Harry Bloomfield wrote:

Brian Gaff wrote:

many people with smart meters are told to change a battery in the gas bit.

The battery is not customer swappable.

Yes, I understood the supplier was responsible for changing the battery,
not the customer.

The battery is a long life one

This type
https://uk.rs-online.com/web/p/d-batteries/1835713/

I have no idea how the modern mechanism to record the flow works.

Mine uses ultrasonic time-of-flight measurement

https://youtu.be/vPc14g-b2YY?t=348