A home battery without solar.
Worth it in 2026?

How it saves money

On a typical smart or EV tariff you might pay around 35p per kWh during the day and around 7.5p overnight. Every kWh the battery stores at night and releases during the day saves you roughly 27p. Fill a 12 kWh battery each night and that is about £1,000 a year, before you add any solar later.

A battery does something timers never can: it shifts the energy, not your lifestyle. Load shifting means delaying jobs until the cheap window opens, but with a battery you can turn the oven on at teatime without checking the clock, because the house runs on electricity bought overnight. How load shifting compares.

What moving with a battery involves

Taking it with you is two separate jobs and they do not have to be the same person. A qualified electrician disconnects it cleanly at the old house, then an electrician at the new one fits it on its own circuit, the same way an EV charger goes in. Move halfway across the country and you will use two different firms, which is completely normal.

Keep the commissioning paperwork with the unit so whoever fits it next knows exactly what they are reconnecting. The new property gets its own checks too. Consumer units vary, so the electrician needs to see it first, and questions about the network notification and whether the warranty follows the battery are worth asking before you move, not after.

What size do you need?

Installers now rarely quote small 5 kWh units. The sweet spot is 10 kWh and above, because the battery should cover your whole evening and morning, not just the lights. As a rough guide: 6 kWh suits a flat, 12 kWh suits a typical family home and 18 to 24 kWh suits busier homes with an EV or electric heating.

My next install at home will be a 12 kWh battery and I will document the whole thing here, from the quote to the first month of bills.

Your smart meter app or a recent bill shows how much you use between the end of the cheap window and bedtime. That number, in kWh, is the size conversation in a nutshell.

Can a home battery charge my EV?

It is the first thing people picture: cheap overnight electricity stored up, then pushed into the car. Think of your home battery as a bucket of water and your car battery as a paddling pool. Tipping the whole bucket in barely covers the bottom, and that is roughly what a 12 kWh home battery does for a car: about 30 to 40 miles of range.

Pouring from one container into another loses a little on the way, so charging the car through the house battery costs more than plugging it straight into the cheap overnight window. The wallbox does that with nothing lost, so leave the car to its own charger and let the home battery do what it does best: quietly powering your kettle, oven and lights through the evening so you never pay peak daytime rates.

More on why the car is king when it comes to charging and choosing a charger that follows your tariff.

What are my options?

The UK market has moved on quickly. These are the names you will hear quoted, and what each is known for:

• Wondrwall: a British system with AI that learns your routine and trades energy automatically. Modular from about 6 to 25 kWh, with a monthly plan option instead of one big upfront cost. Full disclosure: I join Wondrwall in November and this is the battery I will be installing and writing about.
• Tesla Powerwall 3: the best-known name, a single 13.5 kWh unit at the premium end.
• Sigenergy SigenStor: a sleek modular stack that can also DC-charge an EV.
• SolaX: a capable trade favourite that often comes in at the lower end of quotes.

One name you may still see in older articles is GivEnergy, which has gone out of business. Always check a manufacturer is trading before you commit, because the warranty is only as good as the company behind it.

Where can it live?

Most modern batteries are rated for outdoor installation on a wall, which is where many end up. A garage or utility room works too. One place to avoid is the loft: current fire-safety guidance (PAS 63100) steers batteries away from lofts and escape routes. A good installer will walk the options with you.