@Maxie_b The smart meters have buttons which you have to press to get a reading. The serial number of your meter will be printed on it, make a note and telephone or email it to SP. email@example.com.
@Gengis Only gas meters have batteries, it could be that your screen is blank because you have not pressed the button on the gas meter to wake it up. Display units have a battery also but they are normally left plugged in to a power supply.