EcoFlow STREAM 5000 vs Anker Solarbank 4 Pro, and the rest of both ranges

EcoFlow and Anker SOLIX are the two names most people compare when they start looking at a solar battery, and in the UK today that comparison comes down to one pair: the EcoFlow STREAM 5000 at £1,699 and the Anker SOLIX Solarbank 4 E5000 Pro at £1,699, direct from each maker's UK store on 10 October 2026. Anker UK sells no other Solarbank. EcoFlow sells six more STREAM models below the 5000, and we cover those further down.

We've reviewed each 5 kWh unit on its own, in our STREAM 5000 review and our Solarbank 4 Pro review. This page is for the person who has narrowed it down to the two brands and wants to know what separates them.

STREAM 5000 vs Solarbank 4 Pro: specs side by side

Prices in this table are re-read from each maker's store every day; the rest comes from the two UK product pages, read on 21 September 2026. Where the makers publish the same figure, that's because the products are that close.

One gap on EcoFlow's side: its UK page doesn't name the battery chemistry. EcoFlow's own Amazon listing calls it an LFP battery, the same chemistry as the LiFePO4 battery Anker states. Anker's warranty line needs a second look too. Its spec table reads “15 Years; 10 Years” under “Product Lifespan and Warranty”, and the highlights say “15-year lifespan”, so we read it as a 10-year warranty. Ask for the warranty document from either brand before you spend this much.

Both are also sold on Amazon UK by the brand itself, through the EcoFlow store on Amazon and the Anker store on Amazon. On launch day Amazon had both at full list price; a day later it had cut the Solarbank 4 Pro well below its list. Which of the two is cheaper changes, so open the Amazon listing and the maker's store side by side before you pay. EcoFlow has already cut the STREAM 5000's list price once since pre-orders opened, from £1,899 to £1,799.

Output, charging and backup power

This is the clearest difference between them. The STREAM 5000 can push 3,000 W into the house and charge from the grid at 3,000 W. The Solarbank 4 Pro does 2,500 W both ways. A UK kettle on its own can draw close to 3,000 W, so that extra 500 W decides whether the battery covers it or the grid tops it up. Anker says its 2,500 W fills the battery from empty in under two hours, which is quick enough for any overnight cheap-rate window.

Both ship throttled. Anker sets the Solarbank 4 Pro to 800 W, and to raise it you email Anker proof of installation from your electrician, after which it sends an unlock password for the full 2,500 W. EcoFlow says the STREAM 5000 starts in a plug-and-play mode limited to the local cap, with anything above that needing a registered electrician's assessment first. That 800W setting comes from the 800-watt limit on plug-in systems in Germany and much of Europe. It doesn't make either unit a plug-in device here.

On backup, neither is a whole-house system. Each has a separate outlet that stays live in a power cut, and only what's connected to that outlet keeps running. Anker rates its at 2,500 W with a 10 ms switchover, which it describes as a UPS function. EcoFlow rates its at 3,000 W and says it switches “immediately”, without publishing a time.

Expansion: 30 kWh or 90 kWh

EcoFlow wins the headline. One STREAM 5000 takes two Expansion Battery 5000 packs for 15 kWh, and its STREAM Gateway links six units into a 90 kWh, 18,000 W system. Anker stops at five BP5000 packs and 30 kWh on a single 2,500 W inverter. Extra batteries cost extra on both: Anker's BP5000 is £1,299 direct, and EcoFlow sells its Expansion Battery 5000 separately too.

For most UK homes that's academic. Ofgem's typical household uses 2,700 kWh of electricity a year, about 7.4 kWh a day, so 5 or 10 kWh of storage is the likely range. Bear in mind that an 18,000 W EcoFlow system is far beyond a G98 notification and would need a G99 application to your network operator before it was installed.

Installing either one in the UK

The plug-in solar route created by SI 2026 No. 848 excludes any device that stores electricity, and the Interim Product Specification it points to bans battery storage within the device. That takes every STREAM battery and every Solarbank off the plug-in route, whatever output they're set to. Both makers say so on their UK pages. EcoFlow: “In the UK, local regulations require the EcoFlow STREAM DIY Cable to be wired into the distribution board, which must be done by a certified installer or electrician.” Anker: the Solarbank 4 Pro “must be hardwired and installed by a qualified electrician”, on a dedicated circuit, by someone Part P-registered. Our battery rules report sets out the wording.

Anker is the more thorough of the two on UK paperwork. Its page says the Solarbank 4 Pro must be installed with Anker's Smart Meter Gen 2, that your electrician notifies the network operator under G98 within 28 days, and it publishes the ENA type test reference, ANKER/19908/V1. It also says the unit is floor-standing only and can't be wall mounted.

EcoFlow's UK page says less. We searched the STREAM 5000 page text for G98, the ENA register and the word DNO and found none of them, and no type test reference. Jonathan Tracey hit the same gap with a pre-production unit, saying in his video that the G98 paperwork was a challenge because the unit wasn't in the ENA database yet. At 3,000 W the unit is inside the G98 limit, so the process should be the same as Anker's. Ask EcoFlow for the type test reference before you order, because your installer will want it for the notification. Our G98 notification guide explains who your operator is and what they need.

