SolaX Inverter Review UK
SolaX inverter review UK 2026: X1 and X3 hybrid G4, warranty, app and faults
Checked against SolaX datasheets and UK warranty terms. Prices are indicative UK ranges with 0% VAT. Sources
The short version
SolaX is a value-tier hybrid brand: proven X1 and X3 hardware, built-in backup (EPS), and a 10-year inverter warranty that only applies if the inverter stays online. The catches are real. The Wi-Fi dongle is the weak link, SolaX is not on Octopus’s Intelligent Flux list, it is made in China so the UK security debate applies, and help runs through wholesalers and your installer. Buy it for the hardware and price, and buy it from an installer you expect to be trading in year seven.
This SolaX inverter review is written for UK homes comparing an X1 or X3 hybrid with a T-BAT battery. Specifications come from SolaX datasheets and its UK warranty terms, prices from our own bands, and I flag anything that changes by model or document version.
Which SolaX model is which
| Model | Phase and size | Battery side | Best for |
|---|---|---|---|
| X1-Hybrid G4 | Single-phase, 3.0 to 7.5 kW | DC-coupled, high-voltage | The default UK home: new solar plus battery, with EPS backup |
| X1-Fit G4 / X1-AC | Single-phase, Fit 3.7–7.5 kW, AC 3–5 kW | AC-coupled | Adding a battery to existing solar |
| X3-Hybrid G4 | Three-phase, 5 to 15 kW | DC-coupled, high-voltage | Three-phase supplies, bigger homes, EVs |
| X1-Boost G4 | Single-phase string inverter | None | Panels only. It is not a battery inverter |
Most 2026 quotes for single-phase homes use the X1-Hybrid G4, usually at 3.7 to 6 kW. Three-phase homes should look at the X3-Hybrid G4.
The grid route affects timing and cost. A 3.7 kW unit (3.68 kW) can follow G98: your installer fits it, then notifies the network operator within 28 days. The 5, 6 and 7.5 kW units normally need a G99 application approved before installation, unless a permanent export limit keeps you at 3.68 kW. Get the route in writing. Two X1-Hybrid units can also run in parallel for up to 15 kW.
Backup, efficiency and the datasheet
The X1-Hybrid G4 has a built-in EPS output with a quoted switchover under 10 ms, so most household electronics ride through a cut, and it can supply 150% of rated EPS power for 10 seconds. SolaX also quotes up to 97.6% peak efficiency, 200% PV oversizing, 16 A per input, IP65 and a −35 to +60°C range with derating above 45°C. These are manufacturer figures, so confirm them against the datasheet for the exact model on your quote.
A standard grid-tied system shuts down in a cut. EPS is what lets a hybrid keep chosen circuits running, and it only powers the circuits your installer wired to the backup port. Agree that list before installation day and ask for a live test at handover: open the main switch and see what stays on. On three-phase X3 units, ask what stays live per phase rather than assuming whole-house cover. Our guide to what solar panels do in a power cut explains the basics.
T-BAT batteries and third-party kit
SolaX’s Triple Power (T-BAT) range is high-voltage lithium iron phosphate, built from 5.8 kWh T58 modules and smaller 3.0 kWh T30 modules, stackable to roughly 23 kWh. We put a 5.8 kWh SolaX battery at £3,000–£4,000 installed in our Growatt vs GivEnergy vs SolaX comparison.
Two checks before you sign. First, the 10-year battery warranty comes with a throughput limit. SolaX’s 2023 EU battery terms list 17.9 MWh for a T58 module, which is about 3,100 full cycles, or roughly 8½ years of one cycle a day. I could not confirm the UK figure, so ask your installer for the document that applies to your serial number. Second, SolaX publishes a third-party battery list, but its inverter warranty excludes damage caused by unauthorised third-party control hardware or software. Stick to SolaX packs unless your installer will put any other arrangement in writing.
The warranty condition most buyers miss
Online or only five years
SolaX’s current UK and Ireland terms give G4 hybrids 5 years as standard, upgraded free to 10 years once the inverter is connected to SolaXCloud and uploading generation data. X1-Hybrid-LV models also need a SolaX battery. A dongle that stays offline can quietly cost you five years.
