Battery Storage Directory UK (2026)
Home battery storage lets you keep the energy your panels generate during the day and use it in the evening — or charge overnight on a cheap tariff and avoid peak prices. From plug-in systems to whole-home installations, here's what's available in the UK right now.
Do you need a battery with plug-in solar?
Strictly speaking, no. A plug-in solar system works without a battery — your panels feed power directly into your home, and whatever you generate offsets what you'd otherwise draw from the grid. But without a battery, any power you generate and don't immediately use is wasted (or exported for very little return).
A battery lets you store surplus daytime generation for use in the evening. It also opens up overnight arbitrage — charging on cheap off-peak rates (e.g. Octopus Go at 7.5p/kWh) and discharging during peak hours (30p+/kWh). This alone can save £200–400 a year, even without solar panels.
Plug-in solar batteries
Designed specifically for plug-in and balcony solar setups. These combine a battery and microinverter in one unit — plug in your panels, plug into a socket, done.
EcoFlow STREAM Ultra
The top of EcoFlow's new STREAM range — purpose-built for UK plug-in solar. 1.92 kWh LiFePO4 battery with a built-in microinverter, 4 MPPT channels for up to 2,000W of panel input, and 1,200W AC output. Pairs a second unit for 2,300W and 3.84 kWh. Fanless, IP65 weatherproof, and controlled via the EcoFlow app with smart tariff support. The most feature-rich plug-in battery on the market.
EcoFlow STREAM Max
The mid-range STREAM — same 1.92 kWh LiFePO4 battery but with 2 MPPT channels (1,000W PV input) and 800W AC output. Fanless and IP65. The sweet spot for a two-panel plug-in system where you don't need 4 MPPT inputs. Expandable with extra battery modules.
EcoFlow STREAM AC Pro
The AC-coupled STREAM — designed to work with any existing microinverter, not just EcoFlow's. If you already have a Hoymiles or other microinverter and want to add battery storage, this is the one. 1.92 kWh, 800W output, 2 MPPT channels. Same IP65 build and 10-year warranty.
AFERIY PS240
A strong budget contender. 1.96 kWh base capacity expandable to a massive 9.79 kWh with add-on modules. 800–1,200W output, IP65 weatherproof, and uses premium EVE LiFePO4 cells rated for 6,000+ cycles. Smart app with dynamic tariff support (works with Octopus). 10ms UPS switchover for power cuts. A lot of battery for the price.
Indevolt PowerFlex 2000
European-designed plug-in battery with impressive expandability: start at 2 kWh, scale to 36 kWh across three linked units. 2,400W bidirectional inverter, 4 MPPT channels with 2,400W PV input, and 8,000-cycle LiFePO4 cells — the longest cycle life in this category. Open local API for smart home integration (Shelly, Home Assistant). Works with dynamic tariffs including Octopus.
DJI Power 2000
Yes, that DJI — the drone company. The Power 2000 is a 2,048 Wh portable power station with 3,000W output and LiFePO4 cells. Not designed as a dedicated plug-in solar battery, but it's a versatile unit that doubles as a portable power station, UPS, and solar charger. Charges 0–80% in 55 minutes via mains. Add the MPPT dongle (£49) to connect up to 400W of solar panels via XT60.
Dedicated home batteries
Permanently installed batteries for whole-home energy storage. Higher capacity, longer warranties, and designed to run your entire house — but they require professional installation. Listed here cheap to expensive.
Fogstar Energy 16.1 kWh
The best value per kWh on the market. UK-designed and assembled, with LiFePO4 cells rated for 8,000 cycles at 91% depth of discharge — that's roughly 20 years of daily cycling. Built-in heating system for cold-weather charging (down to -10°C) and integrated fire suppression on the 2026 models. Pairs with a compatible hybrid inverter (GoodWe, Solis, etc). At roughly £121/kWh, nothing else comes close on price.
Sigenergy SigenStor
A modular 5-in-1 system that combines battery, inverter, EV charger, smart energy management, and backup power in one unit. Modular design: choose 6 kWh or 9 kWh battery modules, stack up to six for 54 kWh total. Inverter sizes from 3 kW to 12 kW. Full power-cut protection for single-phase and three-phase supplies. LiFePO4 chemistry with 10-year warranty (extendable to 15). The most feature-complete mid-range system on the UK market.
Tesla Powerwall 3
The most recognisable name in home batteries. 13.5 kWh capacity with an integrated 11.5 kW inverter — no separate inverter needed. LiFePO4 chemistry (upgraded from NMC in the Powerwall 2). Features storm watch, time-of-use optimisation, and full home backup via the Tesla Gateway. Expandable to 54 kWh. Expensive, but the app, brand support, and resale value are unmatched. 10-year warranty guaranteeing 80% capacity.
