- 1Sunsynk is one of the UK’s most popular hybrid inverter brands, with UK office in Wrexham, European HQ in Netherlands, and proven Deye manufacturing.
- 2Built-in Octopus Agile integration – automatic charging during cheap periods and discharging during expensive half-hours, with 6 programmable time slots.
- 3IP65 weatherproof rating – suitable for outdoor installation without enclosure, plus built-in generator port, smart load output, and UPS backup under 10ms.
- 4Extensive battery compatibility – works with Pylontech, BYD, Dyness, and many third-party brands, plus own CATL batteries with 6,000+ cycle life.
Sunsynk has rapidly established itself as one of the most popular hybrid inverter brands in the UK residential solar market. The company offers a comprehensive range of single-phase and three-phase hybrid inverters designed for grid-tied, off-grid, and backup power applications. With features including dual MPPT solar inputs, IP65 weatherproof ratings, built-in Wi-Fi monitoring, and direct integration with Octopus Energy’s Agile tariff, Sunsynk inverters provide a compelling package for homeowners seeking energy independence and bill savings.
Established over 20 years ago, Sunsynk is headquartered in Hong Kong with a European office in the Netherlands and a dedicated UK support team based in Wrexham. The company’s inverters are manufactured by Ningbo Deye Inverter Technology, one of China’s largest inverter producers, meaning Sunsynk products share core technology with the Deye brand whilst offering differentiated firmware, monitoring software, and local support infrastructure.
This review examines Sunsynk’s complete UK product range including the popular ECCO hybrid inverter series, CATL battery storage modules, the new Acure next-generation inverters, and the Sunsynk Connect monitoring app. We compare Sunsynk to alternatives like GivEnergy, SolaX, and Fox ESS.
Why People Choose It
- Built-in Octopus Agile integration
- IP65 outdoor installation rating
- Generator input included (built-in port)
- Extensive third-party battery support
- Up to 16 units parallel capability
- 6 programmable time slots
- UK support team in Wrexham
- Competitive pricing vs premium brands
- Under 10ms UPS transfer time
- Proven Deye manufacturing at scale
Considerations
- 5-year warranty (vs 10-12 years from competitors)
- Same hardware available as Deye at 15-20% lower price
- Some app reliability reports
- Third-party battery setup can require correct cables
- Check current MCS status for SEG eligibility
- Internal fan (not fanless like some competitors)
- Firmware requires online connection for full functionality
- Variable installer experience levels
SolarLove Rating
Based on performance, value, reliability, and support
ECCO 8kW + CATL 10.24kWh (2 x 5.12kWh)
- 8kW continuous output (8.8kW peak)
- 10.4kW max PV input on dual MPPT
- IP65 outdoor installation ready
- Built-in Octopus Agile integration
- Generator port + smart load output
- CATL 6,000+ cycle battery modules
- Under 10ms UPS backup transfer
- Sunsynk Connect monitoring app
Company Background
Sunsynk has built a strong presence in the UK and South African solar markets, becoming one of the most installed hybrid inverter brands in both countries. The company focuses exclusively on solar storage solutions, developing inverters, batteries, and monitoring systems designed to work together as an integrated ecosystem. Sunsynk’s products are particularly popular among installers due to their straightforward setup, comprehensive feature set, and competitive pricing.
Manufacturing Partnership with Deye
Sunsynk inverters are manufactured by Ningbo Deye Inverter Technology Co., Ltd., a publicly traded Chinese company (Shanghai Stock Exchange: 605117.SH) founded in 2007. Deye is one of the world’s largest inverter manufacturers with registered capital of 300 million RMB. This OEM relationship means Sunsynk and Deye inverters share identical core hardware, PCB designs, and internal components. The key differences lie in the exterior casing colour, user interface design, firmware features, monitoring software, and local support infrastructure.
| Aspect | Sunsynk | Deye |
|---|---|---|
| Hardware | Identical (same factory) | Identical (same factory) |
| Monitoring app | Sunsynk Connect | SolarMan |
| UK support | Dedicated UK team (Wrexham) | Importer-based |
| Octopus integration | Built-in | Via third-party |
| Typical UK price | Standard | 15-20% lower |
ECCO Hybrid Inverter Range
The ECCO series represents Sunsynk’s core hybrid inverter range, offering models from 3.6kW to 16kW in single-phase configurations. These inverters combine solar MPPT charge control, battery management, grid connection, and backup power functionality in a single IP65-rated unit suitable for indoor or outdoor installation. All ECCO models feature dual MPPT inputs (three MPPTs on 12kW and 16kW models), built-in Wi-Fi monitoring, LCD touchscreen displays, and compatibility with both lithium-ion and lead-acid batteries.
