Growatt is a Shenzhen manufacturer that sells through distributors and installers rather than direct to homeowners, and its kit undercuts most of the market: a 3.6kW hybrid inverter lists at around £882 to £932 including VAT at UK retailers, against four figures for the equivalent from a European brand. The catch is not the hardware. It is that Growatt's battery warranty runs for 10 years only if the system stays connected to Growatt's monitoring platform, and drops to three years if it does not.
Every figure below was checked on 26 September 2026 against Growatt's own service commitment page, Growatt's UK Warranty Card, the Growatt Battery Warranty Terms and Conditions covering the ARK, AXE and APX ranges (document GR-WT-2406-A-00), the SPH-UP series installation manual, live UK retailer listings, Companies House, HMRC VAT Notice 708/6 and the Energy Networks Association's G98 and G99 guidance. Where Growatt's marketing and Growatt's warranty paperwork disagree, the paperwork is quoted, because that is the part you can hold someone to.
Ask for the model numbers, the warranty term in writing and the same system priced with one alternative inverter. Quotes come from MCS certified installers covering your area.
Get a Quote →Who you would actually be claiming against
The warranty on a Growatt inverter or battery is issued by Shenzhen Growatt New Energy Co., Ltd in China, not by a British company, and your own legal counterparty is the installer or retailer who sold it to you. That distinction matters more on a budget brand than on a premium one, because the whole argument for buying Growatt is price, and price is what gets tested when something fails in year six.
There is a UK-registered company. Growatt New Energy Technology Limited, company number 08660706, was incorporated on 22 August 2013, is listed as active at Unit 1, The Cromwell Centre, Hainault Business Park, Roebuck Road, Ilford IG6 3UG, and files under SIC code 46180, "Agents specialised in the sale of other particular products". Two earlier entities, Growatt UK Limited and Growatt Inverter Limited, were both dissolved on 20 August 2019. So there is a British sales presence, but the battery warranty document names the Shenzhen parent as the warrantor and is expressly governed by EU law.
Growatt's UK Warranty Card adds a restriction worth reading before you buy a bargain unit from a European website: "UK models only provide warranty service for UK and Ireland client." Growatt's global service terms put it more broadly, saying warranty coverage "is contingent upon the alignment of the country of sale, the country of installation, and the country of after-sales service". A grey-import inverter bought cheaply from a continental distributor and fitted in Britain may not be a unit Growatt will service here.
In practice, under the Consumer Rights Act 2015 your claim for a faulty product goes to whoever sold it to you, which is your installer. That is an argument for choosing an installer who will still exist in five years, and for the same reason it is the argument that runs through choosing a solar installer generally.
The range you will actually see on a British quote
Growatt sells five residential families in the UK, and a domestic quote will normally name one inverter from the first three and, if there is storage, one battery from the fourth.
- MIC (750W to 3,300W, single MPPT) and MIN (2,500W to 10,000W, two or three MPPTs): plain string inverters for solar with no battery. The MIN TL-XH variants are hybrids.
- MOD (3kW to 33kW): three-phase string inverters, which in a domestic setting means larger houses and a three-phase supply.
- SPH: single-phase hybrid inverters that run solar and a battery from one box. The SPH 3000-6000TL BL-UP is the common British domestic unit.
- ARK, AXE and APX batteries: ARK stacks in 2.56kWh modules, AXE in 5kWh low-voltage modules, APX in 5kWh high-voltage modules scaling to 30kWh on one base.
- NEO microinverters and the plug-in NOAH, VETA and AURA units, which sit closer to the balcony and plug-in end of the market than to a fitted roof system.
One number in that range is worth knowing before you read a quote. Growatt's SPH-UP installation manual gives the SPH 3600TL BL-UP a rated input and output power of 3,680W and a rated output apparent power of 3,680VA. That is not a rounding of 3.6kW. The Energy Networks Association writes the same limit two ways: EREC G98 covers fully type tested micro-generators "up to and including 16 A per phase", and it applies to a generator "with a capacity less than 3.68kW/phase", with G99 applying above that. The full picture is on our page on G98 and G99 grid connection, and the same rule is what caps most British systems at a 3.68kW inverter regardless of how many panels are on the roof.
Note what the manual does to the bigger models in the same family. The SPH 4000, 4600, 5000 and 6000 all have a rated output apparent power of 4,000VA in stand-alone backup mode, so paying for a 6kW hybrid does not buy you 6kW of backup. If backup output is the reason you are buying, that number is the one to check, and it is the same check we apply on the Tesla Powerwall 3, where the backup rating and the grid rating are the same figure.
