Sunsynk L5.1 with ECCO inverter
The Sunsynk L5.1 with ECCO inverter stores 4.61 kWh usable. 48 V low-voltage battery modules with a Sunsynk ECCO hybrid inverter; the inverter supports DC or AC coupling to existing solar. Running essentials only, a full ECCO 3.6 kW + 2 × L5.1 (9.2 kWh) lasts about 2 days 8 hours in a power cut.
A 5.12 kWh, 48 V wall-mounted battery module (4.61 kWh usable) used with Sunsynk's ECCO hybrid inverters. Add modules in parallel for more storage.
Last checked 26 Sept 2026 · Sources listed at the bottom of the page
- Sunsynk recommends 50 A per module (about 2.5 kW) and allows up to 100 A. With only one or two modules, the full inverter output may not be sustained for long.
- The warranty doesn't guarantee a minimum capacity after a set number of years.
- Round-trip efficiency isn't stated on the battery datasheet.
- Our ECCO inverter datasheet is version 4 (March 2023), the newest we found for the 3.6 kW and 5 kW models.
How long will it run your home?
Pick a setup and tick what you want to keep running. The maths is shown below the result.
Average draw 156 W from 8.76 kWh available.
Everything on at once: 415 W — within the 3.6 kW limit
- Starts from a full battery with 0% held back as reserve.
- 5% extra allowed for wiring and standby losses on top of the manufacturer's usable figure.
- Appliance figures are typical averages; your own may differ. Enter your own wattage for the most accurate result.
- Assumes no solar recharging during the outage.
Setups you can buy
| Setup | Usable energy | Continuous power |
|---|---|---|
| ECCO 3.6 kW + 2 × L5.1 (9.2 kWh) | 9.22 kWhcalculated | 3.6 kW |
| ECCO 5 kW + 2 × L5.1 (9.2 kWh) | 9.22 kWhcalculated | 5 kW |
| ECCO 5 kW + 3 × L5.1 (13.8 kWh) | 13.83 kWhcalculated | 5 kW |
Full specifications
| Specification | Value | Source |
|---|---|---|
| Capacity | ||
| Usable capacity (per unit) | 4.61 kWhPer module, 90% depth of discharge | Sunsynk datasheetp.2 |
| Total (nominal) capacity | 5.12 kWhPer module | Sunsynk datasheetp.2 |
| Depth of discharge | 90% | Sunsynk datasheetp.2, Recommend Depth of Discharge |
| Battery chemistry | LFP (LiFePO₄) | Sunsynk datasheetp.2 |
| System | ||
| Maximum usable storage (expanded) | Not documented in the sources we hold | |
| How it expands | Up to 32 modules in parallel (163.8 kWh total energy) | Sunsynk datasheetp.2, Scalability |
| Maximum system power (expanded) | Not documented in the sources we hold | |
| Architecture | 48 V low-voltage battery modules with a Sunsynk ECCO hybrid inverter; the inverter supports DC or AC coupling to existing solar | Sunsynk datasheetp.1 |
| Grid connection | Single phase | Sunsynk datasheetp.2, Grid Type |
| Power | ||
| Continuous power (per unit) | 3.6–5 kWECCO 3.6K: 3.6 kW · ECCO 5K: 5 kW (larger ECCO models also available) | Sunsynk datasheetp.2, Rated AC Output and UPS Power |
| Peak power | 7.2–10 kWcalculatedInverter: 2 × rated power for 10 s, off-grid. The batteries' current limits may allow less.How: 2 × rated power: 3.6 kW model 7.2 kW, 5 kW model 10 kW | Sunsynk datasheetp.2, Peak Power (off-grid) |
| Peak duration | 10 s | Sunsynk datasheetp.2 |
| Max charge power | Not documented in the sources we hold | |
| Round-trip efficiency | Not documented in the sources we hold | |
| Solar | ||
| Max solar input | 6.5–7 kWECCO 5K: 6.5 kW · ECCO 3.6K: 7 kW | Sunsynk datasheetp.2, Max. DC Input Power |
| Solar MPPT inputs | 2 | Sunsynk datasheetp.2 |
| Backup | ||
| Backup switchover time | Not documented in the sources we hold | |
| Backup needs | Not documented in the sources we hold | |
| Physical | ||
| Ingress rating | IP65 (battery and inverter) | Sunsynk datasheetp.2 |
| Indoor / outdoor | Not documented in the sources we hold | |