Whichever you choose, get the electrician's quote first. It depends on your consumer unit, the cable run and whether you want the backup outlet wired to anything, and it can easily be bigger than the gap between the two sticker prices.

Apps, tariffs and Home Assistant

A 5 kWh battery earns its keep on a time-of-use tariff, filling up when electricity is cheap and running the house when it's dear, so the software matters as much as the hardware. Both rely on a clamp on the meter tails to see what the house is drawing, and when we checked both makers were including one at the sale price: EcoFlow's bundle listed a Smart Meter Dual CT, and Anker's page listed the Smart Meter Gen 2 (£89 on its own) in the box as a free gift.

Anker offers a time-of-use mode and a dynamic tariff mode that follows day-ahead prices, and says it's compatible with Octopus and more than 870 electricity suppliers. It supports two charge and discharge cycles a day, one from cheap overnight power and one from solar. Home Assistant is listed as supported today, and Jonathan Tracey walks through the official integration in his Solarbank 4 Pro review.

EcoFlow's equivalent is OASIS 3.0, run from the EcoFlow app, with schedules built around tariff rates, solar input and weather forecasts. Its page says Home Assistant isn't supported yet, though it's planned. EcoFlow does have a Local Mode that keeps everything on your home network, but its own footnote says dynamic tariff integration, solar forecasting and firmware updates all stop working in that mode, so you'd be trading the clever features for privacy.

The savings claims: £770 and £1,506

Both makers put a big annual saving on the page, and both come from their own modelling. Anker's “up to £770” is £769.82 in the footnote: £423.80 from using your own solar at 26p per kWh, plus £346.02 from charging overnight at 8.5p on a tariff like Octopus Go and discharging at 29.37p. It assumes a £2,510 setup with four 500 W panels, a household using 4,100 kWh a year, and one full cycle every day. Anker's footnote says installation costs aren't included in its 3.3 year payback.

EcoFlow's “£1,506 per year” is further from a single STREAM 5000. Its footnote values every self-consumed unit at 30p per kWh, which is above the 26.32p Ofgem cap rate from October 2026, and the worked example it gives is a household using 7,000 kWh a year with two main units, two expansion batteries and 8,000 W of panels.

Neither figure is wrong as arithmetic, and neither is a forecast for your house. The savings calculator will model the solar half for your own postcode; the tariff half depends on rates only your supplier can give you.

Hands-on evidence from UK reviewers

We haven't had either unit in our hands, so these are the videos we'd watch before spending this much. Review units are often supplied by the maker: eFIXX, Nicolas Raimo and Jonathan Tracey each say so on camera, as does UpsideDownFork in his Anker video.

EcoFlow STREAM 5000: tested on a meter

UpsideDownFork tested the STREAM AC 5000, the version without solar inputs, with a plug-in energy meter. Running off-grid it boiled a kettle at about 2.37 kW without complaint. Charging from empty at 2 kW took about three hours and 5.9 kWh, and it gave back 4.92 kWh at an 800 W discharge, which he works out as 83.3% round trip. At a gentler 300 W discharge it returned 4.48 kWh, about 76%, because an inverter is less efficient well below its rating. Standby draw settled at around 11 W, and a quiet internal fan was audible in a silent room. So if the battery spends the day trickling a few hundred watts into the house, expect nearer 4.5 kWh of the rated 5 back. Those are one reviewer's measurements of one unit.

Anker Solarbank 4 Pro: a real UK installation

eFIXX, a channel made for electricians, fitted one of the first UK units in a retired electrician's garage on a dedicated circuit. The 60 V limit on each MPPT input meant one 440 W panel per input, so four panels needed four cable runs from the roof. Mounting the panels was the hardest part of the job, and the ballasted mounting system cost more than the panels did. The smart meter sits by the consumer unit and talks to the battery wirelessly, so you need Wi-Fi where the battery lives. The 60 V point applies to the STREAM 5000 as well: to get beyond four panels on either, you parallel them with adapter cables.

More worth watching

• EcoFlow Stream AC 5000: UK Rules & Setup Guide, Nicolas Raimo. The clearest explanation of the difference between the STREAM 5000 and the AC 5000, and of why either one goes on its own circuit with a G98 notification in the UK rather than into a socket.
• Anker Solix Solar Bank 4 Pro: The 5kWh Plug-in ready Battery you've Been Waiting For?, UpsideDownFork. Part one of three: unboxing, ports and the smart meter. His unit arrived with a three-pin lead as well as the hardwire connector, and he says plainly that in the UK it has to be hardwired today.
• Anker SOLIX Solarbank 4 Pro: Is This the BEST Plug-In Ready Battery Yet?, Jonathan Tracey. A 28-minute review, including the G98 notification and a walk through Anker's official Home Assistant integration over Modbus TCP.
• EcoFlow AC 5000 Review | UK First Look at the New 5kWh Home Battery, Jonathan Tracey. A first look at a pre-production AC 5000. He mentions that the G98 paperwork was a challenge at that point because the unit wasn't in the ENA database yet.
• Anker SOLIX Solarbank 4 E5000 Pro | Installation Guide (UK Version), Anker SOLIX Guides. Anker's own 11-minute guide: wall brackets, stacking expansion batteries, wiring 4, 8 or 12 panels, and the hardwire connector. Worth sending to your electrician.

