WES-125/261 · TECHNICAL SPECIFICATION

125/261 kWh Liquid-Cooled C&I Energy Storage System

One cabinet integrates a 261 kWh LiFePO4 battery and a 125 kW PCS, with full liquid cooling and optional PACK-level fire protection. Plug-and-play and expandable on demand, it serves peak shaving, microgrids and backup power for commercial and industrial users.

LiFePO4 cells 3.2 V / 314 Ah Full liquid cooling · ΔT within a cluster ≤3 °C PACK-level fire protection (optional) Ethernet · Modbus-TCP monitoring

261kWh Rated capacity

125kW Rated power

≥88% System Cycle Efficiency

≤100ms Charge/Discharge Conversion Time

Product Overview

System Overview

Standard distributed cabinet design: battery, inverter, AC protection, energy management, thermal control and monitoring are highly integrated. Modular construction is plug-and-play with a short installation period, and standard modules combine for capacity expansion on demand.

System

Integrated Cabinet

INTEGRATED CABINET

261 kWh battery, 125 kW PCS, metering, monitoring, fire protection and liquid cooling in one cabinet — ready to run once installed.

Dimensions W×D×H 1340×980×2590mm

Weight Approx. 2.5 t

Battery

LFP Battery System

LFP BATTERY SYSTEM

314 Ah high-capacity cells in 1P260S configuration: high safety, long life, 261.248 kWh total energy.

Rated capacity 261kWh

PACK configuration 1P260S

Inverter

125 kW PCS

PCS CONVERTER

Three-level design with constant-voltage, constant-current and constant-power modes, up to 98.5% efficiency, grid-tied and off-grid operation.

Rated power 125kW

Max. efficiency 98.5%

Control

BMS + EMS

BATTERY & ENERGY MGMT

Two-level BMS (1×BCU + 5×BMU) and modular EMS strategies keep the whole charge/discharge process under control.

Battery management 1×BCU + 5×BMU

Protocol Modbus-TCP

Thermal

Full Liquid Cooling

LIQUID COOLING

Zoned cooling with independent circuits; the inverter-driven liquid cooling unit keeps cell temperature within 35 °C.

Cell temperature ≤35℃

Cell ΔT ≤3℃

Fire

PACK-level fire protection (optional)

FIRE PROTECTION

Perfluorohexanone extinguishing agent with two selectable schemes; please specify when ordering.

Extinguishing agent Perfluorohexanone

Protection level PACK level

System Scheme

System Scheme

The WES-125/261 integrates an independent 261 kWh energy storage system: an all-LiFePO4 battery bank built from one 125 kW PCS and 261 kWh of battery capacity. High energy and long charge/discharge capability meet long-duration peak-shaving requirements.

001

01 INTEGRATED

All-in-One Cabinet Solution

Integrated Cabinet Design

The cabinet integrates a 261 kWh battery system (modules, boxes, racks, high-voltage box and a two-level BMS), a 125 kW PCS, an energy metering unit, monitoring, fire protection and a liquid cooling system.

Model WES-125/261

Capacity 261kWh

Power 125kW

Connection Three-phase three-wire

Battery system 314 Ah LiFePO4 cells, 1P260S, 261.248 kWh total
Energy storage converter 125 kW PCS (three bridge arms), bidirectional AC/DC conversion
Energy management EMS controller + station control software
Auxiliary systems Metering, monitoring, fire protection, 5 kW cooling unit and piping

Figure 2 · System structure composition

002

Figure 1 · System block diagram

02 TOPOLOGY

Bidirectional Conversion · Grid-tied & Off-grid

Bidirectional Conversion

The PCS uses a three-phase three-bridge-arm topology with single-phase and three-phase active/reactive power control and multi-unit parallel expansion. Communication with the BMS and EMS enables power regulation and charge/discharge management.

