Best home battery storage UK 2026: six systems compared

Quick answer: The best home battery for most UK homes in 2026 is the Tesla Powerwall 3: 13.5kWh, up to 11.04kW of output and about £7,395 to £7,999 installed. The Fox ESS EVO is the value pick, from £5,336 for 10.24kWh through Octopus. GivEnergy is off the list since its maker entered administration in April 2026. Installed batteries carry 0% VAT until 31 March 2027.

We’ve narrowed the field to six batteries UK installers are quoting in September 2026 and checked each maker is still trading. Prices are the latest published figures; every real install is priced after a survey.

The best home batteries in the UK: our picks

• Best overall: Tesla Powerwall 3, for its output and its warranty terms.
• Best value: Fox ESS EVO, a complete 10.24kWh system with a 12-year warranty from £5,336 installed.
• Best for existing solar (AC-coupled): Enphase IQ Battery 5P, with AlphaESS’s SMILE-G3-B5 as the alternative.
• Best with backup: Sigenergy SigenStor, for its claimed 0ms switchover and room to stack capacity.
• Best app: Tesla, with Sigenergy’s mySigen close behind.
• Budget: AlphaESS SMILE G3 and SolaX Triple Power, if the quote includes the inverter.

Home battery storage systems compared

Sources: Tesla’s datasheet and warranty; Heatable on the Powerwall 3, the SigenStor and brand prices; Solar4Good on Sigenergy controllers; Fox ESS UK; Octopus Energy; Enphase UK’s product page and datasheet, and Solar Trade Sales; AlphaESS’s UK brochure and UK warranty; SolaX’s warranty guide and Solar Trade Sales. Octopus’s £5,336 is its 10kWh battery-only starting price, for one Fox EVO or two Enphase units. Heatable’s AlphaESS and SolaX figures are supply prices, so check whether a quote includes the inverter.

Is every brand still trading?

Yes, as of 25 September 2026. Companies House lists FoxESS UK Ltd, Alpha ESS UK Ltd and SolaX Power UK Ltd as active with no insolvency filings. Tesla and Enphase are listed US companies. Sigenergy, founded in 2022, listed on the Hong Kong stock exchange in April 2026, and its UK company, Sigenergy Technology Ltd, is active with no insolvency filings.

GivEnergy isn’t. GivEnergy Ltd entered administration on 9 April 2026 and ceased trading, and the administrator said no further hardware warranties would be honoured, as ESS News reported. Installed batteries keep working, and the app runs on under a separate company, GivEnergy Software Ltd. We wouldn’t buy leftover stock at any discount. Existing owners should read our GivEnergy review.

Best overall: Tesla Powerwall 3

It isn’t the cheapest per kWh. It wins on the combination. Up to 11.04kW from a single unit is enough to run a whole house in a power cut. The warranty keeps 80% of capacity at year ten with unlimited cycles for normal home use, where Sigenergy’s equivalent is 70% with a throughput cap. And at £548 to £593 per kWh installed, it costs roughly what a SigenStor does.

The trade-offs are real. It comes in one size, and extra capacity arrives in 13.5kWh steps. It charges from the grid at 5kW. Backup needs the separate Gateway, and the full ten-year warranty depends on the battery staying online. Our Powerwall 3 review has the price breakdown.

Best value: Fox ESS EVO

The EVO puts a 10.24kWh battery and a 5, 8 or 10kW inverter in one box, with a 12-year warranty, according to Fox ESS UK. Octopus fits it from £5,336 as its 10kWh battery-only option. With 95% of the 10.24kWh usable, that’s about £548 per usable kWh with the inverter and installation included, less than the £593 per kWh Octopus charges for a Powerwall 3.

Emergency power (EPS) comes as standard, per Green Hat Renewables, and Fox sells the EPS-BOX SP gateway for whole-home backup. The catch is expansion. First-generation EVOs grow by adding whole units, and Fox says the battery expansion port arrives with the second generation in autumn 2026. Ask for the warranty’s capacity-retention figure in writing too, because Fox’s product page doesn’t publish one.

