What happens when the battery in the gas smart meter starts to fail?

  • WizzyWigg's Avatar
    Level 87
    My gas smart meter is sending erratic readings to the DCC. All the rest is fine. What I would like to know is if the battery starts to fail are there any audible or visible indications from the meter and should it fail completely does it fail to off? Hence totally cut the gas supply off? Any information and help on this subject would be much appreciated. Including contact procedures and speed of rectification.
  • 9 Replies

  • Best Answer

    retrotecchie's Avatar
    Level 92
    Best Answer
    @WizzyWigg

    Depending on the make and model of your gas meter, various things can happen, but the general principle is as follows:

    Gas meters have two power sources. The main lithium battery, which should last for around ten years, or the certification life of the meter, and a 'supercapacitor' which is charged up at the factory and has it's charge maintained by the internal battery. By their very nature, having to transmit bursts of data to the comms hub at regular intervals, batteries on smart meters rarely last the full ten years.

    The display on your meter is usually blank to save power. The metering system itself uses very little battery power, but operating the display doubles the drain on the battery. To read your meter, you have to press a button to 'wake' the electronics and activate the display. In most cases, when you wake the meter you will see the meter reading displayed and after a few seconds, the display will then blank again to save power.

    If while the display is live, you press the button again it is often possible to scroll through multiple screens, one which will usually indicate battery status.

    With some gas meters, once the battery drops below a set value the meter may sound an alarm. This will be very similar to a battery operated smoke alarm in that it gives a very short 'beep' every so often to indicate the battery is getting low. Other meters will display a battery error message on the display when you try to read the meter. Very hard to spot if your meter is outdoors in a meter hutch, or in the garage.

    Now, when the battery gets below the threshold, it will no longer be able to transmit data or even operate the display, but the supercapacitor continues to power the internal metering electronics so the meter maintains an internal record of gas consumed.

    Certain models of meter have a cover, locked with a lead seal like an electricity meter, which can be opened by an engineer and the battery replaced in situ. In this instance, as soon as the battery is replaced, the display and data transmission system becomes available again, and the internal measurement is then accessible again in the usual way. Other meters have an internal battery that can only be accessed by disassembling the meter on a bench. In this case, the meter is usually swapped for a whole new unit. Once the old meter has been returned to base, the internal data can be read and an accurate reading taken to update your records.

    The caveat here is that once the main battery has failed, the supercapacitor can usually only keep the meter internals alive for perhaps a month. So, if you don't spot the low battery and let the meter carry on, chances are it will fail completely. The daft thing is that the meters actually send low battery warnings to the smart network as an 'alert' message, but these are rarely actioned by suppliers. Usually, the user has to keep an eye on the meter and report a failing battery manually.

    Had I designed the system, I would have also put a gas meter battery status or warning on the IHD itself. Maybe this does happen or there is a way to check gas meter battery status from the IHD? I don't know as I don't have gas or any kind of smart meter. I know the status message is part of the SMETS specification, but whether it has been properly implemented or not, I have no idea.

    But that's how things work, from my delving into such things. As far as I am aware, smart credit meters will not cut off your supply, but if the battery fails and nothing is done before the supercapacitor dies, then the last available reading is written to flash memory in the meter and that's it. Any further consumption can only be estimated.


    Last edited by retrotecchie; 15-01-23 at 11:01.
    Don't shoot me, I'm only the piano player. I DON'T work for or on behalf of EON.Next, but am willing to try and help if I can. Not on mains gas, mobile network or mains drainage. House heated almost entirely by baby dragons.
  • WizzyWigg's Avatar
    Level 87
    @WizzyWigg

    Depending on the make and model of your gas meter, various things can happen, but the general principle is as follows:

    Gas meters have two power sources. The main lithium battery, which should last for around ten years, or the certification life of the meter, and a 'supercapacitor' which is charged up at the factory and has it's charge maintained by the internal battery. By their very nature, having to transmit bursts of data to the comms hub at regular intervals, batteries on smart meters rarely last the full ten years.

    The display on your meter is usually blank to save power. The metering system itself uses very little battery power, but operating the display doubles the drain on the battery. To read your meter, you have to press a button to 'wake' the electronics and activate the display. In most cases, when you wake the meter you will see the meter reading displayed and after a few seconds, the display will then blank again to save power.

    If while the display is live, you press the button again it is often possible to scroll through multiple screens, one which will usually indicate battery status.

    With some gas meters, once the battery drops below a set value the meter may sound an alarm. This will be very similar to a battery operated smoke alarm in that it gives a very short 'beep' every so often to indicate the battery is getting low. Other meters will display a battery error message on the display when you try to read the meter. Very hard to spot if your meter is outdoors in a meter hutch, or in the garage.

    Now, when the battery gets below the threshold, it will no longer be able to transmit data or even operate the display, but the supercapacitor continues to power the internal metering electronics so the meter maintains an internal record of gas consumed.

    Certain models of meter have a cover, locked with a lead seal like an electricity meter, which can be opened by an engineer and the battery replaced in situ. In this instance, as soon as the battery is replaced, the display and data transmission system becomes available again, and the internal measurement is then accessible again in the usual way. Other meters have an internal battery that can only be accessed by disassembling the meter on a bench. In this case, the meter is usually swapped for a whole new unit. Once the old meter has been returned to base, the internal data can be read and an accurate reading taken to update your records.

