Using a Portable Power Station in a Power Cut: What to Run and What Not to Connect

A portable power station can keep a router, lights and a phone running in a power cut, and it needs no fuel. Work out the load first, plug appliances in directly, and leave any connection to the house wiring to an electrician.

Why people choose one

National Grid's power cut guidance tells people never to use a portable generator or barbecue indoors during a power cut, because fuel-burning appliances can release carbon monoxide, an invisible, odourless gas that can kill (National Grid). A battery-based power station has no combustion and so no exhaust, which is the main reason it suits indoor use. It still has limits: capacity is finite and maximum output is capped. Our guide to camping versus home backup covers when a unit is the right tool.

Work out what it can run

Two figures matter. The first is the unit's usable energy in watt-hours, and the second is its maximum continuous output in watts. Add up the watts of the things you want to run, check the total sits under the maximum, then divide usable watt-hours by the total watts to estimate hours. Real runtime is shorter, because converting power loses energy; the Energy Saving Trust notes energy taken from a battery is less efficient than using power directly (Energy Saving Trust).

As an illustration with made-up round numbers: a 1,000 Wh usable unit feeding a 100 W load in total (router, a lamp and phone chargers) would last well under 10 hours once losses are counted. Add a 1,000 W kettle and the picture changes completely, since heat loads are the fastest drain. Our power stations section lists the capacity and output figures for the models we cover, and Compare For Yourself puts them side by side.

• Good fits: router, lights, phones, laptops, a small TV, medical devices if the maker says the unit is suitable.
• Poor fits: kettles, heaters, ovens, hair dryers and anything else that makes heat.
• Check start-up surges on fridges and pumps against the unit's surge rating.

What not to connect

Plugging a power station into a wall socket or a fuse board to "power the house" is not a safe do-it-yourself job. The IET says a switching arrangement is usually needed to form a separate island supply, and that a system able to switch between connected and island modes usually needs G98 or, more likely, G99 notification (IET). That is installer work, not a lead and an adaptor. Use extension leads from the unit to the few devices you need, and keep leads untangled and out of walkways.

If you want some circuits to stay live automatically, that is a different product: a fixed battery with a backup circuit. See home batteries for emergency power.

Prepare before the outage

Keep the unit charged and check it every few months, since stored batteries drift down. Know where the manual is, what the maximum output is and which of your devices matter most. Put a list of essentials on the unit. A short test at home, running only the planned items for an hour, shows how much charge they really use.

Common questions

Related guides

Keep reading, or check your own numbers:

• Camping versus home backup
• Home batteries for emergency power
• Power stations
• Winter storm readiness