| Operating temperature | Charge 0°C to 55°C; discharge −20°C to 55°C | Sunsynk datasheetp.2, Working Temperature |
| Dimensions | 440 × 620 × 135 per moduleW × H × D, excluding breaker and terminals | Sunsynk datasheetp.2 |
| Weight | 50 kgPer module, approximate; ECCO inverter 20.5 kg | Sunsynk datasheetp.2 |
| Mounting | Wall-mounted or 19-inch cabinet | Sunsynk datasheetp.2, Installation |
| Warranty | ||
| Stated cycle life | Not documented in the sources we hold | |
| Warranty (UK) | 10 yearsBattery cells: 10 years or 6,000 cycles. Battery BMS: 5 years | Sunsynk warrantyp.1, §2 Battery warranty |
| Capacity guaranteed at end of warranty | Not documented in the sources we hold | |
| Warranty throughput limit | Not documented in the sources we hold | |
| Warranty conditions | After year 5, faulty cells are replaced free but labour isn't covered. Must be bought from Sunsynk or an authorised reseller, installed in a covered country (the UK is included) and cycled no more than 700 times a year. No capacity-retention figure is given. | Sunsynk warrantyp.1, §2, §4 and §5 |
| Compliance | ||
| UK grid compliance | G98, G99 (ECCO inverter) | Sunsynk datasheetp.3, Grid Regulation |
Questions people ask
How much usable capacity does the Sunsynk L5.1 with ECCO inverter have?
4.61 kWh (Per module, 90% depth of discharge).
Can the Sunsynk L5.1 with ECCO inverter be expanded?
Up to 32 modules in parallel (163.8 kWh total energy).
How long will the Sunsynk L5.1 with ECCO inverter run a house in a power cut?
Running essentials only (fridge-freezer, lights, Wi-Fi, TV and device charging, about 156 W on average), a full ECCO 3.6 kW + 2 × L5.1 (9.2 kWh) lasts roughly 2 days 8 hours. Heavy loads such as a heat pump, electric shower or EV charger cut this sharply. Use the calculator on this page with your own appliances.
What warranty does the Sunsynk L5.1 with ECCO inverter have in the UK?
10 years. Battery cells: 10 years or 6,000 cycles. Battery BMS: 5 years.
Head-to-head comparisons
Sunsynk L5.1 with ECCO inverter vs Fox ESS EVO 10
Capacity, power, warranty and runtime side by side.
Other batteries
Tesla Powerwall 3
An all-in-one home battery with a built-in solar inverter. One unit stores 13.5 kWh and can be expanded with up to three Expansion units.
Sigenergy SigenStor
A stackable system: a Sigen Energy Controller (hybrid inverter) with 1–6 battery modules of 5.2 or 7.8 kWh usable each.
Enphase IQ Battery 5P
An AC-coupled 5 kWh battery with six built-in microinverters, so it can be added to most existing solar systems. Up to seven can be combined in the UK.
myenergi libbi
A UK-designed modular battery with a 3.68 kW or 5 kW hybrid inverter and 1–4 battery modules (4.6 kWh usable each). Built to work with myenergi's zappi and eddi.
SolarEdge Home Battery 400V
A 9.7 kWh high-voltage battery that pairs with SolarEdge's single-phase Home Hub inverter. Up to three batteries per inverter. Octopus lists SolarEdge for Intelligent Octopus Flux.
Huawei LUNA2000-S1
A modular high-voltage battery with 6.9 kWh modules (1–3 per stack, up to 20.7 kWh). Used with Huawei's SUN2000 hybrid inverters.
Sources
- SUNSYNK-L5.1 datasheet — Sunsynk, v.6 (28/06/24). Retrieved 26 Sept 2026. Official Sunsynk datasheet (lists Sunsynk UK Ltd, Widnes) hosted by a distributor. A 2025 re-issue has the same figures.
- ECCO Hybrid Inverter SUN-3.6/5/6/7.6/8K-SG05LP1-EU datasheet — Sunsynk, v.4 (29/03/23). Retrieved 26 Sept 2026. Official Sunsynk datasheet hosted by UK retailer Bimble Solar.
- Manufacturer's Warranty — Warranty Agreement Terms and Conditions — Sunsynk. Retrieved 26 Sept 2026. Published on Sunsynk UK's website (Sunsynk Ltd, Widnes). The PDF is a scanned image; we read it visually.
Spotted an error? Every figure above links to the document it came from. See how we check data.