Older UK documents (2023) listed 5 years plus 5 years of parts-only cover for the same models, so check which version your installer registered. SolaX’s UK terms have also set a 90-day window to register after commissioning, and paid 5- or 10-year extensions have been sold through distributors within six months of installation. Claims are refused if a failure is not reported within four weeks, if the unit is moved after installation, or if unauthorised third-party control kit is fitted. Accessories such as the Pocket Wi-Fi dongle, meter and EPS box carry 2 years.
Register the warranty yourself on day one, keep the commissioning sheet and serial numbers, and ask in writing who pays for labour after year five. Our solar warranty explainer shows how the layers of cover fit together.
SolaX prices in 2026
| Setup (excluding panels) | Indicative installed price | How we get there |
|---|---|---|
| X1-Hybrid G4 + one 5.8 kWh T-BAT | £4,500–£5,500 | Battery band of £3,000–£4,000 plus hybrid inverter and commissioning |
| X1-Fit G4 or X1-AC + one 5.8 kWh T-BAT | £4,000–£5,500 | Storage added to existing solar, so no new array work |
| X3-Hybrid G4 + about 11.6 kWh T-BAT | £7,000–£9,500 | Our 10 kWh battery band of £4,000–£6,000 plus a three-phase inverter |
These are SolarBriton planning ranges, not quotes. Scaffolding, consumer-unit work and region move them, so compare three MCS quotes. Installer-fitted solar and batteries in Great Britain are charged 0% VAT until 31 March 2027, then 5% (HMRC notice 708/6); Northern Ireland differs. For whole-system numbers see what a solar system costs and our grants and VAT guide.
SolaXCloud and the Pocket Wi-Fi dongle
We score SolaXCloud 7.5 out of 10: clean and quick, a little corporate, and behind the best manufacturer apps (see our monitoring app comparison). The weak link is the plug-in dongle, not the app. It drops out after router changes and in garages with poor signal, and owners report the same thing.
Give the dongle a 2.4 GHz network, re-pair it through the app or its setup page, and move to the LAN or 4G option where signal is poor. Treat it as warranty-critical, since the free 10-year upgrade needs uploaded data. Generation continues while the app shows offline; our solar inverter offline guide covers the general fix.
SolaX and Octopus tariffs
SolaX was not on Octopus’s Intelligent Flux integration lists when we checked on 23 September 2026, and it sits on the “coming soon” list for Charge Pack. You can still run Agile and standard Flux by setting charge windows yourself or through a control app. If you want Octopus to schedule the battery, shortlist Fox ESS, Sigenergy, Tesla or Enphase and confirm eligibility in your account. Details are in our Agile and Flux battery guide, and our SEG rate ranking covers export pay.
Support, security and supplier risk
SolaX Power Network Technology (Zhejiang) is based in Hangzhou. UK help runs through wholesalers and your installer, with an escalation route to SolaX’s service team. Trustpilot reviews of SolaXCloud mix praise with complaints about slow replacement parts and trouble reaching SolaX once an installer has stopped trading.
The 2026 lesson is GivEnergy, which entered administration on 9 April 2026 with no further hardware warranties honoured (our explainer). SolaX is trading normally, but a warranty is only as good as the claim route behind it, so keep your MCS certificate and paperwork. On security, there is no UK ban on Chinese-made inverters, and the PSTI Act has banned default passwords since 29 April 2024. Use a unique password, update firmware and put the dongle on a guest network. Our kill-switch explainer and report on 93 inverter flaws go deeper.
Common SolaX problems and first moves
| Problem | Usual cause | First move |
|---|---|---|
| Trips on sunny middays (“Grid Volt Fault”) | Local voltage above the 253 V limit while you export, a network condition | Log times and voltages; your installer raises it with the DNO. Do not edit the grid profile |
| App offline, generation fine | Dongle dropout or a router change | Re-pair on 2.4 GHz, or fit a LAN or 4G dongle |
| Battery comms fault | Can follow a firmware update that leaves inverter and battery versions mismatched | Installer aligns firmware versions via the portal |
| Backup misses expected circuits | Those circuits were never wired to the EPS port | Check the as-installed circuit schedule. This is configuration, not repair |
| Insulation or RCD faults (“RCD Fault”) | Usually the array: wet connectors or damaged DC cable | Isolate and test the strings; do not keep resetting |
| Summer derating | Ambient temperature above about 45°C, often in lofts | Ventilate or relocate the unit |
Only the dongle and firmware rows are specific to SolaX. The rest are grid and wiring issues any brand has. Decode your display with our fault codes guide, and see inverter replacement costs if the unit is out of warranty.