What Growatt kit costs in the UK
Growatt hardware is priced well below the European and American brands, and a British homeowner can see the actual numbers because several UK retailers publish them, which most battery manufacturers do not. These were the listed prices at Eco Angels, a UK retailer, on 26 September 2026. Stock moves and prices move with it, so treat them as the shape of the market rather than today's quote.
| Product | Listed inc VAT | Listed excl VAT |
|---|---|---|
| MIC 2500 TL-X string inverter | £409.20 | £341.00 |
| MIN 3600 TL-X string inverter | £546.00 | £455.00 |
| MIN 3600 TL-XH hybrid inverter | £571.20 | £476.00 |
| MIN 6000 TL-XH hybrid inverter | £718.80 | £599.00 |
| ARK 2.5H-A1 battery module, 2.56kWh | £930.00 | £775.00 |
| ARK HV BMS controller | £870.00 | £725.00 |
| AXE 5.0L battery module, 5kWh | £1,620.00 | £1,350.00 |
A second UK retailer, The Eco Supermarket, listed the SPH3600TL BL-UP hybrid at £882.00 including VAT on the same day, and TradeSparky listed the same model at £931.81 including VAT. A spread of £50 on one model between two British sellers is normal and is worth ten minutes of your installer's time.
Two things in that table mislead if you read them quickly. The first is the ARK line: a 2.56kWh module at £930 works out at £363 per kilowatt hour, which looks reasonable until you notice the high-voltage BMS controller is a separate £870 item, so the first module on a new stack effectively costs £1,800 before you have anything that works. The AXE route at £1,620 for 5kWh, or £324 per kilowatt hour, reads better per unit of storage. The second is VAT, and it runs in your favour.
Those are supply-only retail prices, so they carry 20% VAT. When an installer supplies and fits the same kit in your home, HMRC's rules zero rate the whole job until 31 March 2027, and since 1 February 2024 that has explicitly covered electrical storage batteries in residential accommodation. From 1 April 2027 it reverts to the reduced rate of 5%, not to 20%. So the inc VAT column is what you pay buying the box on its own, and the excl VAT column is closer to what the hardware line on an installed quote should look like. The detail is on our page on VAT on solar panels.
None of this tells you the installed price. Scaffolding, an electrician, the grid application, the roof work and the installer's margin sit on top, and the Energy Saving Trust's current figure for a typical 4.5kWp system is around £7,600 all in, with battery storage adding roughly £5,000 to £8,000. Our guide to what solar panels cost in the UK breaks that down by system size.
The battery warranty: 10 years, unless it is three
Growatt's Battery Warranty Terms and Conditions give the ARK, AXE and APX batteries 10 years, and then, in the Warranty condition section, state that "the battery warranty would reduce to 3 years without monitoring". The document requires that the battery system "have to be monitored on Growatt monitoring platform". This is the single most important line in any Growatt quote, and almost nobody selling the kit mentions it.
It is a stricter arrangement than it first appears. It is not a request that you register the product once. It is a condition that the system stays connected, because Growatt's stated reason is that the platform "would monitor the battery's performance constantly, report battery failure when it occurs". If a claim is made on an unmonitored battery, the document puts the cost of proving the fault back on you: the installer or end user "is obliged to organize qualified personnel to conduct an onsite inspection and data collection".
The performance guarantee behind the 10 years is also weaker than the market standard. Growatt warrants that the battery "retains at least 60% of Nominal Operation Energy" over the 10 year period. For comparison, Tesla's European warranty document places the UK in a tier that retains 80% at 10 years, a difference we set out in full on the Powerwall 3 page. On a 5kWh AXE module, 60% retention means Growatt has met its obligation if the battery still holds 3kWh after a decade.
Then there is a throughput cap, which is the limit that actually bites first. The warranty table sets an energy throughput allowance for each model, and dividing it by the module's nominal energy gives the number of full cycles before the cap is reached:
| Model | Nominal energy | Throughput allowance | Full cycles | At one cycle a day |
|---|---|---|---|---|
| ARK 2.5L-A1 | 2.56kWh | 7MWh | about 2,730 | about 7 years 6 months |
| AXE 5.0L-C1 | 5kWh | 16.69MWh | about 3,340 | about 9 years 2 months |
| APX 5.0P-B1 | 5kWh | 15.3MWh | about 3,060 | about 8 years 5 months |
All three run out before the 10 year date at one full cycle a day, which is exactly how a battery paired with solar and a cheap overnight tariff gets used. The ARK runs out two and a half years early. This is the same structural point we found in the Fox ESS battery warranty, where the throughput cap also binds before the headline date, and it is why the number of years on the front of a battery warranty is rarely the number that governs.
