Portable power stations: is one worth it, and what size do you need for a UK power cut?

Do you need one at all?

Start with what you must keep running, not with the box. Be Ready's power-cut advice is a torch, a battery or wind-up radio and charged devices. For most homes, that means power banks, not a power station. See how to keep your phone charged.

A power station (a big rechargeable battery with USB, 12 V and normal three-pin sockets) is worth looking at if:

• someone uses a CPAP or other powered medical device at home;
• you need the broadband router for work, or to stay in touch;
• you live in a flat, where a petrol generator isn't safe or practical;
• you want light and charging for several days, not one evening.

Citizens Advice says to check the battery of any medical or accessibility equipment now, and how long it lasts. If someone relies on powered equipment, join the Priority Services Register with your energy company (Ofgem): it's extra help in a power cut, including advance notice of planned cuts where possible.

Watts and watt-hours, in plain words

• Watts (W): how fast something uses power.
• Watt-hours (Wh): how much it uses over time. A 10 W router for 5 hours uses 50 Wh.
• Power stations are sold by Wh. That's the number to compare.

Your daily power budget

Fill in your own. The figures below are typical, not measured on your kit: use the label, the manual or a plug-in power meter while the mains is on.

Then (our calculation, a common rule of thumb):

1. Add about 15% if you'll use the three-pin socket, because the inverter wastes some power.
2. Add about 20% as a margin.
3. Multiply by the number of days you want.

So 200 Wh a day becomes about 270 Wh a day, and about 800 Wh for 3 days.

What the common sizes really run

Our calculations from the budget above, with no recharging:

For example, Jackery lists its Explorer 300D at 288 Wh and its Explorer 1000 Plus v2 at 1,024 Wh, both with LFP batteries. Every brand publishes the same kind of figures; compare the Wh, not the name.

The fridge question

UK forums ask this a lot. Our estimate from EU energy labels is that a fridge-freezer uses roughly 0.4–0.8 kWh a day (divide the kWh-per-year on its label by 365). That's most of a 1,000 Wh station in one day.

The Food Standards Agency's advice is usually the better plan: keep the doors shut. A fridge should stay cold for up to 4 hours and a full freezer frozen for up to 48 hours (24 if half full). Use our fridge and freezer timer to track it.

What to check before you buy

• Capacity in Wh. Size it from your budget, not the photo.
• Battery type and cycles. Many makers now use LiFePO4 (also called LFP) batteries and rate them for thousands of charges: Jackery lists up to 4,000 cycles for the 300D and 6,000 cycles to 70% capacity for the 1000 Plus v2. Check the maker's own figure.
• Continuous output in watts. It must be higher than the device you plug in. Heaters, kettles and hobs draw 1,000–3,000 W and will empty a station fast.
• Ways to recharge. Mains, the car's 12 V socket, and a solar input. A folding solar panel gives far less in a UK winter than its label says.
• Weight. A 1,000 Wh unit is heavy. Can you carry it up the stairs?
• Pass-through charging, so it can act as a back-up while plugged in.

Safety

• A battery power station makes no fumes, so it can be used indoors. A petrol generator never can: the NHS warns fuel-burning appliances can cause carbon monoxide poisoning, which can kill.
• Follow the maker's charging instructions, keep it on a hard, dry surface, and away from heaters and curtains. The Scottish Fire and Rescue Service's power-cut advice is to keep heat sources away from furniture and curtains.
• Boilers: Citizens Advice says most gas boilers need electricity. Don't cut into boiler wiring to run it from a power station. Ask a qualified electrician and a Gas Safe engineer first.

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Related guides

• Do you need a portable power station for power cuts?
• Power cut kit: what to keep in one box, and how long power cuts last
• Medicines that need a fridge: what to do in a power cut
• Fridge and freezer in a power cut: how long is food safe?
• Priority Services Register: a plain guide

Free tools

• Power station runtime calculator
• Fridge and freezer power cut timer
• Priority Services Register checker

We're an independent UK site, not the government. We check guides against official sources and link to them. In an emergency call 999.

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