Howdy @DarrenO505 ,
Bear with me! I’m digging up resources now, this may take a little time.
Just so you know, if you’re trying to do that “Martin Lewis Prepayment Trick/Hack”, please be advised that it won’t work. The meter will likely already have the next set of rates programmed by now and/or will do so as soon as you next top-up ready for the 1st October, or at very least OVO would know you’ve underpaid and charge you the difference anyway by placing a debt on the meter. The rates you have to pay are what’s on the account, not the meter.
Either way, OVO has options to salvage lost credit from broken meters. It’s 1,000% easier with Smart Meters, but may be possible with Traditional Prepayment too - it just takes more effort. If the salvage is successful, OVO’s policy is to restore the lost credit onto the replacement meter, but it can take a while in some cases.
With that being said… It may be worth upgrading to Smart Meters now anyway, not least so you get a fresh gas meter battery, but also so that your credit gets backed up to OVO’s systems every night. That way, if something happens, OVO can more accurately and more rapidly figure out how much credit to restore if needed.
@DarrenO505 From other comments I’ve seen on here the battery gives a warning some time before anything stops working but appreciate you are on PAYG which is an important flag to make sure that something is done sooner rather than later. @Blastoise186 is good with these things so he should make sure that you are dealt with in a timely manner.
Peter
Found it!
The reason behind what you were told is that OVO’s contractor won’t touch heritage meters with low batteries until they die. However, OVO can do a Smart Meter upgrade anyway regardless of how much battery is left so if you want a quick fix, that’d be the fastest option. It’s just the Emergency Meter Exchange option that’s locked out until the battery dies.
Let OVO Support know if you’re up for upgrading and they’ll make the arrangements. I’d recommend keeping the credit from building up too much between the time you book the upgrade and the time the meters are swapped, so that you reduce the risks of lost credit - just make sure to balance it with having enough to keep going!
And definitely drain the key/card onto the meters before the engineer arrives too!
Credit to a mysterious engineer...
See. Told you he would find a fix. He's so useful we've considered cloning him but we need to know where he lives but he seems to have developed a cloaking device.
At my last flat I had a pre-pay gas meter (non-smart) where the low battery warning came up.
I called British Gas and an engineer came and took a look, said it’s fine for years yet, and did nothing.
3 years later when I left that flat the meter was still working fine and still showing low battery.
So they do keep working for a long time even with a low battery.
The present location of Blastoise186 is: A Sekrit Underwater Lair somewhere on the Internet.
The present location of the user behind Blastoise186 is: Unknown. The user is an anonymous internet ghost and no-one knows where to find him.
Blastoise186 is the online username of a mysterious individual which has existed on the Internet for nearly 25 years. It is rumoured that Blastoise is his favourite Pokémon and that he has extensive knowledge of many things, alongside various skills that many consider mind boggling. It is also rumoured that he is a scuba diver, which is another reason behind his nickname Blastoise186.
The only things known about the user behind Blastoise186 is that he is a well known volunteer in a few different places and that he works in IT. No traces of the user have ever been found in the public domain. It would appear that he uses his online identity as his only public presence, in order to create an image of mystery and mischief.
I’m retired myself and like to help others. OVO just happen to provide a useful platform to aid that.
I don’t understand why anyone would react so negatively to anyone trying to give help to others.
FYI @BPLightlog, @Peter E & @Blastoise186,
I’ve removed the user from the Forum so you may see a few gaps in this conversation.
For anyone else reading - any abuse or harassment of our staff or volunteers will lead to your immediate removal from the Forum. This is a community that we should all be coming together and sharing helpful advice and knowledge.
You can find out more about our house rules here:
https://forum.ovoenergy.com/ovo-newbies-153/ovo-forum-community-guidelines-and-house-rules-7846
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If anyone has any questions or concerns please sent either myself or any of the moderators a message 
Hey @DarrenO505,
We recently met with one of our engineers and some of our volunteers. We learned that the engineering team has system alerts for low batteries. They can generally get to these before they power off, but if you have any concerns, you can ask for more support from our Customer Care team.
If you don’t get any further forward, we can ask our Forum engineer to take a look at this with you!
Keep us updated if you get this resolved. 
