How do you view the current usage and life of the iPhone battery? Will there be a problem if you don't update the ios phone?

It doesn't matter if you don't update the system. It is suggested that the old equipment does not need to be updated to the latest version of the system, just update the big version once or twice, otherwise it will get stuck.

You can use PP Assistant to check the battery life of the device. After the computer is downloaded and installed, the device will be connected. If iTunes is not available, it will be downloaded and installed automatically. After the device identification is successful, you can see the specific device information in the main interface, and you can also see the hardware detection on the mobile phone PP.