Can I have a home battery without solar panels?

Yes. A home battery doesn't need solar panels. It can charge from the grid when electricity is cheapest, usually overnight, and power your home at busier, pricier times of day. Set up the right way, it can also keep your lights and fridge running during a power cut. Whether it's worth it depends mostly on your electricity tariff and how you use power through the day.

This post explains how a battery works without panels, the two main reasons people fit one, what affects whether it pays its way, and what installation involves. Batteries store a lot of energy, so fitting and connecting one is a job for a qualified electrician, not a DIY project.

How a battery works without solar panels

With solar, a battery stores the spare electricity your panels make in the day. Without panels, it fills up from the grid instead.

The battery connects to your home's wiring through an inverter, a box that turns the battery's direct current (DC) into the alternating current (AC) your sockets and lights use, and back again for charging. A controller, usually set through a phone app, decides when the battery charges and when it powers the house. Day to day, you don't notice it: your appliances simply draw from the battery when it has charge and from the grid when it doesn't.

Reason one: using cheap overnight electricity

Some electricity tariffs, often called time-of-use tariffs, charge much less for electricity at night than during the day. A battery lets you buy cheap electricity overnight, store it and use it in the evening, when prices are highest and most households use the most power.

This works best if:

• you're on, or can switch to, a tariff with a big gap between the night and day price

• most of your electricity use is in the morning and evening rather than overnight

• you have a fairly steady pattern of use, so the battery can be set to match it

It works less well if your tariff charges the same price all day, as there's no cheap period to store.

Winter is when a battery like this earns most of its keep. Evenings are long, lights and appliances are on for longer, and solar panels, if you added them later, make the least power.

Reason two: keeping the power on in a power cut

Many people assume any home battery will keep the house running during a power cut. Most won't. A standard battery switches off when the grid goes down, for safety, so it can't send electricity back into cables that engineers may be working on.

To keep power on, the system has to be designed for backup, with a changeover switch that cuts your home off from the grid and runs it from the battery instead.

We fitted exactly this for a home in a West Sussex village that had frequent power cuts. The family were worried about an elderly relative who found the cuts stressful. We installed a 5.4kWh battery with a 5kW inverter and an automatic changeover switch, which moves the house onto battery power in under half a second, quickly enough that the internet doesn't drop. The oven and tumble dryer went onto a separate circuit that isn't backed up, as they'd drain the battery quickly. The rest of the house can run for 6 to 10 hours, much longer than the local cuts usually last. You can read more in our post on this battery back-up job.

What affects whether it's worth it

A battery is a long-term purchase, so it's worth looking at:

• The price gap. The bigger the difference between your night and day rates, the more each charge saves.

• How much you use at peak times. A battery sized to your evening use saves more than one that sits half empty.

• Energy lost in storage. Some energy is lost every time a battery charges and discharges, so you get back a little less than you store.

• The warranty. Battery warranties usually cover a number of years and a minimum remaining capacity. Check what's included.

• VAT. Since February 2024, battery storage installed on its own has qualified for the 0% VAT rate for energy-saving materials, as it already did when fitted with solar panels.

Adding solar panels later

If you think you might add solar panels in future, mention it at the start. Some batteries and inverters make adding panels later simple, others need extra equipment. Choosing well now can save cost and disruption later. Our guide to how solar PV and battery storage work together explains how the two systems share the job.

What installation involves

A battery is usually fitted in a garage, utility room or on a suitable wall, away from damp and following the manufacturer's instructions on where it can and can't go. It connects to your consumer unit, the box with your fuses or circuit breakers, which may need changes or an upgrade. The local electricity network operator also has to be told about any battery that can send power to the grid, and larger systems need their approval before they're connected.

How we plan a battery installation

We're NAPIT registered electricians and MCS certified installers, and the same in-house team handles the survey, installation and handover. We'll look at how and when you use electricity, check where the battery and inverter can safely go, and set out in a written proposal whether a battery is likely to benefit your home, including setting it to top up overnight when rates are lower.

If you're wondering whether a home battery would suit you, with or without solar panels, Resistance Electrical can talk you through the options. Find out more on our solar PV and battery storage page.