Buyer's guide · Power
Most power cuts in Britain are short, though storms can cause longer ones. These are the three levels of backup power that actually match that reality — from a pocket bank to a station that runs the fridge.
UK guidance · Last reviewed September 2026
Independently selected for UK households. We may earn a commission if you buy through our links — it never changes what we recommend.
Autumn & winter 2026 update
Named storm season runs from now until the spring, and power cuts cluster in it. Cold weather matters for your choice: lithium cells lose a noticeable chunk of usable capacity below about 5°C, and a bank left in an unheated garage or a car glovebox will deliver far less than its label suggests on the night you need it. Charge everything to full now, keep banks indoors at room temperature, and top them up when the clocks change.
The sensible household default. 20,000mAh holds roughly twice as much as a 10,000mAh bank, so one bank can keep several phones topped up through a long outage without rationing.
Every option below is one we'd genuinely put in a UK household kit — the difference is budget and how long you need it to last.
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The sensible household default. 20,000mAh holds roughly twice as much as a 10,000mAh bank, so one bank can keep several phones topped up through a long outage without rationing.
The cheapest way to stop being one dead phone away from a problem. Slim enough to live in a grab bag permanently, and about the price of a takeaway.
A mains socket in a box. Runs a router, lamps, a CPAP machine or a fridge for hours, recharges in about an hour, and is safe to use indoors — unlike a generator.
Not sure how much you actually need? Score your household in three minutes and see exactly which gaps to close first.
Want the whole kit in one place? The Power Outage Pack bundles these picks with the checklist items most households still miss.
View the Power Outage PackStart with who will be sharing it, rather than the number on the box.
An affordable 10,000mAh bank suits one person with one phone. As a rough guide it gives around two full phone charges. The real figure depends on your phone's battery size, the energy lost in charging, and how you use the phone, as well as the cable and how cold it is. It's small enough to live in a grab bag. If you want to keep one in the car, check the manufacturer's temperature and storage instructions first, as very hot or cold cars can shorten battery life.
A 20,000mAh bank makes more sense when a household is sharing. Roughly speaking, it holds about twice as much, so several phones can be topped up without anyone having to ration.
A mains power station is a different kind of purchase. It's only worth considering if something with a plug needs to keep running, such as powered medical equipment or a router for home working. Most homes won't need one.
Whichever you choose: a bigger bank you forget to charge is less use than a small one that's full. Top it up every few months and store it as the manufacturer recommends — usually indoors, away from cold garages and hot or freezing cars.
Work out how many phones the bank has to serve, then multiply by two full charges each. That number decides capacity far more usefully than a vague 'three-day' claim. One 20,000mAh bank serves a typical family; two 10,000mAh banks kept in different places can serve them better.
USB banks charge phones, tablets, head torches and rechargeable AA kits. Anything with a plug — router, lamp, medical device, fridge — needs a power station with a real mains socket. Most households want the bank first and only add a station if there is a genuine dependency.
Petrol generators produce carbon monoxide and kill people every winter. If you want indoor backup power, it has to be a battery station. Fit a CO alarm near any fuel-burning appliance regardless.
A charged bank in a drawer you can't locate by torchlight is no use. Keep it with your torch, in one known place, and tell everyone in the house where that is.
Reading guides is the easy half. Check your household score first — three minutes, no signup, and it shows you which of these gaps actually apply to you.
For one phone through a day-long outage, 10,000mAh is usually enough — as a rough guide, around two full charges, depending on your phone's battery size and how you use it. For a household of three or four sharing one bank, 20,000mAh is the realistic minimum. If you rely on medical equipment, a router or a fridge, you need a mains-output power station rather than a USB bank.
Top it up every three months and always after you use it. Lithium cells self-discharge slowly, and a bank left flat for a year may not hold charge when you finally need it. Set a recurring calendar reminder on the same day you test your smoke alarms.
For most homes, no — a 20,000mAh bank plus a torch covers most short outages. A power station earns its price if someone in the household depends on powered medical equipment, if you work from home and need the router up, or if you live somewhere with repeated multi-day storm outages.
A 250–300W fridge-freezer will run from a River-class station for several hours because compressors cycle rather than draw continuously. Keeping the door shut matters more: a full freezer holds temperature for around 24 hours unopened, so you often don't need to power it at all.
Solar is a useful top-up in summer but unreliable as your only plan in a British winter. Treat a solar panel as a bonus for multi-day outages, and rely on charging from the mains between events as your primary method.
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