Where do Smart Gas Meters get the electricity to run their circuitry from?

Does anyone know the answer to this?
It’s a mystery to me - I can guess where my “smart” electricity meter gets it’s power from,
but where does my “smart” gas meter get the electricity to run an on board micro-controller, an LCD display, a beeper and a 2.4ghz radio transceiver?
there are no electrical wires going in to the gas meter that I can see.

I believe it is battery.

Thanks - Good to know - I’m surprised that’s considered reliable enough.
They’ll probably be replaced by another form of meter before the battery needs replacing though!

@Chris_222 and @scudo, smart electricity meters get the power to run from the consumer side of the meter (so you will be paying a couple of quid a year for the pleasure of automated readings and the other fancy things that come along with it).

Smart gas meters run off a battery like existing digital gas meters do, and then they communicate via a low power wireless link to the electricity meter. I believe the batteries are long life lithium ones (not rechargeable li-ion, just lithium) which should last a good number of years. The display is also normally off most of the time on them to conserve energy and the wireless radios only communicate periodically.

The meters should also be able to communicate with your energy supplier when the battery is running low and then I presume the people who used to be meter reading engineers will become battery replacement engineers :wink:

@Chris_222@mowcius is right. They are powered by a battery that should last for about 15 years. The meter will wake up every 30 mins and send a reading to the Communications Hub.