Is the handheld inner diameter measuring device powered by power supply or battery?

I don't know, if it is directly powered, it can be continuously measured, but it is definitely inconvenient to connect the inner diameter measuring instrument with wires at the scene. Although battery power supply is not so complicated for wiring and electrification, it will take some time to charge. If the battery can withstand manufacturing, it will be very big. The existing ZID 100-HH series hand-held internal diameter measuring instrument in Britain is powered by 6400 mAh lithium battery, which can measure at least 1500 times at a time.