    The caveat here is that once the main battery has failed, the supercapacitor can usually only keep the meter internals alive for perhaps a month. So, if you don't spot the low battery and let the meter carry on, chances are it will fail completely. The daft thing is that the meters actually send low battery warnings to the smart network as an 'alert' message, but these are rarely actioned by suppliers. Usually, the user has to keep an eye on the meter and report a failing battery manually.

    Had I designed the system, I would have also put a gas meter battery status or warning on the IHD itself. Maybe this does happen or there is a way to check gas meter battery status from the IHD? I don't know as I don't have gas or any kind of smart meter. I know the status message is part of the SMETS specification, but whether it has been properly implemented or not, I have no idea.

    But that's how things work, from my delving into such things. As far as I am aware, smart credit meters will not cut off your supply, but if the battery fails and nothing is done before the supercapacitor dies, then the last available reading is written to flash memory in the meter and that's it. Any further consumption can only be estimated.

    Thank you so much for your in depth information. If I was to upload a photo of the meter could you be more specific? Also would you say that a battery issue could generate these erratic reading to the DCC?
    Kind regards
  • Tommysgirl's Avatar
    Guest
    @WizzyWigg
    You usually get a low battery warning message on the meter, but not always. When the battery on my gas meter died, I didn't get any prior warning, the screen went blank and it stopped sending readings to Npower (who were my supplier before they were taken over by Eon-Next). Don't worry, your gas supply continues as normal, but you will need to contact Eon-Next immediately to arrange an engineer visit, otherwise you will be stuck with estimated bills until they sort it. They will most likely have to install a new meter, that's what Npower did with mine. NPower replaced my meter within a few days of my contacting them, but I don't know what the timescale will be with Eon-Next. If you ring them, be prepared to be held in a queue for about an hour, it's usually best to try early at 9am, as they get busier as the day goes on. If they cannot pull a reading for the time your meter is out of action they will make an estimate based on your previous usage. Hope this helps.😃
  • retrotecchie's Avatar
    Level 92
    Thank you so much for your in depth information. If I was to upload a photo of the meter could you be more specific? Also would you say that a battery issue could generate these erratic reading to the DCC?
    Kind regards

    Yes, a picture of your meter might give me a few more clues.
    A battery issue could potentially cause reading issues but from what I have seen, smart gas meters are 'erratic' at the best of times. Sometimes the hub misses the data burst from the meter itself but more often than not it's related to communications between DCC and the supplier, or something amiss on the supplier side.

    Personally, the whole implementation of the smart metering system has been very poorly thought out, in my opinion, and smart gas meters seem to give more headaches to suppliers and consumers than they could ever make up for in any so-called benefit to the end user.

    As an electronics engineer and systems designer for many years, I can easily look at the system and say to myself 'I would have done it differently'. Just because new technology exists doesn't mean it has to be used.

    The really upsetting thing is that someone did indeed come up with a much better way of doing it, has a set of patents for such a system and actually won a Queens Award for Industry for the concept, but the system was over-ruled in favour of the pile of steaming horse doings we have now, thanks to the European Union. As we are no longer in the EU...
  • WizzyWigg's Avatar
    Level 87
    Yes, a picture of your meter might give me a few more clues.
    A battery issue could potentially cause reading issues but from what I have seen, smart gas meters are 'erratic' at the best of times. Sometimes the hub misses the data burst from the meter itself but more often than not it's related to communications between DCC and the supplier, or something amiss on the supplier side.

    Personally, the whole implementation of the smart metering system has been very poorly thought out, in my opinion, and smart gas meters seem to give more headaches to suppliers and consumers than they could ever make up for in any so-called benefit to the end user.

    As an electronics engineer and systems designer for many years, I can easily look at the system and say to myself 'I would have done it differently'. Just because new technology exists doesn't mean it has to be used.

    The really upsetting thing is that someone did indeed come up with a much better way of doing it, has a set of patents for such a system and actually won a Queens Award for Industry for the concept, but the system was over-ruled in favour of the pile of steaming horse doings we have now, thanks to the European Union. As we are no longer in the EU...
    You've summed up the problem with most pieces of equipment. The lack of thought into the long term issues. Anyway thanks again for your help. I enclose a photo of afore mentioned meter.

    Kind regards
    Attached Images Attached Images  
  • retrotecchie's Avatar
    Level 92
    That meter should beep occasionally when the battery gets low. In theory it has a field replaceable battery, but many outfits just swap the meter as they don't have the correct tool for accessing the battery compartment. The cover is the bit with the yellow sticker on it. There should be a way of user-accessing the battery status, but I can't seem to find it with my limited searches.

  • WizzyWigg's Avatar
    Level 87
    That meter should beep occasionally when the battery gets low. In theory it has a field replaceable battery, but many outfits just swap the meter as they don't have the correct tool for accessing the battery compartment. The cover is the bit with the yellow sticker on it. There should be a way of user-accessing the battery status, but I can't seem to find it with my limited searches.
    Brilliant. Thank you so much for all your help.