Battery storage
What a home battery costs in the UK
Our six installed packages work out at £309 to £470 per usable kWh, against a UK market of roughly £400 to £900. Across the warranty, the two Hinen B15 packages store power for the least: 8.2p and 8.3p per kWh stored.
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The one number that compares two quotes
Price per usable kWh
Total price alone tells you nothing until you know how much usable capacity you are buying. Divide by the usable figure, not the number on the box, before comparing anything.
Per usable kWh is each installed package price divided by the datasheet usable capacity, arithmetic on our own prices rather than a manufacturer figure. Market band: 2026 UK cost surveys (kilowatts.uk, bookabuilderuk.com), accessed 3 August 2026; small systems sit above it per kWh because the fixed costs below are spread over less capacity. Installed prices are subject to survey.
Per kWh stored, across the warranty
Price per usable kWh ignores how long the battery is covered. Spread the price over everything it can store filling and emptying once a day for its whole manufacturer warranty and the order changes: Hinen's 12-year warranty puts both B15 packages ahead.
Per kWh stored is the installed package price divided by usable kWh, 365 days and the warranty years on the datasheet (Hinen 12, Duracell and Tesla 10). One cycle a day for 12 years is 4.38 MWh per usable kWh, the throughput Hinen's 12-year warranty tier covers. Arithmetic on our own prices, not a manufacturer figure.
Compare
The six packages, side by side
Installed price, price per usable kWh, the warranty and what happens in a power cut, read from the same data as the calculator below.
 Hinen B15One unit13.68 kWh |
 Two Hinen B15Two units27.36 kWh |
 Duracell Dura16One unit14.4 kWh |
 Two Duracell Dura16Two units28.8 kWh |
 Tesla Powerwall 3One unit13.5 kWh |
 Powerwall 3 + ExpansionTwo units27 kWh |
|
|---|---|---|---|---|---|---|
| Installed price | £5,000 | £9,800 | £4,450 | £8,900 | from £6,350 | from £10,850 |
| Per kWh stored | 8.3p | 8.2pLowest | 8.5p | 8.5p | 12.9p | 11.0p |
| Per usable kWh | £365 | £358 | £309 | £309 | £470 | £402 |
| Usable storage | 13.68 kWh | 27.36 kWh | 14.4 kWh | 28.8 kWh | 13.5 kWh | 27 kWh |
| Warranty | 12 years | 12 years | 10 years | 10 years | 10 years | 10 years |
| Backup | Whole-home with the SmartBox gateway | Whole-home with the SmartBox gateway | Discussed on your call | Discussed on your call | Requires a Backup Gateway 2 | Requires a Backup Gateway 2 |
| Sold | With or without solar | With or without solar | With solar | With solar | With or without solar | With or without solar |
| See the B15 | See two B15 | See the Dura16 | See two units | See the Powerwall 3 | See the Expansion |
Per kWh stored is the installed package price divided by everything the battery can store if it fills and empties once a day for its whole manufacturer warranty; per usable kWh is the price divided by the datasheet usable capacity alone. Both are arithmetic on the prices above, not manufacturer figures.
What each package is worth a year
The site's own calculator model on its opening settings: £150 a month on electricity (about 6,839 kWh a year at the 26.32p cap rate, 1 October to 31 December 2026), someone home some of the day, 12p export and charging at 8.5p off-peak, UK average sunshine.
| Package | Set up | Year one | Installed | Simple payback |
|---|---|---|---|---|
Battery only, no solar | £712 | £5,000 | 7.0 years | |
Battery only, no solar | £744 | £9,800 | 13.2 years | |
With 10 LONGi panels (5.30 kWp) | £1,616 | £9,750 | 6.0 years | |
With 10 LONGi panels (5.30 kWp) | £1,631 | £14,200 | 8.7 years | |
Battery only, no solar | £707 | £6,350 | 9.0 years | |
Battery only, no solar | £744 | £10,850 | 14.6 years |
A bigger battery only earns more when there is evening use to fill it: at £150 a month the second unit adds little, and the gap widens with an EV or a heat pump. Move the spend slider in the calculator to see it for your home.
Install day
What is actually inside the price
Battery modules
The cells themselves, priced by usable kWh: the part most people assume is the whole cost.
Power electronics
A hybrid inverter shared with solar, or a separate battery inverter and charger where the battery is retrofitted on the AC side.
Electrical works
Consumer unit changes, isolators, cable runs, current transformer clamps and the physical mounting or plinth.
Labour and commissioning
Survey, design, the install day itself, configuration against your tariff, and MCS certification.