Three smaller clauses are worth knowing. The warranty is non-transferable, so it does not follow the house to a buyer, which is worth weighing against what solar and storage do to a property's value. Installation "shall be completed within 3 (THREE) months from the date of delivery from Growatt", so kit that sat in a warehouse over a winter is outside the terms. And a claim must reach Growatt "within 14 days on the failure of the battery", which is a short window if a fault appears while you are away.
The inverter warranty says two different things
Growatt's UK Warranty Card states that the inverter carries "a Growatt factory warranty valid for 10 years from the date of installation and no more than five and a half years from the delivery date", and then, four paragraphs later in the same document, refers to buying an extension "based on the 5 year term of Growatt factory warranty". Growatt's global service commitment page uses the five year figure too, describing "5 years standard factory warranty, or extension warranty", and sets a different clock again: warranty runs from the installation date "and no more than six months after the delivery date from Growatt".
UK retailers advertise the longer figure. The Eco Supermarket's listing for the SPH3600TL BL-UP carries a "10-Year Warranty" badge. That is very likely correct for a UK-market unit, because the warranty card is the UK-specific document and it says 10 years. But the same card references a five year base term, and the global page says five, so a buyer reading three Growatt sources gets two answers.
The resolution is not to argue with the documents, it is to get the term written into your quote. Ask your installer to state the inverter warranty length in years on the quotation itself, with the commissioning date recorded, and keep the delivery paperwork. Both Growatt clocks are anchored to Growatt's own delivery date rather than to your purchase, so a unit that sat in a distributor's warehouse has already used some of your cover before it reaches your wall. The wider point, that an inverter is the part of a solar system most likely to need replacing at around 12 years, is covered on our solar inverters guide.
The cloud you have to stay connected to
In March 2025 the cybersecurity firm Forescout published research called SUN:DOWN that found 46 new vulnerabilities across three of the world's top ten solar inverter vendors, Sungrow, Growatt and SMA, and reported that "Growatt inverters were susceptible to cloud-based takeover, allowing unauthorized access and control of a user's resources, solar plants, and devices". Forescout states that following responsible disclosure, all vendors have patched the reported issues.
This matters more for Growatt than it would for most brands, because of the warranty condition above. On a Growatt battery system, staying connected to Growatt's monitoring platform is not optional convenience, it is what keeps the 10 year cover alive. The cloud service you are required to use is the one the research found had been reachable.
Two things have changed since. Growatt now publishes Vulnerability Handling Guidelines on its support pages, covering inverters, energy storage, the ShineWiFi, ShineLan and Shine4G monitoring products and the Shine Server platform and ShinePhone app. It commits to confirming receipt of a report within 48 hours, assessing within 10 business days, and aiming to fix confirmed vulnerabilities within 90 days. A published disclosure process is a low bar, but it is a bar a great many hardware vendors still do not clear, and it did not exist before.
For a homeowner the practical steps are unglamorous and take five minutes: change the default password on the monitoring account, do not reuse a password from anywhere else, put the inverter's Wi-Fi dongle on a guest network if your router supports one, and let firmware updates install. None of that is specific to Growatt. It applies to every internet-connected inverter, including the ones on our SolarEdge and Sunsynk pages, both of which also tie warranty or functionality to a cloud connection.
Where Growatt fits, honestly
Growatt is the value option and it does not pretend otherwise. If the quote in front of you is several hundred pounds cheaper than the alternatives and the difference is the inverter brand, Growatt is usually why. The hardware is widely fitted, spares are available, and Growatt says it will keep supplying parts after the warranty expires "with a price not exceed the previous order price" and will give six months' notice before discontinuing a product.
What you are giving up is warranty strength. Sixty per cent capacity retention at 10 years is the weakest headline in this class. The throughput caps bind before the date on every residential model. The cover halves and more if the system goes offline. The claim window is 14 days. And labour, logistics and lost export income are all excluded, so a failure in year seven means a free part and an invoice from an electrician.
That is a reasonable trade if the saving is real and you intend to keep the system online and monitored anyway, which most people do. It is a poor trade if you are choosing Growatt to save £300 on a system you will not check again for a decade. The way to tell which you are looking at is to get the same system priced with a different inverter, side by side, and read the warranty line on both. Three itemised quotes will show you the gap in an afternoon, and whether a battery earns its place at all is a separate question we cover on solar battery storage.
Ask installers to quote your roof with a Growatt inverter and with one alternative, listing the panel, inverter, battery, warranty term and grid application as separate lines.
Get a Quote →Frequently asked questions
They are competent budget hardware with a weaker warranty than the premium brands. Growatt is one of the world's ten largest inverter vendors and its kit is widely fitted in Britain, priced several hundred pounds below European alternatives: a MIN 3600 TL-X string inverter listed at £546 including VAT at a UK retailer on 26 September 2026. The trade-off is in the paperwork rather than the electronics. Growatt's battery warranty guarantees only 60% capacity retention at 10 years, sets throughput caps that run out before the 10 year date, and reduces to three years if the system is not kept connected to Growatt's monitoring platform.
