These are powered directly from your electricity supply. In case of power interruption, your smart meter will save your information (including your IHD information), so that it can be restored when the power is back.
These are powered by a battery that’s built into the meter, due to safety reasons you won’t be able to access it. The battery is designed to last over 10 years before a replacement is required and when it is, the gas meter will alert our systems. When this happens, we will contact you to arrange an appointment to replace the battery.