Home battery storage cost in the UK: 2026 prices, by size and by brand

The short version: most UK homeowners pay between roughly £3,000 and £11,500 for a fully installed home battery in 2026, which works out at around £500 to £800 per usable kWh. A 5 kWh system is typically £3,500 to £5,500, a 10 kWh system (the size most homes end up with) is £5,000 to £8,500, and a 13.5 kWh Tesla Powerwall 3 lands around £8,000 to £11,500 installed. Every one of those figures benefits from 0% VAT until 31 March 2027. The rest of this guide explains the numbers behind those ranges, so you can tell a fair quote from an inflated one.

We are an independent quote and comparison service, not an installer. We match homeowners to vetted, MCS-registered installers and compare brands and prices, so the figures below are what the honest end of the UK market actually charges, not a sales sheet from one manufacturer. Our rule is simple: size a battery to what your home can genuinely cycle in a day, and if a battery is not worth it for you, we will say so.

Cost at a glance: fully installed, by size

This is the quick answer. Every price includes supply and installation at 0% VAT, and assumes a mainstream LFP battery with a standard consumer-unit tie-in. It is a starting frame, not a quote, because the real figure depends on your brand choice, whether you want backup, and how much electrical work your board needs.

If you add solar at the same time, budget £10,000 to £16,000 for a full solar-and-battery system, because you are also paying for panels, an inverter and scaffolding. A battery-only retrofit to existing solar is cheaper than any of these, because there is no roof work at all.

2026 price by size, with cost per kWh

Here is the same data normalised the way we think it should be: cost per usable kWh. This is the single most useful column on the page, because it is the only fair way to compare a small quote against a large one. Notice how the per-kWh figure falls as the battery grows, because the labour, certification and electrical work are broadly fixed and spread across more capacity. A bigger battery can look expensive on the total yet be better value per unit of storage.

One thing this table cannot show is whether a quote is quoting usable or nominal kWh. Nominal is the headline number on the spec sheet; usable is what you can actually draw. Modern LFP batteries give roughly 90 to 100% usable, so always insist quotes are stated in usable kWh, or you are comparing different-sized batteries at different prices. Our savings calculator works in usable capacity for the same reason.

2026 price by brand

Brand is where quotes diverge most, and where the biggest new risk sits. The table below gives indicative fully installed prices, the cost per usable kWh, the warranty, and whether the brand offers genuine whole-home backup. Prices move with dealer, region and any promotions, so treat these as market anchors, not fixed quotes. We match you to installers so you can compare the real numbers for your home.

The GivEnergy row is the reason warranty security now belongs in every buying decision. A cheaper battery is no bargain if the manufacturer cannot honour a 10-year warranty. You can read the background on ESS News and Heatable. It is why we factor manufacturer stability into every recommendation, alongside usable capacity, round-trip efficiency and price. For a value-first solar-and-battery setup, Sunsynk and Alpha ESS lead on cost per kWh; for whole-home backup, the Tesla Powerwall 3 remains the flagship; for premium all-in-one, Sigenergy sits at the top.

Retrofit vs new install, and with solar vs without

Three routes cover almost every home, and they have very different economics. Getting this decision right matters more to your payback than which brand you pick.

The cheapest route in absolute pounds is a battery retrofit, because there is no roof work. It is also the highest-value upgrade for the many UK homes (often from the Feed-in Tariff era) that self-consume only 40 to 60% of what they generate. If you have no solar yet, a combined solar-and-battery install is the cheapest way to get both, because scaffolding, inverter and labour are paid for once. A battery without solar can pay back well, but only on a genuine time-of-use tariff with daily cycling, which is why its range is the widest on the page.

Worked payback: three real households

Payback is where most cost guides go quiet, so here are three concrete, illustrative examples. These are composite scenarios built from the price and saving figures above, not named customers, but the arithmetic is exactly how we model a real quote.

1. Retrofit onto existing solar

A 4-bed semi with a 6 kWp array fitted years ago, using about 4,200 kWh a year, self-consuming only around half its solar. They add a 10 kWh battery, AC-coupled, for £5,600 (0% VAT). By lifting self-consumption from ~50% to ~85% and topping up on cheap overnight power on dull days, they save about £560 a year. Payback: ~7.2 years, with any true surplus still earning SEG on top.

2. Battery without solar on a cheap overnight tariff

A mid-terrace with a north-facing roof, no solar, using about 3,600 kWh a year, on Intelligent Octopus Go at ~7p off-peak. They fit a 10 kWh battery for £6,000 (0% VAT), charge overnight and run the house through the 4 to 7pm peak instead of paying 28p or more. Saving: about £520 a year. Payback: ~8.1 years, proving a battery can pay back with no solar at all, on the right tariff.

3. Large battery with backup, EV and heat pump

A detached rural home with a 5 kWp array, an EV and storm-prone power, using about 6,500 kWh a year. They fit a 13.5 kWh Tesla Powerwall 3 for £9,800 (0% VAT) with whole-home backup. Between solar self-consumption and off-peak EV and household charging, they save about £690 a year. Payback: ~9.4 years, with the whole-home backup as a resilience benefit that money alone does not capture.

Notice the pattern: the biggest battery does not give the fastest payback. The retrofit does, because it fixes an existing daily loss cheaply. That is why we size to what a home can cycle, not to the largest system we can sell.

0% VAT: the deadline that changes the maths

Since 1 February 2024, domestic battery storage in Great Britain has attracted 0% VAT, and crucially that includes standalone and retrofit batteries with no solar. This runs until 31 March 2027, after which it reverts to 5%. On a £6,000 job that is £800 to £2,000 that never used to be there, so it is a genuine reason to install before the deadline rather than after. See the government VAT Notice 708/6 for the detail, and our grants and funding page for how it stacks with the Smart Export Guarantee and other support.

Export income: SEG on top of the bill saving

If you have solar, a battery lets you stop spilling surplus at midday for pennies and instead store it or export it into a higher-priced window. Flat Smart Export Guarantee rates sit around 12 to 15p/kWh in 2026 (Octopus Outgoing 12p, Good Energy around 15p), and time-of-use export tariffs can pay up to around 30p/kWh in the peak window with a compatible battery. Treat export as the secondary benefit, though: the main money is the bill saving from self-consumption. Note that Octopus paused new Flux and Intelligent Flux sign-ups in April 2026, so check current availability before you rely on any one export tariff.

Lifespan and degradation: does it pay back before it fades?

A quality LFP battery is warranted for around 6,000 to 10,000 cycles or 10 to 12 years, retaining roughly 70 to 80% of capacity at end of warranty, and fading only about 1.5 to 3% a year. The Tesla Powerwall 3 carries a 10-year, unlimited-cycle warranty. Because a well-sized battery cycles roughly once a day, the warranted cycles comfortably outlast a normal payback. The real risk is not the cells wearing out; it is buying from a manufacturer that may not be around to honour the warranty, which is exactly the GivEnergy lesson above.

Where the money actually goes

On a typical £5,000 retrofit, the split is roughly:

Because labour and certification are broadly fixed, they explain why a small battery costs more per kWh and a larger one costs less. It also explains why the very cheapest quote can be a false economy: if the total drops far below the market, something in the hardware or the warranty has usually been thinned to get there. The right size for your usage, from a stable brand, fitted by an accredited installer, is what actually pays back. Use our savings calculator to sketch your own figure, then request a quote to have it modelled against your real usage and tariff.