SolaX vs Fox ESS, Sungrow and Sunsynk
| Brand | Battery approach | Warranty | Intelligent Flux | Read next |
|---|---|---|---|---|
| SolaX | Own T-BAT; third-party list is narrow | 5 yrs, 10 once online; battery 10 | Not listed | This review |
| Fox ESS | Fox packages | 10 yrs once registered | In sign-up list | Fox ESS H3 review |
| Sungrow | Own SBR/SBH only, modular | 10 yrs, with caps | Not listed | Sungrow review |
| Sunsynk | 48 V batteries, wide list | 5–10 yrs by model | Not listed | Sunsynk review |
Based on SolarBriton’s own 2026 guides. Check each brand’s current terms before buying.
Verdict: who should buy SolaX
Buy SolaX if you want hybrid backup at value-tier money, your home is three-phase, or you are adding storage to existing panels through the X1-Fit G4 or X1-AC. A well-sized system sits inside the normal payback range in our payback guide, and panel choice matters as much as the inverter (see the 2026 panel guide).
Look elsewhere if you want Octopus to run the battery, you want freedom to mix battery brands, or the app is your daily interface and you want the best one. Either way, choose your installer carefully or find an installer through us.
One-line summary
Good hardware at a fair price, with a warranty that depends on keeping it online and a support chain that depends on your installer.
Frequently asked questions
Is SolaX a good inverter brand in the UK?
Yes, for most homes. The X1-Hybrid G4 has built-in backup (EPS), the hardware is widely fitted, and the three-phase X3 range covers larger houses. The trade-offs are a dongle that drops offline, no Octopus Intelligent Flux support, and help that runs through distributors and your installer. Choose an installer who will still be trading in year seven.
How long is the SolaX inverter warranty in the UK?
G4 hybrids carry 5 years as standard. SolaX’s current UK and Ireland terms upgrade this free to 10 years once the inverter is connected to SolaXCloud and uploading data. Batteries carry 10 years with a throughput limit. Older UK documents listed 5 years plus 5 years of parts-only cover, so check which version your installer registered.
What is the difference between SolaX X1 and X3 inverters?
Phase count. X1 models are single-phase and suit most UK homes, with the X1-Hybrid G4 covering 3.0 to 7.5 kW. X3 models are three-phase, and the X3-Hybrid G4 runs from 5 to 15 kW for larger homes with three-phase supplies. Choose by your supply and load, not by features.
Does SolaX work with Octopus Intelligent Flux?
Not at the moment. SolaX was not on Octopus’s Intelligent Flux integration lists when we checked on 23 September 2026. You can still use Agile and standard Flux by setting charge and discharge times yourself or with a control app. Check your Octopus account before buying if automatic control matters.
Can I add a SolaX battery to existing solar panels?
Yes. SolaX sells AC-coupled retrofit inverters, the X1-Fit G4 and X1-AC, which add storage beside your existing inverter. Your installer can also replace the old inverter with an X1-Hybrid G4 and reuse the panels. Ask for both options to be priced. The X1-Boost is a panels-only inverter and cannot run a battery.
Why does my SolaX inverter show offline in the app?
Usually the Pocket Wi-Fi dongle has lost its connection, often after a router change, and generation continues. Re-pair it on a 2.4 GHz network or switch to a LAN or 4G dongle. Fix it promptly, because the free 10-year warranty upgrade depends on the inverter uploading data to SolaXCloud.
Sources
Last updated 12 October 2026. Specifications are manufacturer figures and can change between versions. Prices are indicative. This is general guidance, not electrical or financial advice, so confirm details with your installer and SolaX.
