Batteries

Will an EcoFlow OCEAN 2 keep my lights on in a power cut?

Yes, if it is installed with backup. A 5 kWh OCEAN 2 runs lights, fridge, router, boiler controls and a TV for a full evening; a 10 kWh system runs them overnight. It will not run an electric shower or a hob for long. Here is what to expect.

By Samantha Warry5 October 20265 min read

The short answer: yes, if it is installed with backup wiring. A 5 kWh EcoFlow OCEAN 2 will run your lights, fridge, freezer, router, phone chargers, boiler controls and a television for a full evening. A 10 kWh system runs them through the night. It will not run an electric shower, a tumble dryer or an induction hob for long, and it should not be asked to.

Why backup has to be asked for

A standard solar system shuts down the moment the grid goes off. That is deliberate: it stops your roof pushing electricity down a line an engineer from the network is trying to repair. To keep the house running, the battery system has to disconnect the house from the grid first, then power it from the battery. The OCEAN 2 is built to do that, but the circuits it protects have to be chosen and wired at installation. If you want backup, say so at the survey.

What a 5 kWh battery actually runs

Load	Roughly	On a full 5 kWh
LED lighting, whole house	100 W	Two days
Fridge freezer	40 W average	Five days
Router, TV, laptops	150 W	A day and a half
Gas boiler controls and pump	100 W	Two days
Kettle	3,000 W	About 40 boils
Electric shower	8,500 W	Half an hour. Do not.

Typical UK figures, rounded. Running all of the essentials together, a household uses roughly 300 to 500 W in the evening, which a 5 kWh battery covers for ten hours or more.

Where power cuts actually happen round here

The rural edges of the service area, the villages between Wimborne and Blandford, the New Forest side of Ringwood and Lymington, and the long lines out to Dorchester and Weymouth, see more outages than Bournemouth or Poole, usually in winter storms. If you are on an overhead supply, backup is worth a serious look. If you are on a modern underground estate, it is a nice-to-have.

Attribution.Switch-over time, capacity and the 15-year warranty are EcoFlow’s published specifications for the OCEAN 2. The table above uses typical appliance figures, not EcoFlow data.

Get it designed in

Tell us at the free survey that backup matters to you. We design which circuits are protected, size the battery accordingly, and the MCS-certified engineers wire it that way on the day. More on battery storage, or see whether a battery pays for itself first.

Questions people ask about this

Does every battery work in a power cut?

No. Many home batteries, and all grid-tied solar without a battery, shut down in a power cut for the safety of the engineers fixing the line. Backup needs a battery and inverter designed for it, like the OCEAN 2, plus the right wiring at installation. Ask for it specifically.

How quickly does it switch over?

EcoFlow quotes a switch-over in milliseconds for the OCEAN 2, fast enough that most appliances do not notice. Clocks on the oven may not even blink.

Will my solar panels charge the battery during a power cut?

With a backup-configured OCEAN 2, yes, in daylight the panels can keep topping up the battery while the grid is down. A long daytime outage in summer is the best case; a winter evening is the worst.

Can it run the whole house?

It can run the essentials for a long time or heavy loads for a short time. A 5 kWh battery holds about 5 units of electricity. An electric shower uses 8 or 9 units an hour; a fridge uses about 1 a day. We wire the circuits that matter and tell you which ones they are.

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