lithium batteries have an automatic power off function. When the battery is fully charged, the internal protection circuit will automatically stop accepting the charge of the power supply, thus avoiding the case of overcharging the battery, protecting the life and safety of the battery. In addition, some No. 9 lithium batteries are also equipped with intelligent protection chips, which can monitor the voltage, temperature and other parameters of the battery, and can also cut off the power supply in time once the situation exceeds the safety range. Therefore, users can use the No. 9 lithium battery with confidence, but they must still follow the correct charging and use methods to ensure the normal function and safety of the battery.