| Series name | ECCO |
| Single-phase models | 3.6kW, 5kW, 5.5kW, 7kW, 8kW, 10kW, 12kW, 16kW |
| Three-phase models | 8kW, 10kW, 12kW, 20kW, 25kW, 30kW, 50kW |
| MPPT trackers | 2 (3 on larger models) |
| IP rating | IP65 (weatherproof) |
| Operating modes | Grid-tie, off-grid, hybrid, UPS backup |
| Battery types | Lithium-ion and lead-acid |
| Parallel capability | Up to 16 units (same firmware) |
| Generator input | Yes (built-in port) |
Single-Phase ECCO Specifications
| Model | ECCO 3.6kW | ECCO 5kW | ECCO 8kW | ECCO 12kW |
|---|---|---|---|---|
| Rated output | 3,600 W | 5,000 W | 8,000 W | 12,000 W |
| Max AC output | 3,960 W | 5,500 W | 8,800 W | 13,200 W |
| Max PV input | 7,000 W | 6,500 W | 10,400 W | 18,000 W |
| Max PV voltage | 500 V | 500 V | 500 V | 500 V |
| MPPT trackers | 2 | 2 | 2 | 3 |
| Max charge current | 120 A | 120 A | 190 A | 250 A |
| Max efficiency | 97.6% | 97.6% | 97.6% | 97.6% |
| Weight | 25 kg | 26 kg | 32 kg | 36 kg |
Key Features
| Dual MPPT | Independent tracking for different roof orientations or partial shading |
| IP65 rating | Weatherproof for outdoor installation without enclosure |
| Zero export | Prevents excess energy feeding back to grid (DNO compliance) |
| Generator port | Accepts AC input from generator, microinverters, or wind turbine |
| Smart load output | Programmable auxiliary output for high-power appliances |
| Time-of-use | 6 programmable time slots for charge and discharge |
| Transfer time | Less than 10 ms (UPS mode) |
| Surge capacity | 50% above rated power for motor starting |
Operating Modes
| Grid-tie | Solar feeds loads and exports excess; no battery required |
| Hybrid | Solar charges battery and feeds loads; grid supplements when needed |
| Off-grid | Operates independently of grid using solar and battery |
| UPS backup | Provides uninterrupted power during grid outages |
| Battery only | Charges battery from grid for time-of-use arbitrage |
| Sell mode | Discharges battery to grid during high-price periods |
Three-Phase Inverters
Sunsynk offers three-phase hybrid inverters for larger residential and commercial installations. These models share the same core technology as the single-phase ECCO range but are designed for three-phase electrical supplies common in larger UK homes and business premises. Three-phase models range from 8kW to 50kW, with the ability to parallel multiple units for even larger systems.
| Model | 8kW 3-Phase | 12kW 3-Phase | 25kW 3-Phase | 50kW 3-Phase |
|---|---|---|---|---|
| Rated output | 8,000 W | 12,000 W | 25,000 W | 50,000 W |
| Max PV input | 10,400 W | 18,000 W | 32,500 W | 65,000 W |
| Max PV voltage | 800 V | 800 V | 800 V | 1,000 V |
| MPPT trackers | 2 | 2 | 3 | 4 |
| Max efficiency | 97.6% | 97.6% | 98% | 98.4% |
Sunsynk CATL Battery Range
Sunsynk manufactures its own lithium iron phosphate (LiFePO4) battery modules using cells from CATL, one of the world’s largest battery cell producers supplying automotive brands including BMW, Tesla, and Daimler. The batteries feature 100% depth of discharge, sophisticated battery management systems, and can be paralleled to create storage systems up to 81.9 kWh. Both rack-mounted and IP65-rated wall-mounted versions are available.
| Cell manufacturer | CATL |
| Chemistry | Lithium Iron Phosphate (LiFePO4) |
| Module capacities | 5.12 kWh, 5.32 kWh, 10.65 kWh |
| Nominal voltage | 51.2 V |
| Depth of discharge | 100% |
| Max parallel units | 16 (up to 81.9 kWh) |
| Cycle life | 6,000+ cycles (80% capacity retention) |
| Product warranty | 5 years |
| Performance warranty | 10 years (80% capacity) |
Battery Specifications
| Model | CATL 5.12kWh | L5.1 (IP65) | CATL 10.65kWh |
|---|---|---|---|
| Capacity | 5.12 kWh | 5.12 kWh | 10.65 kWh |
| Max continuous discharge | 100 A (1C) | 100 A | 200 A |
| IP rating | IP21 (indoor) | IP65 (outdoor) | IP21 (indoor) |
| Form factor | Rack mount (3U) | Wall mount | Rack mount |
| Weight | 42 kg | 52 kg | 85 kg |
Third-Party Battery Compatibility
Sunsynk inverters support a wide range of third-party lithium batteries through CAN and RS485 communication protocols. This flexibility allows homeowners to choose batteries based on specific requirements, budget, or existing equipment.
