REFU 261
Compact AC energy storage system
- Capacity
- 261 kWh
- AC power
- 125 kW
- Cycles
- 8,000
At a glance
235 kWh
Usable capacity
LFP
Battery chemistry
Lithium iron phosphate
400 V
Rated voltage
≥ 90 %
Max. system efficiency
IP54
Protection rating
Corrosion protection C4
Liquid + air
Cooling
Liquid cooling and air cooling
Overview
The REFU 261 is a compact energy storage system for commercial and industrial applications. Its liquid-cooled pack-level architecture with active temperature balancing ensures stable performance and even cell temperatures. The modular design allows flexible parallel expansion. Storage and PV plant can be controlled and monitored centrally with REFUlink.
Performance & efficiency
- Pack-level liquid cooling with temperature balancing (≤ 3 °C)
- High energy density through optimised thermal design
- Stable performance under varying operating conditions
Installation & scalability
- Compact design, less than 1.5 m² footprint
- Modular design for flexible parallel expansion
- Integration into C&I energy storage applications
Safety & reliability
- LFP battery chemistry
- Integrated fire detection with aerosol fire suppression
- IP54 protection, C4 corrosion protection
Controlled with REFUlink
- Control and monitor storage and PV plant centrally
- Connection via Ethernet, RS485 and Modbus TCP/IP
Your benefit as …
Operators & investors
Real-time monitoring with REFUview
REFUview shows the status, output and yield of your PV plant in real time, on your computer and on your smartphone. Spot deviations early and protect your yield.
Data hosting in Germany
Your plant data is hosted and processed in Germany. This makes data protection and data sovereignty easier, especially for operators of critical infrastructure.
Technical support from Germany
For questions about operation, faults or firmware updates, you can reach our technical support in Germany, personally and without detours.
EPCs & general contractors
Datasheets, certificates and manuals in the download centre
Datasheets, unit certificates, declarations of conformity and manuals are all in one place in the download centre, always in the current version.
Personal contacts in sales and engineering
For system design, quotations and detailed technical questions, you talk directly to our sales team and our engineers, including for large solar parks.
Scalable with REFUlink and REFUview
REFUlink connects up to 60 inverters to the control room and the grid operator, while REFUview brings all operating data together. The system grows with your plant.
Installers & electrical contractors
Easy commissioning
Many models can be set up via app over Bluetooth directly at the inverter. This saves time when commissioning on commercial rooftops.
Technical support from Germany
For questions about installation, settings or error messages, you can reach our technical support in Germany, personally and without detours.
Fits new and existing systems
REFUsol inverters can be integrated into new and existing PV plants, and via REFUlink also together with older generations of REFU inverters.
Planners & engineers
Unit certificates and declarations of conformity in the download centre
Download the evidence you need for plant design, such as unit certificates to VDE-AR-N 4105 and 4110 or EN 50549, directly and without a request.
Complete technical data for comparison
Every product page shows all values from the datasheet, from the MPPT voltage range to the overvoltage category, clearly arranged by group.
Direct contact with engineering
For detailed questions on grid protection, reactive power or plant control, talk directly to our engineers, without detours.
Technical data
Datasheet (PDF) – DEBattery data
| Storage capacity | 261 kWh |
|---|---|
| Usable capacity | 235 kWh |
| Battery chemistry | LFP (lithium iron phosphate) |
| Cell specification | 314 Ah |
|---|---|
| Battery configuration | 1P52S |
| Max. charge/discharge rate | 0,5P |
AC data
| Rated output power | 125 kW |
|---|---|
| Rated voltage | 400 V |
| Rated current | 200 A |
|---|---|
| Nominal grid frequency | 50 / 60 Hz |
Performance & reliability
| Max. system efficiency | ≥ 90 % |
|---|
| Cycle life | 8,000 cycles at 25 °C, 80 % DoD |
|---|
Safety & protection
| Fire suppression system | Aerosol |
|---|---|
| Protection rating | IP54 |
| Cooling | Liquid cooling + air cooling |
|---|---|
| Corrosion protection class | C4 |
Communication
| Ethernet | Yes |
|---|---|
| RS485 | Yes |
| Modbus TCP/IP | Yes |
|---|
General data
| Operating temperature | −25 to +55 °C (derating above 45 °C) |
|---|---|
| Permissible humidity range | 0–95 % |
| Max. installation altitude | ≤ 3,000 m |
| Dimensions (W × D × H) | 980 × 1,300 × 2,350 mm |
|---|---|
| Weight | 2,900 kg |
Certification & compliance
| Standards | UN38.3, IEC 61000, IEC 62619, IEC 62477, IEC 63056, IEC 62933, UL 9540A, NFPA |
|---|
Data as of: 2 November 2026WEEE-Reg.-Nr. DE35952985Preliminary data based on the preliminary datasheetSubject to technical changes
Downloads
- Datasheet REFU 261 – REFU 261German, As of 11/2026, Version vorläufig, PDF, 1.2 MB
Discuss your project
Which model suits your storage project? We advise you personally, directly with our engineers.
Or directly+49 7121 145 1888info@refu.com
Request a project