Only the modules scale cleanly with capacity, which is why cost per kWh falls as the battery gets bigger. Fitting a battery alongside new solar allows one hybrid inverter, cheaper and typically 6 to 8% round-trip loss; retrofitting to existing solar usually means an AC-coupled battery with its own inverter, a second box, and typically 8 to 10% round-trip loss, without needing to replace a solar inverter that still works.
| Backup tier | What you get | Effect on price |
|---|---|---|
EPS socket | One socket wired from the inverter's emergency power terminals: phone, router, a lamp. | Smallest addition, sometimes included |
Partial backup | A sub-board of selected critical circuits: fridge, lighting, broadband. | Additional consumer unit work and a second circuit design |
Whole-home backup | A gateway between the meter and the consumer unit that islands the house and switches the whole installation onto battery. | The most expensive option by a clear margin |
Whether backup is worth the line item on your quote is exactly the kind of question a free design call works through against your own outage history and usage.
A battery without solar
A battery on its own charges from cheap off-peak electricity and discharges through the expensive hours; solar makes the case stronger but is not a requirement for every package.
Of our packages, the Hinen B15 (£5,000, with a free backup gateway) and the Tesla Powerwall 3 (from £6,350) do not require solar to be installed alongside them. With no new panels, the Hinen packages are the lowest installed price per usable kWh we offer: £358 for two and £365 for one, against £402 to £470 for the Powerwall 3. The Duracell Dura16 and the two-unit Dura16 package are priced for installation alongside solar, so a solar-free quote on those two is a separate conversation on the design call rather than the package price above.
VAT is zero rated on a standalone battery exactly as it is on one installed with solar, until 31 March 2027. Standalone systems around 5.8 kWh have been quoted from roughly £3,500 to £4,500 elsewhere in the UK market, with typical paybacks landing around 8 to 13 years against 10-year-and-up warranties, depending on how hard the battery is cycled.
Price your own battery
Pick a package and see the installed price and payback for your own usage. No email needed to see the result.
Hinen B15
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Installed prices
The packages, installed
LONGi 530 W panels£1,000 per kWp- Hinen B15£5,000
- Two Hinen B15£9,800
- Duracell Dura16£4,450
- Two Duracell Dura16£8,900
- Tesla Powerwall 3from £6,350
- Powerwall 3 + Expansionfrom £10,850
Every installation is carried out by our teams, who hold:
Battery cost questions, answered
How much does a home battery cost in the UK?
Our installed packages run £309 to £470 per usable kWh: Hinen B15 £5,000 or two for £9,800, Duracell Dura16 £4,450 and two Dura16 £8,900 (both with solar), and Tesla Powerwall 3 from £6,350, with an Expansion unit from £10,850; the Hinen and Powerwall packages are sold with or without solar, and the Hinen packages have the lowest cost per kWh stored, 8.2p and 8.3p. 2026 UK cost surveys put installed batteries at roughly £400 to £900 per kWh, so these sit at or below the lower end of that band.
Is there VAT on home batteries?
Not until 31 March 2027. Battery storage is zero rated for VAT, and since 1 February 2024 that covers standalone batteries with no solar and retrofit batteries added to existing solar, not only new solar-and-battery installations together. The rate reverts to 5% from 1 April 2027.
Why does a small battery cost more per kWh than a big one?
Because only the battery modules scale with capacity: the inverter, the electrical work, the survey, the install day and the paperwork are broadly fixed whatever size goes in. A Tesla Powerwall 3 Expansion unit, adding 13.5 kWh behind an existing Powerwall, has been quoted around £4,700 installed, near £350 per kWh, against £470 per kWh for a first Powerwall 3 that also pays for the inverter and gateway.
Can I get a battery without solar panels?
Yes. The Hinen B15 (£5,000) and the Tesla Powerwall 3 (from £6,350) do not require solar to be installed alongside them, and the Hinen packages are the lower per usable kWh of the two. The Duracell packages are priced for installation alongside solar, so a solar-free quote on those two runs to a separate, unpackaged price on the design call. Standalone batteries elsewhere in the UK market have been quoted from around £3,500 for roughly 5.8 kWh, and VAT is zero rated on them too.
What can a battery actually save each year?
The spread between the off-peak rate and the price cap is what a battery arbitrages: charging at 8.5p per kWh off-peak and displacing the 26.32p capped import rate gives around 16.9p per stored unit after losses. On the calculator's opening settings a Powerwall 3 on its own is worth about £707 a year. A battery cycled hard, most days of the year, earns its keep; one cycled rarely is worth much less. The calculator on this page runs it for your own numbers.
Get my free quote
Takes about two minutes. We call or text within one working day to book your free 30-minute video design call at a time that suits you. We design it around your roof and your numbers, and our MCS-certified, fully insured installation teams install it.