| Brand | Compatible Models |
|---|---|
| Pylontech | US2000C, US3000C, US5000, UP5000, Force-L2 |
| BYD | Battery-Box LV range |
| Dyness | Tower range, PowerBox |
| Hubble | AM-2, AM-4, AM-5 |
| Pytes | E-Box range |
| FreedomWon | Lite range |
Sunsynk Connect Monitoring
Sunsynk Connect is the company’s proprietary monitoring platform, available as both a mobile app (iOS and Android) and web portal. The platform provides real-time monitoring of energy generation, consumption, battery status, and grid interaction. A key differentiator is the direct integration with Octopus Energy’s Agile tariff, allowing the inverter to automatically optimise charging and discharging based on half-hourly electricity prices.
| App name | Sunsynk Connect (formerly Sunsynk Logger) |
| Platforms | iOS, Android, web browser |
| Real-time monitoring | Yes (via Wi-Fi dongle) |
| Remote settings | Full inverter control from app |
| Historical data | Day, week, month, year, and custom reports |
| Alerts | Push notifications for faults, warnings, power loss |
| Firmware updates | Remote OTA updates via app |
| Data hosting | Premium UK and EU servers |
Octopus Agile Integration
Sunsynk inverters feature built-in integration with Octopus Energy’s Agile tariff, which offers half-hourly variable electricity pricing. The Sunsynk Connect app displays live Agile prices and allows users to configure automatic charging during low-price periods and discharging during expensive periods.
| Tariff supported | Octopus Agile |
| Price display | Live half-hourly prices in app |
| Auto scheduling | Charge during cheap periods |
| Export optimisation | Discharge during expensive periods |
| 6 time slots | Manual override scheduling available |
| Flux support | Compatible with Octopus Flux tariff |
Sunsynk vs Competitors
| Aspect | Sunsynk | GivEnergy | SolaX | Fox ESS |
|---|---|---|---|---|
| Country | Hong Kong (Deye) | UK (China mfg) | China | China |
| Hybrid range | 3.6-50 kW | 3-6 kW (Gen 3) | 3-15 kW | 3-12 kW |
| IP rating | IP65 | IP65 | IP65 | IP65 |
| Octopus integration | Built-in Agile | Via app | Via app | Via app |
| Generator input | Yes (built-in) | No | Some models | Yes |
| Parallel units | Up to 16 | Up to 5 | Up to 10 | Up to 10 |
| Third-party batteries | Extensive | Limited | Extensive | Extensive |
| Standard warranty | 5 years | 12 years | 10 years | 10 years |
| Price positioning | Budget to mid | Mid to premium | Budget to mid | Budget |
Pricing
| Product | Typical UK Price |
|---|---|
| ECCO 3.6kW single-phase | £700 – £900 |
| ECCO 5kW single-phase | £850 – £1,100 |
| ECCO 8kW single-phase | £1,200 – £1,500 |
| ECCO 12kW single-phase | £1,600 – £2,000 |
| 8kW three-phase | £1,500 – £1,900 |
| CATL 5.12kWh battery | £1,200 – £1,600 |
| L5.1 5.12kWh (IP65) | £1,400 – £1,800 |
| Lifelynk X (3.6kW + 3.84kWh) | £2,200 – £2,800 |
Summary
Sunsynk has earned its position as one of the UK’s most popular hybrid inverter brands through a combination of comprehensive features, competitive pricing, and accessible local support. The ECCO range offers everything most homeowners need from a hybrid inverter, including dual MPPT inputs, weatherproof construction, built-in generator input, programmable time-of-use scheduling, and seamless Octopus Agile integration. The ability to parallel up to 16 units provides scalability for growing energy needs or larger installations.
The primary consideration is the shorter 5-year warranty compared to GivEnergy’s 12 years or SolaX’s 10 years. However, Sunsynk’s proven Deye manufacturing heritage and competitive pricing help offset this concern. For budget-conscious buyers, it is worth noting that identical hardware is available under the Deye brand at approximately 15 to 20% lower cost, though with less comprehensive UK support infrastructure.
Overall, Sunsynk represents excellent value for UK homeowners seeking a feature-rich hybrid inverter with flexible battery compatibility and effective time-of-use optimisation. The combination of IP65 weatherproofing, built-in Octopus integration, and comprehensive monitoring makes ECCO inverters particularly well-suited to the UK market.
Compare Sunsynk with alternatives in our best solar inverters guide. For typical system costs, see our solar panel costs guide. To estimate savings for your home, try our solar panel calculator.
