UK ISP BT Criticised Over Failure of Broadband Battery Backup During Power Cuts

Broadband provider BT (EE) has been criticised by a resident of the remote Outer Hebrides (Scotland) island of Scalpay after they found that the Battery Backup (BBU) device, which the ISP provided for their internet and Digital Voice (phone) service, failed to work in two out of three recent power cuts. A bit of a problem as the house also gets no mobile signal.

The need for a BBU is relevant because the industry is now in the final process of retiring legacy phone services (PSTN/WLR) by 31st January 2027 (details). But one key advantage of the old method was that copper phone lines could be powered from an exchange, thus BBU’s were not usually required. Sadly this is not possible with most modern internet-based digital phone equivalents (especially if fibre optic FTTP lines are involved as these cannot carry electricity).

Internet and phone providers like BT thus optionally provide a BBU to “vulnerable customers” (usually for free) who have taken their IP-based Digital Voice (phone) services. The BBU is designed to ensure that the customer’s router and optical modem (ONT) still works when there’s a power cut, which means they’re able to make an emergency call using an existing handset. Regular customers can also get one of these, albeit for an additional cost.

However, in the aforementioned case on Scalpay, Jane Roberts and her husband said (Stornoway Gazette): “There have been three power cuts recently and the broadband has only worked in one of them. It’s leaving no communication for emergency services … BT and their new digital voice system are going to be responsible for possible fatalities in the future when they are predicting everyone will be on it by the end of 2027.”

According to Jane, BT’s BBU system failed during the first power cut, had worked during the second power cut – on Boxing Day – and then failed again on the third, which came just 20 minutes after the second power cut. We assume the system in this case is setup correctly, since it did at least work on one of those occasions, but it’s hard to tell with so little detail and only some very anecdotal feedback from one user.

A BT spokesperson said:

“UK landline providers are switching from analogue to digital services, as the old technology is increasingly unreliable and no longer fit for purpose.

We recognise the concerns raised and encourage any customers experiencing issues to contact us directly so we can review their setup and provide a tailored solution. At BT, keeping customers connected is our top priority and we remain committed to supporting vulnerable customers through the switch.”

Sadly, the article doesn’t provide any solid details to help us examine the circumstances around this case, such as precisely which BBU unit Jane has (BT supply two different solutions), what her setup looks like or how long the power cuts lasted etc. BT’s latest BBU Plus kit (pictured) launched last year alongside other providers (Vodafone, Zen Internet and KCOM) and is designed to last for 4 hours (here), before going into an idle mode that reserves just enough power for an emergency call.

The article suggests that Jane had switched to the new Digital Voice service late last year, and so we assume her home would have been provided with the latest BBU Plus kit. But obviously if any of the power cuts lasted longer than 4 hours then that might become a problem. In addition, if any of those power cuts also impacted BT / Openreach’s wider network, then it wouldn’t matter if the BBU itself was working or not as there’d be no connectivity either way (not even an old legacy phone would have worked in that circumstance).

Suffice to say that more detail and context is required in order to properly assess what actually caused the system not to work, which is important because many other people will be installing similar systems and expecting it to work.

In the meantime, consumers can of course optionally buy a larger portable power station [affiliate link] online for more money, but we recommend only getting one that uses a LiFePO4 battery, as they last longer and are better at holding a charge. However, if you have deeper pockets and also want to save money on your electricity bills, then a whole-home solution (e.g. GivEnergy, Tesla Powerwall etc.) that charges up at cheaper off-peak rates could be another option, but the latter does tend to cost several thousand pounds.

Otherwise, the move away from the old legacy phone network is a somewhat unavoidable change, due both to the roll-out of full fibre connections and the fact that the legacy phone network is now rapidly reaching “end of life“; it’s already becoming unreliable and sourcing replacement hardware when parts fail is difficult. Suffice to say that the change isn’t going to be reversed, so it’s now much more important to consider having a backup.