Ten years, reducing to three years without monitoring. Growatt's Battery Warranty Terms and Conditions for the ARK, AXE and APX ranges provide a non-transferable 10 year warranty for the EU, UK, USA and Australia, but the Warranty condition section requires that the battery system be monitored on the Growatt monitoring platform and states that the warranty "would reduce to 3 years without monitoring". The 10 year term also carries an energy throughput cap and guarantees only that the battery retains at least 60% of its nominal operation energy.
Yes, and on every residential model it runs out before the 10 year date at one cycle a day. Growatt's warranty sets an energy throughput allowance per model: 7MWh for the 2.56kWh ARK 2.5L-A1, 16.69MWh for the 5kWh AXE 5.0L-C1 and 15.3MWh for the 5kWh APX 5.0P-B1. Divided by nominal energy that is roughly 2,730, 3,340 and 3,060 full cycles, or about seven years six months, nine years two months and eight years five months at one full cycle a day. A battery cycled daily on solar and a cheap overnight tariff will reach the throughput cap before it reaches the date.
Growatt's UK Warranty Card says 10 years from the date of installation, and UK retailers advertise 10 years. The same card also refers to an extension "based on the 5 year term of Growatt factory warranty", and Growatt's global service commitment page describes a "5 years standard factory warranty". Both documents also cap the clock against Growatt's delivery date rather than your purchase date, the UK card at five and a half years and the global page at six months. Get the term written on your quotation in years, with the commissioning date recorded, and keep the delivery paperwork.
Because 3,680W is exactly 16A at 230V, the UK grid connection threshold. Growatt's SPH-UP installation manual gives the SPH 3600TL BL-UP a rated input and output power of 3,680W and rated output apparent power of 3,680VA. The Energy Networks Association's rules apply EREC G98 to a generator of less than 3.68kW per phase, which lets your installer connect first and notify the network operator afterwards, and EREC G99 above it, which requires an application and approval before anything is energised. Inverters are commonly rated at 3,680W so an installation stays on the simpler side of that line.
Vulnerabilities were found by researchers and patched, not exploited in a reported attack on customers. Forescout's SUN:DOWN research, published 27 March 2025, identified 46 new vulnerabilities across Sungrow, Growatt and SMA, and reported that Growatt inverters "were susceptible to cloud-based takeover, allowing unauthorized access and control of a user's resources, solar plants, and devices". Forescout states that following responsible disclosure, all vendors have patched the reported issues. Growatt now publishes Vulnerability Handling Guidelines committing to acknowledge reports within 48 hours and aim to fix confirmed vulnerabilities within 90 days.
Yes, if you want the full warranty. Growatt's battery warranty states that the battery system "have to be monitored on Growatt monitoring platform" and that the warranty "would reduce to 3 years without monitoring". Growatt's reason is that the platform monitors performance continuously and reports failures, allowing remote diagnosis. If you claim on an unmonitored battery, the document places the burden on you: the installer or end user is obliged to organise qualified personnel to carry out an onsite inspection and data collection.
Not on a supply-and-install job in a home before 31 March 2027. HMRC's VAT Notice 708/6 zero rates the installation of specified energy-saving materials until 31 March 2027, and since 1 February 2024 that has included electrical storage batteries in residential accommodation. From 1 April 2027 it reverts to the reduced rate of 5%, not to 20%. Buying a Growatt inverter or battery on its own from a retailer without installation is standard rated at 20%, which is why UK retail listings show both an inc VAT and an excl VAT price.
No. Growatt's Battery Warranty Terms and Conditions describe a "non-transferable warranty", so it does not pass to a buyer with the property. The document also requires that installation be completed within three months of delivery from Growatt, and that a claim reaches Growatt within 14 days of the battery failing. Labour costs, logistics fees and lost electricity income are all expressly excluded from what the warranty covers, so a covered failure still leaves you paying an electrician.
Sources checked live on 26 September 2026: Growatt Products Service Commitment and Vulnerability Handling Guidelines (en.growatt.com/support/warranty); Growatt Warranty Card, UK; Growatt Battery Warranty Terms and Conditions, document GR-WT-2406-A-00, covering ARK, AXE and APX; Growatt SPH 3000-6000TL BL-UP installation manual; Growatt product catalogue; Companies House register, company 08660706; Eco Angels, The Eco Supermarket and TradeSparky UK product listings; Forescout Vedere Labs SUN:DOWN research, published 27 March 2025; HMRC VAT Notice 708/6; Energy Networks Association connection guidance; Energy Saving Trust solar panels guide, last updated 1 October 2026.