What size home battery do I need? (UK guide)

Start with your daily usage

The typical UK home uses around 8–10 kWh of electricity a day. Check your bill or smart meter app for your own figure.

A battery doesn't need to cover your whole day — just the hours when power is expensive, usually from late afternoon until bedtime.

Rough sizing guide

1–2 bedroom flat or small home: 5–6 kWh.

3 bedroom family home: 8–12 kWh.

4+ bedrooms, heat pump or electric car: 14–20 kWh or more.

With solar panels

If you have solar, size the battery to store your typical summer surplus. As a rule of thumb, around 1–1.5 kWh of battery per kWp of solar works well.

With a cheap overnight tariff

On tariffs like Octopus Intelligent Go or Cosy, you charge the battery cheaply overnight and use it during the day. Here a bigger battery pays back faster, because you can move more of your usage to the cheap rate.

Modular batteries

Fox ESS, EP Cube and Hinen batteries are modular, so you can start smaller and add capacity later. Use our Find yours tool for a personal recommendation.