A portable power station is a large battery in a box with normal three-pin sockets, USB ports and often a car socket, so it can quietly run mains appliances during a power cut without the fumes, noise or fuel of a petrol generator. For most UK households it's the practical middle ground: far more capable than a power bank, but safe to use indoors, unlike a generator. It won't power your whole house, but it will keep the essentials going through a storm outage.
The specs can be confusing because two different numbers both matter. This guide explains watt-hours versus watts, what a power station can realistically run, the battery chemistry worth paying for, and how to size one for your own home rather than the biggest number in the shop.
The two numbers that matter: watt-hours and watts
Capacity is measured in watt-hours (Wh): how much energy the station stores, and therefore how long it lasts. A 500Wh station can, very roughly, run a 50W device for about ten hours, or a 100W device for about five, before it's flat. More watt-hours means longer runtime and a bigger, heavier, pricier unit.
Output is measured in watts (W): how much power it can deliver at once. If an appliance's power draw exceeds the station's rated output, it simply won't run, no matter how big the battery is. A kettle or heater pulling 2000W+ needs a station rated for that; a phone charger pulling 15W will run on almost anything. Always check both numbers: watt-hours for how long, watts for what.
Watch the 'surge' or 'peak' figure too. Some appliances (fridges, pumps) briefly draw far more power at start-up than they use running. A station needs enough surge headroom to cope, or it'll trip out the moment the compressor kicks in.
What can it actually run?
Comfortably, on a mid-sized station: phones, tablets and laptops, LED lighting, a broadband router, a mobile signal booster, a CPAP or other low-draw medical device, a TV, and charging your other batteries. This is the sweet spot — keeping communications, lighting and essential electronics alive through a multi-hour or overnight outage.
Briefly, on a larger station: a fridge or freezer (which cycles on and off, so it draws power only part of the time), a microwave, or a small heater — but these eat capacity fast, so plan for hours, not days. What a portable power station generally cannot do is run high-wattage heating, an electric shower, an oven or an immersion heater; those draw more than portable units are built for. For heating in a power cut, layers, a warm room and safe non-electric options matter more than trying to power a heater from a battery.
Battery chemistry: LiFePO4 vs standard lithium
Most newer, better power stations use LiFePO4 (lithium iron phosphate) cells. They cost a little more but last far longer — often 2000 to 4000+ charge cycles versus a few hundred for older NMC lithium — hold up better in the cold, and are more thermally stable. For something you'll charge, store and rely on for years, LiFePO4 is worth paying for. Cheaper standard-lithium units are fine for occasional use but degrade sooner, especially if left sitting.
Whichever chemistry, store the station around half to three-quarters charged, top it up every few months, and keep it out of extreme cold. A power station that's flat when the storm hits is no use, so treat charging it like testing a smoke alarm — a regular, boring habit.
Ports, recharging and features
Check the outputs match your needs: enough three-pin UK sockets, USB-A and USB-C (ideally USB-C Power Delivery for laptops), and a 12V car socket if you want it. Look at how it recharges — from the mains (how many hours to full?), from a car, and from a solar panel. A station that accepts solar input lets you extend a long outage by topping it up in daylight, which turns a one-day kit into a several-day one.
A clear display showing remaining capacity and current draw is genuinely useful, as is a pure sine wave inverter (kinder to sensitive electronics and medical devices). Consider weight and a handle if you'll move it between rooms or take it camping.
How to size one for your home
List the few things you truly need to keep running in an outage and add up their wattage. For most households that's phones, lights, a router and maybe a medical device — a load easily met by a 300Wh to 600Wh station, which will see you through an evening or overnight. If you also want to keep a fridge-freezer ticking over or ride out longer outages, step up to 1000Wh+ and consider a solar panel to recharge it. Bigger isn't automatically better — buy for the essentials you'll actually run, not a worst-case fantasy.
How to choose in one line
For a typical UK home power-cut kit, buy a 300-600Wh LiFePO4 power station with enough three-pin sockets, USB-C PD and a pure sine wave inverter, and keep it charged. Size up to 1000Wh+ (with solar input) only if you need to run a fridge or ride out multi-day outages, and remember it's for essentials — not heating or your whole house.