Best for existing solar: Enphase IQ Battery 5P

If you already have panels and a working inverter, an AC-coupled battery leaves that system alone. The 5P is the cleanest example: each 5kWh unit carries its own microinverters, delivers 3.2kVA on the UK model, and is covered for 15 years or 6,000 cycles, to more than 60% capacity. With the IQ System Controller it can back up the whole house, per Solar4Good. Our Enphase IQ Battery 5P review covers the detail.

Bought as hardware it’s pricey, at £2,879 a unit or £576 per kWh before labour. Octopus fits two from the same £5,336 as its Fox option, which changes the maths. It makes most sense beside Enphase microinverters. For a different AC-coupled route, AlphaESS makes a 5kW model, the SMILE-G3-B5. The Powerwall 3 can AC-couple to an existing inverter too. And if your panels run through a SolarEdge inverter, the SolarEdge Home Battery carries 10 years with at least 70% capacity and unlimited discharges, per Midsummer Wholesale. Our retrofit guide walks through the options.

Best with backup: Sigenergy SigenStor

Sigenergy specifies a 0ms switchover to backup with its Sigen Gateway, under its own test conditions, according to Heatable’s review. Single-phase controllers run from 3.6kW to 12kW, and modules stack to about 48kWh, so you can size for a long outage instead of an evening. A roughly 13kWh system starts at £6,995 installed. Solar4Good lists an 18kWh system at £6,000 to £7,500, or from £9,600 with power-cut protection.

Two cautions. The company was founded in 2022, so you’re trusting a young firm with a ten-year promise, and its guarantee is 70% capacity or a throughput limit, weaker than Tesla’s. Solar4Good also records a 2025 recall in Australia of single-phase 8kW to 12kW controllers, fixed with replacement hardware. If you want maximum power per unit instead, the Powerwall 3 with its Gateway is the close alternative. Our SigenStor review and our guide to battery backup in a power cut go further.

Which home battery brands have the most useful apps?

A useful app does three jobs: it runs the battery around your tariff without daily fiddling, it protects a reserve for power cuts, and it lets a smart tariff take control if you want that. On those tests, Tesla’s is the best. Its app uses stored energy when variable prices spike, and Storm Watch charges the battery to full when severe weather is forecast.

Sigenergy’s mySigen comes close. Heatable says it combines tariff, weather, solar and consumption data, and rates the software as one of the system’s strongest points. Solar4Good calls Fox’s app functional rather than polished, but Fox lists integrations with Kraken’s smart tariffs and the Axle Energy virtual power plant.

Octopus’s Intelligent Flux, which runs your battery for you, is a good test of openness. Its compatible brands, per Save On Energy Bills (updated 25 September 2026), are GivEnergy, Tesla, SolarEdge, Enphase, AlphaESS, Fox ESS, Sigenergy and Huawei. SolaX isn’t on the list. Our Intelligent Octopus Flux guide explains how the tariff works.

Budget picks: AlphaESS and SolaX

AlphaESS is the surprise. Its UK warranty promises 80% capacity at year ten with unlimited cycles for solar and time-of-use use, which matches Tesla’s headline terms, and Heatable lists the 10.1kWh G3 at £2,550 supply plus £1,400 installation. SolaX guarantees its 5.8kWh battery for 10 years or 17.9MWh of throughput, whichever comes first. At one full cycle a day, 17.9MWh is more than eight years of use. Our budget battery brands review covers this end of the market.

How to size a home battery

Size it to the electricity you use when the panels aren’t producing, not to your roof. Pull your smart meter’s half-hourly data and add up what you use between about 4pm and 8am. That figure, plus a little headroom, is your target usable capacity. Our battery sizing guide has worked examples.

Two more checks. On a time-of-use tariff, make sure the battery can fill inside the cheap window: a Powerwall 3 charges at 5kW, so 13.5kWh takes about 2.7 hours, inside Octopus Go’s five. And labour is broadly fixed, so bigger costs less per kWh. Octopus’s battery-only prices start at £3,947 for 5kWh (£789/kWh) and £5,336 for 10kWh (£534/kWh). But a battery you never empty never earns its capacity back.