What else each brand sells in the UK

Until this summer this comparison meant the first-generation STREAM against Anker's Solarbank 2 Pro. Anker UK no longer lists the Solarbank 2 or the Solarbank 3, so below 5 kWh it's EcoFlow on its own. EcoFlow's UK store carries two generations: the first-generation STREAM units, batteries of 1.92 or 3.84 kWh with 1,000 W to 2,000 W of PV input, and the second-generation STREAM 5000 and AC 5000. Two of the older products, the STREAM Microinverter and the STREAM AC Pro, returned a 404 on their own product pages when we checked, but both are still sold by the maker on Amazon UK. The AC output figures are the maker's maximums; the 800 VA cap on the socket route doesn't apply to a hardwired install.

When we listed every product on Anker's UK store, the Solarbank 4 E5000 Pro was the only battery, alongside its expansion pack, smart meter, cables and mounts. The Solarbank 2 E1600 Pro, the Solarbank 2 Plus and the Solarbank 3 E2700 Pro are all on Anker's German store; on the UK store their pages return a 404, and Amazon UK had no listing for any of them.

Balcony scale: STREAM Ultra X and Ultra vs nothing from Anker

This is the tier the old STREAM-versus-Solarbank argument was about, and in the UK Anker has left it. If you already own a Solarbank 2 Pro it still works, and it was always a conventional install here; our Solarbank 2 Pro page covers it. But you can't buy one new from Anker in the UK today, and Anker's UK pages give no date for the Solarbank 3.

So EcoFlow wins this tier by default, and the model to look at is the STREAM Ultra X: 3.84 kWh, four MPPT inputs taking 2,000 W of panels, 1,200 W of output, 6,000 cycles to 70% capacity, IP65, 38.8 kg, and a 10-year warranty, at £1,259 direct or on Amazon. The STREAM Ultra is the same box with half the battery at £799, and the STREAM Pro drops to three inputs and 1,500 W of solar at £799. Our guide to every STREAM model goes through the differences.

The best evidence of what one of these does in a British garden is Jonathan Tracey's year with a STREAM Ultra and an AC Pro, four 440 W panels hung vertically on a fence, half facing the morning sun and half the evening. After 365 days his dashboard showed £335.13 saved, split between solar power and charging overnight on a cheap rate, against about £2,100 for the whole system, which he puts at a five to six year payback. He calls that the minimum, because vertical panels are close to the worst orientation you can choose. The units were supplied by EcoFlow, which he says on camera; in a year he had one Wi-Fi drop-out and no other faults, and the units have no fans.

Plug-in only: STREAM Microinverter vs no Anker device

Strip the battery out and EcoFlow still has a product and Anker doesn't. The STREAM Microinverter is an 800 W unit with two panel inputs, sold on Amazon UK alone or with two 500 W panels. Because it has no battery it is the one STREAM product that can use the socket route, and since 22 September it has been verified as part of two EcoFlow kits (ECOFL/21128/V1/A3 and ECOFL/21606/V1/A1). Buy it as one of those kits, with the model on the listing matching the register, and you can plug it in yourself. Anker has nothing equivalent on the register. Our certification tracker lists the 120 verified kits.

Dork off-grid's video is a first-hand owner's account of that route with the brand's earlier PowerStream microinverter, bought with his own money. He had an electrician wire it into a circuit breaker, found the 800 W cap wasted the top of his 1,000 W of panels, learnt that without a battery any surplus is lost, and ended up buying the maker's energy meter, £100 plus £90 to fit, and then a STREAM Max battery. His cheap system passed £1,000. Read it as a warning about matching a microinverter to what your home draws in daylight, which applies to any brand.

Which should you buy?

• The STREAM 5000 if you want the higher 3,000 W output and charging, you might expand past 30 kWh one day, and you can wait for EcoFlow's dispatch date. It's also a little lighter, at 45.4 kg against 50 kg.
• The Solarbank 4 Pro if you want it fitted this month, you use Home Assistant, or you'd rather hand your electrician a product whose UK paperwork is already published. It also has the better weather rating, IP66 against IP65.
• A 2 to 4 kWh battery for a flat or a small house: EcoFlow, because Anker has nothing at this size in the UK. The 3.84 kWh Ultra X at £1,259 is the one to look at; the 1.92 kWh Ultra at £799 if that will do.
• Renting, or no chance of a hardwired circuit: neither brand's battery. A verified plug-in kit is the only thing you can legally plug in yourself, from about £449.

If you're still torn between the two 5 kWh units, let the price decide on the day. The hardware is close enough that a £200 swing on either side is a fair reason to pick one over the other.

Where to buy and checking the latest price

Every product here is sold by its maker direct and through the maker's own Amazon UK listing, and the cheaper of the two changes. The board at the top of the page carries the makers' prices with the date they were read; open the Amazon listing beside each for its number.