The best solar batteries in the UK in 2026, judged on specifications rather than marketing, are the GivEnergy All in One and Giv-Bat, the Tesla Powerwall 3, Fox ESS EP series, Sigenergy SigenStor, Alpha ESS SMILE G3 and the Enphase IQ Battery 5P. All use lithium iron phosphate cells, usable capacities run from 5kWh to 13.5kWh per unit, warranties from 10 to 15 years, and sourced installed prices sit between about £5,500 and £9,900. Which is best for you comes down to one question: are you fitting new panels, or adding to panels you already have?
- 13.5kWh usable in a single Tesla Powerwall 3 or GivEnergy All in One
- 12 years warranty on GivEnergy batteries, the longest of the big-capacity units here
- 15 years Enphase IQ Battery 5P warranty in the UK, on a smaller 5kWh unit
- About £540 to £730 per usable kWh, installed, for the 13kWh class
- 0% VAT on batteries installed with or added to solar until 31 March 2027
The comparison table
Figures come from each manufacturer's datasheet. Installed prices are indicative ranges published by UK installers or retailers in 2025 and 2026, linked in the sources; where we could not find a sourced installed price we say so rather than guess.
| Battery | Usable capacity | Power | Warranty | Chemistry | Coupling | Indicative installed price |
|---|---|---|---|---|---|---|
| GivEnergy All in One | 13.5kWh | 6kW continuous, 7.2kW peak (10 seconds) | 12 years | LFP | AC | From £7,295 |
| GivEnergy Giv-Bat 9.5 (Gen 3) | 9.5kWh, stackable to 5 units | Set by the GivEnergy inverter | 12 years, unlimited throughput | LFP | DC with a GivEnergy hybrid, or AC | Not published; quoted with inverter |
| Tesla Powerwall 3 | 13.5kWh | Up to 11.04kW discharge (configurable), 5kW charge | 10 years, 80% capacity | LFP | DC (built-in solar inverter); can also AC couple | £7,395 to £9,895 |
| Fox ESS EP11 | About 9.3kWh (10.36kWh nominal, 90% depth of discharge), up to 4 in parallel | Set by the Fox hybrid inverter | 10 years | LFP | DC with Fox H1, KH or H3 hybrid | Not published; kit with 5kW inverter £3,540 supply only |
| Sigenergy SigenStor | 7.8kWh per 8kWh module or 5.2kWh per 5kWh module, up to 6 modules | 4kW per 8kWh module | 10 years; 70% capacity or 23.77MWh throughput (8kWh module) | LFP | DC (integrated hybrid inverter) | About £6,995 for roughly 13kWh |
| Alpha ESS SMILE G3 | 4.8kWh or 9.6kWh modules, stack to 38.4kWh | 3.68kW or 5kW inverters | 10 years | LFP | AC or DC versions | About £5,500 (4.8kWh) to £6,500 (9.6kWh) |
| Enphase IQ Battery 5P | 5kWh per unit | 3.84kW continuous per unit | 15 years or 6,000 cycles (UK) | LFP | AC (built-in microinverters) | Not published; module £2,874 supply only |
What the numbers actually mean
Usable capacity, not headline capacity
Always compare usable kWh. The Fox EP11 is sold as a 10.36kWh battery, but at 90% depth of discharge you can use about 9.3kWh. GivEnergy and Sigenergy quote usable figures at or close to 100%. A typical home that uses 3,500kWh a year gets through about 9.6kWh a day (3,500 divided by 365), and much of that in the evening when panels have stopped producing, which is why 9 to 13.5kWh units are the most common choice with a 4 to 6kW solar array. Our guide on what size solar battery you need works this out for your own usage.
Power decides what the battery can run
Capacity is the size of the tank; power is the width of the tap. A 3.68kW limit covers lights, fridge, TV and cooking on one or two rings, but not an electric shower or a kettle, oven and heat pump all at once. The Powerwall 3 and the GivEnergy All in One can deliver far more, which matters for homes with a heat pump or an EV. Your network operator may cap how much the system can export under G98 or G99 rules, but that limits export, not what the battery can supply to your own home.
Warranty small print
Ten years is the baseline. What differs is the end-of-warranty promise: Tesla guarantees 80% capacity at ten years, Sigenergy 70% or a throughput cap (23.77MWh for the 8kWh module, whichever comes first), and GivEnergy offers 12 years with unlimited throughput on the Giv-Bat 9.5. Enphase gives 15 years or 6,000 cycles in the UK. If you plan to cycle the battery hard on a time-of-use tariff, a throughput cap can end the warranty early, so read that line.
Chemistry
Every battery here uses lithium iron phosphate (LFP). It is cobalt-free, tolerates thousands of cycles and is more thermally stable than the older nickel-based chemistries. Chemistry is no longer a reason to choose one of these over another.