AC or DC coupled: which do you need?

A DC-coupled (hybrid) battery takes power straight from the panels through one combined inverter. An AC-coupled battery has its own inverter and sits beside your existing solar inverter, so solar power gets converted one extra time and a little more is lost.

• Fitting solar and a battery together: go DC hybrid, such as the Powerwall 3, SigenStor or Fox EVO.
• Existing solar with a healthy inverter: go AC-coupled (Enphase 5P, AlphaESS B5) or a hybrid that can AC-couple, like the Powerwall 3. Our AC vs DC coupling guide explains the wiring.
• Existing solar with an ageing inverter: replace it with a hybrid inverter and fit the battery at the same time.

Does a home battery pay back at the October–December 2026 price cap?

Only on a time-of-use tariff, cycled most days. Here’s the maths for a battery charged overnight and used in the day, against the October–December 2026 price cap unit rate of 26.32p/kWh.

• Octopus Go’s off-peak rate was 8.21p/kWh before VAT when we checked on 25 September 2026 (8.63p with 5% VAT). VAT comes off domestic electricity from 1 October and the cap rate excludes it, so we use the pre-VAT figure.
• Allow about 10% round-trip losses (Tesla publishes 89% for solar to battery to home). Each stored kWh then costs about 9.1p.
• That saves roughly 17.2p on every kWh that would otherwise cost the cap rate.
• Shift 8kWh a day, every day, and you save about £500 a year. A Fox EVO at £5,336 pays back in about 11 years, inside its 12-year warranty.
• Shift 10kWh a day and you save about £630 a year. A Powerwall 3 at £7,395 pays back in about 12 years, two beyond its warranty.

Treat those as ceilings. Go’s daytime rate ran from about 28p to 31p/kWh before VAT across regions in September, above the cap, so anything the battery doesn’t cover costs more. Rates move too: Octopus can change Go’s prices, so check them before you buy. On a flat tariff with no solar there’s no gap to exploit. Solar improves things in summer: each kWh of surplus you store instead of export is worth the import price minus the export rate you give up, which our SEG rates table tracks. Our own modelled estimate, in the battery storage guide, is savings of up to £192 a year for a 10kWh battery added to solar on the flat-rate price cap, and a payback of around 27 years; a time-of-use tariff shortens that.

Our position: buy a battery if you’ll cycle it daily on a time-of-use tariff, if you have solar surplus to store, or if you want backup. If none of those applies, don’t buy one yet. If you want installed prices for your home, request a free quote: up to three approved installers who cover your area may contact you. No charge, no obligation.

We haven’t tested these batteries: this comparison uses published specifications, prices and warranty terms, checked 25 September 2026.

FAQs

What is the best home battery storage system in the UK?

For most homes, the Tesla Powerwall 3: 13.5kWh, up to 11.04kW and a warranty that keeps 80% at year ten, for about £7,395 to £7,999 installed. On a tighter budget, the Fox ESS EVO gives 10.24kWh and a 12-year warranty from £5,336.

Which home battery brands have the most useful apps?

Tesla’s, for tariff automation and Storm Watch, which charges the battery ahead of severe weather. Sigenergy’s mySigen is close behind. Tesla, Sigenergy, Fox ESS, Enphase, AlphaESS and SolarEdge are on Octopus’s Intelligent Flux compatible list; SolaX isn’t.

What is the best AC-coupled battery in the UK?

The Enphase IQ Battery 5P, which leaves your existing inverter in place and carries a 15-year or 6,000-cycle warranty. AlphaESS’s SMILE-G3-B5 is another AC-coupled option, and the Powerwall 3 can also AC-couple.

How much does home battery storage cost in the UK?

Octopus’s battery-only prices start at £3,947 for 5kWh, £5,336 for 10kWh and £7,999 for a 13.5kWh Powerwall 3, all at 0% VAT. Our installation cost guide breaks down what pushes a quote up.

Should I still buy a GivEnergy battery?

No. GivEnergy Ltd entered administration on 9 April 2026 and its hardware warranties aren’t being honoured. If you already own one, keep using it: the hardware works and the app continues under a separate company.