Quick comparison — plug-in batteries
| Battery | Capacity | Output | MPPT | Cycles | Price |
|---|---|---|---|---|---|
| EcoFlow STREAM Ultra | 1.92 kWh | 1,200W | 4 | 6,000 | £1,199 |
| EcoFlow STREAM Max | 1.92 kWh | 800W | 2 | 6,000 | £879 |
| EcoFlow STREAM AC Pro | 1.92 kWh | 800W | 2 | 6,000 | £899 |
| DJI Power 2000 | 2.05 kWh | 3,000W | MPPT dongle | 4,000 | £1,099 |
| AFERIY PS240 | 1.96–9.79 kWh | 800–1,200W | — | 6,000+ | £799 |
| Indevolt PowerFlex 2000 | 2–36 kWh | 2,400W | 4 | 8,000 | ~£680 |
Quick comparison — dedicated home batteries
| Battery | Capacity | Chemistry | Inverter | Warranty | Price |
|---|---|---|---|---|---|
| Fogstar Energy 16.1 kWh | 16.1 kWh | LiFePO4 | Separate (compatible) | 6 yr + 10 yr support | £1,950 |
| Sigenergy SigenStor | 6–54 kWh | LiFePO4 | Built-in (3–12 kW) | 10 yr (ext. 15 yr) | from £9,600 |
| Tesla Powerwall 3 | 13.5 kWh | LiFePO4 | Built-in (11.5 kW) | 10 yr | £8,500–10,000 |
Tip: If you're on a time-of-use tariff like Octopus Go, even a modest battery can pay for itself through overnight arbitrage alone. See our blog for a full guide to overnight charging strategies.
Frequently asked questions
Is home battery storage worth it without solar panels?
Yes — if you're on a time-of-use electricity tariff. You charge the battery overnight at off-peak rates (as low as 7.5p/kWh on Octopus Go) and use stored energy during peak hours (30p+/kWh). A 2 kWh battery doing this daily can save £200–300 per year. Larger systems like the Fogstar 16.1 kWh can save considerably more.
EcoFlow STREAM vs DJI Power 2000 — which is better for plug-in solar?
The EcoFlow STREAM is purpose-built for plug-in solar — it has built-in MPPT channels, smart tariff control, and integrates seamlessly with panels. The DJI Power 2000 is a more versatile portable power station that can do solar (via the MPPT dongle), but it's not specifically designed for grid-tied plug-in setups. Choose the STREAM if plug-in solar is your primary use case; choose the DJI if you also want a portable power station for camping, emergencies, or drone charging.
What is the DJI Power MPPT dongle?
The DJI Power Solar Panel Adapter Module (£49) adds an MPPT charge controller to the DJI Power 2000. It connects via XT60 and supports up to 400W of solar panel input across three panels. Without this dongle, the Power 2000 can't charge from solar panels — it's mains-only.
Fogstar vs Tesla vs Sigenergy — how do I choose?
Fogstar is the budget king — at ~£121/kWh it's the cheapest quality LiFePO4 storage in the UK, but you need a separate hybrid inverter. Sigenergy SigenStor is the mid-range all-in-one with inverter, EV charger, and backup power built in. Tesla Powerwall 3 is the premium option with the best app, brand recognition, and resale value impact. All three use LiFePO4 and have excellent warranties.
Can I add a battery to an existing plug-in solar system?
Yes. The EcoFlow STREAM AC Pro is specifically designed for this — it's AC-coupled and works with any existing microinverter (EcoFlow, Hoymiles, Bosswerk, etc). The Indevolt PowerFlex 2000 also claims 99% microinverter compatibility. If you're already in the EcoFlow ecosystem, the STREAM Ultra or Max connect directly to EcoFlow panels.
What's the difference between LiFePO4 and NMC batteries?
LiFePO4 (lithium iron phosphate) batteries last longer — typically 4,000–8,000 cycles vs. 800–1,500 for NMC (nickel manganese cobalt). They're also safer and more thermally stable. The trade-off is lower energy density, meaning they're physically larger for the same capacity. In 2026, virtually every new home battery uses LiFePO4 — NMC is being phased out.
How long does a home battery last?
Most home batteries are warranted for 10 years. In practice, a LiFePO4 battery charged once daily should maintain 80%+ capacity for 10–15 years. The Indevolt PowerFlex 2000 claims 8,000 cycles (roughly 20 years), while the Fogstar range is rated for 8,000 cycles at 91% depth of discharge. Actual longevity depends on cycling depth, temperature, and usage patterns.