Worked example: cost per usable kWh
Dividing the sourced installed price by usable capacity puts the big units on a level footing:
- GivEnergy All in One: £7,295 divided by 13.5kWh = £540 per kWh
- Sigenergy, about 13kWh: £6,995 divided by 13 = £538 per kWh
- Tesla Powerwall 3: £7,395 to £9,895 divided by 13.5kWh = £548 to £733 per kWh
- Alpha ESS 9.6kWh: £6,000 to £6,500 divided by 9.6kWh = £625 to £677 per kWh
Adding a battery to existing panels with us starts from £3,995 for a 5 to 10kWh unit, and batteries fitted at the same time as new panels cost less again because they share the inverter, scaffold and electrical work. Our solar battery cost guide breaks those prices down.
Worked example: what a battery earns
Take a home with 4.4kW of solar and a 9.5kWh battery, on an import rate close to the October to December 2026 price cap of 26.32p and an export rate of 12p (rates checked September 2026).
- Summer: storing solar. Say the battery stores 6kWh a day of surplus solar for 180 days. That is 1,080kWh you use in the evening instead of exporting at 12p and buying back at 26.32p. Value: 1,080 x (26.32p minus 12p) = 1,080 x 14.32p = £155.
- Winter: charging overnight. On a tariff with a cheap night window, such as Intelligent Octopus Go at 8p from 11:30pm to 5:30am, the battery fills overnight for, say, 150 days. 150 x 9kWh = 1,350kWh, worth 1,350 x (26.32p minus 8p) = 1,350 x 18.32p = £247.
- Losses. Batteries lose some energy on the round trip. Tesla quotes 89% for the Powerwall 3, so knock roughly 10% off the winter figure: about £222.
That is roughly £155 + £222 = £377 a year. On a £3,995 retrofit that is a payback of around 10.6 years, shorter if you use more in the evening or add an EV, longer if you are out all evening in summer. Intelligent Octopus Go needs an electric car, and daytime rates on time-of-use tariffs can sit above the price cap, so run your own numbers through the solar savings calculator before deciding.
Tariff first, battery second: the same battery can be worth £150 a year on a flat tariff or several hundred on a time-of-use tariff. Choose the tariff you will actually use, then choose a battery that the tariff supports. Our guide to the best energy tariffs for solar explains the options.
Which battery would a surveyor suggest for your home?
We fit several of these brands and choose on the survey, not on a stock list. These are the patterns our surveyors follow.
You are fitting new panels and a battery together
A DC hybrid system is usually the efficient choice, because solar charges the battery without an extra conversion. GivEnergy (hybrid inverter plus Giv-Bat), Fox ESS (H1 or KH hybrid plus EP batteries) and Sigenergy are the typical suggestions, with Sigenergy suiting people who want to add modules later. See our solar and battery packages for prices.
You already have panels
An AC coupled battery leaves your existing inverter alone. The GivEnergy All in One suits most retrofits; the Powerwall 3 suits bigger homes that want high power and whole-house backup. If your roof already runs on Enphase microinverters, the IQ Battery 5P keeps everything in one app. Our battery retrofit page covers the process.
Heat pump, EV or high evening use
Look at 13.5kWh or more and at least 5 to 6kW of power: GivEnergy All in One, Powerwall 3, or stacked Sigenergy or Fox modules.
Small home or tight space
A single 5kWh Enphase unit or a 4.8kWh Alpha ESS module is enough for a flat or a one-person home with modest evening use.
You want backup during power cuts
Not every installation provides it by default. Tesla uses a gateway for whole-home backup, Sigenergy needs its Sigen Gateway, and others use a separate emergency power circuit. Ask for backup to be written into the quote if it matters to you.
Honest caveats
- Installed prices vary with your roof, wiring and whether scaffolding is already up. The ranges above come from other installers' published pages and are a guide, not our quote.
- Specifications change as manufacturers release new versions. We checked datasheets in September 2026.
- A battery rarely pays back faster than the panels themselves. If money is tight, panels first and a battery later is a perfectly sound plan.
For how batteries fit into a whole system, read our home battery storage overview.
Sources: Tesla, Powerwall 3 UK datasheet; Powerwall 3 prices and efficiency, Heatable (updated 17 September 2026). GivEnergy, All in One datasheet, Giv-Bat 9.5 datasheet, installed price Heatable. Fox ESS, EP11 datasheet, kit price Plugin Solar. Sigenergy, Heatable SigenStor review. Alpha ESS, Heatable SMILE G3 review. Enphase, UK launch release and UK warranty, module price Plugin Solar. Tariffs (rates checked September 2026): Intelligent Octopus Go, Outgoing Octopus, Ofgem price cap; Intelligent Octopus Flux battery list, Sunsave (1 July 2026). VAT, HMRC notice 708/6.
