Buying guide
Mini UPS for a Wi-Fi router
Mini UPS units are small, cheap and everywhere online. Some work brilliantly. Many don't fit UK hubs at all. Here's how to tell.
On this page
The voltage trap
Lots of mini UPS units are sold for 5V or 9V devices. UK broadband hubs are almost always 12V. Using the wrong output won't power the hub, and could damage it.
The plug trap
Hubs use different barrel plug sizes. A unit with no adapter tips may not fit, even if the voltage is right.
LineKeeper™ Hub Battery Backup
4+ hours of backup · fits in 60 seconds · free UK delivery · 90-day money-back
From £89
Fibre box and hub together
If you have a separate fibre box, you need 2 outputs or a splitter. Many mini UPS units only have 1 at 12V.
Made for UK hubs
LineKeeper is a 12V hub battery backup with adapter tips and a splitter lead for UK hubs and fibre boxes, 4+ hours of runtime, UK customer support and free UK delivery.
How long will the backup last?
LineKeeper has a 74 Wh battery. A typical UK broadband hub uses roughly 10 to 15 watts, which gives 4 hours or more. Powering a separate fibre box as well, or an older hub that uses more power, shortens that. Fewer connected devices make it last longer.
For comparison, providers only have to offer a solution that lasts at least 1 hour. Many UK power cuts, especially in storms, last longer than that.
| What LineKeeper is powering | Typical runtime |
|---|---|
| Modern broadband hub only | 4+ hours |
| Hub plus separate fibre box | Less than hub alone |
| Older or high-power hub | Less than 4 hours |
| Provider minimum (Ofcom guidance) | 1 hour |
Is LineKeeper right for your home?
It's a good fit if: your phone now plugs into your broadband hub; someone at home relies on the landline or a pendant alarm; mobile signal is weak where you live; or you buy for a parent who lives alone.
It's not the right fit if: your hub's plug label doesn't say 12V; you need to power a computer, TV or fridge (LineKeeper is made only for hubs and fibre boxes); or your alarm already has its own mobile (SIM) connection and you don't use the landline.
Not sure? Try it for up to 90 days. If it doesn't suit you, send it back for a full refund.
How to fit it, step by step
- Charge it. Plug LineKeeper into the mains and let it charge fully. It stays plugged in from then on.
- Check the plug label. Look at the label on your hub's power plug. If it says 12V, LineKeeper fits.
- Connect the hub. Unplug the hub's power lead from the hub, plug it into LineKeeper, then plug LineKeeper's output lead into the hub.
- Add the fibre box if you have one. If a separate white Openreach box on the wall also has a power lead, use the splitter lead in the box to power both.
- Plug in a corded phone. Keep 1 corded phone plugged into the hub's phone socket. Cordless bases need mains power, corded phones don't.
- Test it. Switch the socket off at the wall. The hub lights should stay on and you should still get a dial tone.
LineKeeper™ Hub Battery Backup
4+ hours of backup · fits in 60 seconds · free UK delivery · 90-day money-back
From £89
Sources and further help
How we write our guides
Written by the LineKeeper team in plain English. We check facts against Ofcom, Openreach and provider guidance, and update guides when the rules change. We sell the LineKeeper Hub Battery Backup, and we say when it isn't the right fit. About us.
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Helpful answers
Frequently asked questions
Straight answers to common questions about mini ups for wifi router.
Can a power bank work as a mini UPS for my router?
Most phone power banks output 5V USB and don't switch over automatically, so they're not a good fit for a 12V hub.
Are mini UPS units safe to leave plugged in?
Good ones are designed for it. Look for UK-compliant products with clear safety information and a real support contact.
Do I need an engineer to fit it?
No. Fitting takes about 60 seconds: move the hub's power lead into LineKeeper and plug LineKeeper into the hub. No app, no settings.
Is there a guarantee?
Yes. Every order has a 90-day money-back guarantee and free tracked UK delivery.
Keep your line on through the next power cut
From £89 (was £178). Free tracked UK delivery, 90-day money-back, fits in 60 seconds.
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