Operating mode Grid-tied / off-grid dual-mode operation
Power regulation Adjustable active/reactive power, PF -0.99/-1 to 1
Transfer speed Charge/discharge transfer ≤100 ms
Safety protection Anti-islanding, AC/DC disconnection and DC reverse-connection protection

Key Specifications

Key Specifications

Model WES-125/261

Cell type 3.2 V/314 Ah LiFePO4

Rated capacity 261kWh

Rated DC voltage 832V

Battery voltage range 650Vdc 1000Vdc

Max. DC current 198A

Battery PACK configuration 1P260S

Allowed C-rate ≤0.5P

Rated power 125kW

AC connection Three-phase three-wire

Overload capability 1.1× for 10 min · 1.2× for 1 min

Rated grid voltage AC380V 304V 437V

Rated grid frequency 50Hz 47.5Hz 52.5Hz

Rated output current 180A

Power factor -0.99/-1～1

Charge/discharge transfer time ≤100ms

System cycle efficiency ≥88% (at rated conditions)

Cooling method Liquid cooling unit

Fire protection (optional) Perfluorohexanone at PACK level · Scheme 1 / Scheme 2

Allowed relative humidity 0–95%, non-condensing

Dimensions (W×D×H) 1340×980×2590mm

Weight Approx. 2.5 t

Communication / protocol Ethernet · Modbus-TCP

Battery System & PCS

Battery System & PCS

High-safety, long-life large-capacity LFP cells paired with an efficient three-level PCS: battery clusters work fully independently to avoid circulating current, while BMS and EMS manage the whole charge/discharge process.

003

03 LFP CELL

High-Safety Long-Life LFP Cells

3.2V / 314Ah LiFePO4

Cell dimensions 173.7×71.7×204.6 mm (L×W×H), weight about 5.60 kg. Battery box: 166.4 V, 314 Ah, 52.249 kWh, about 341.5 kg.

Cathode material LiFePO4, charge cut-off 3.65 V
Discharge cut-off 2.5V 0℃≤T≤55℃ · 2.0V -20℃≤T 0℃
DC internal resistance 0.18±0.05mΩ
Operating environment Charging 0–60 °C · Discharging -30–60 °C

Nominal capacity / voltage 314Ah · 3.2V

Standard charge/discharge current 0.5C 25±2℃

Max. continuous current 0.5P 25±2℃

DC internal resistance (DCIR) 0.18±0.05mΩ

Cell weight 5.60±0.3kg

Figure 4 · Battery box

004

WES-125/261 · Integrated cabinet

04 PCS 125kW

125 kW Three-Level PCS

Three-level Topology · 98.5% Efficiency

Built on 100 kW modules with a three-level design, the PCS offers constant-voltage, constant-current and constant-power modes; zero battery consumption on standby, ≤100 ms transfer time and up to 98.5% efficiency.

Battery-friendly Clusters operate fully independently, avoiding circulating current and extending service life
Flexible application Compatible with three-phase three-wire/four-wire systems; the communication bus monitors every module
Scalability Multi-unit parallel operation for easy expansion
Grid support L/HVRT, active and reactive power control

Rated output power 125 kW · max. 137.5 kVA

Operating voltage range 615V–950V

Max. current 198A

Power factor 0.99 (1 leading to 1 lagging)

Current distortion <2%（额定功率）

Overload capability 110% (continuous)

Operating temperature -30 °C to 55 °C (derating above 45 °C)

Max. altitude 4000 m (derating above 2000 m)

Protection / cooling IP20 · intelligent air cooling

Communication interface CAN / RS485 / Ethernet

Liquid Cooling & Fire Protection

Thermal Management & Fire Protection

The pack liquid-cooling system uses zoned cooling, each zone with its own circuit, ensuring even pack temperature and higher pack efficiency; fire protection is offered in two PACK-level schemes (optional).

35℃

Cell temperature control Cell Temperature

Thermal management keeps cells within 35 °C for optimum operation.

3℃

Cell ΔT Cell ΔT

Cell ΔT within a cluster stays below 3 °C for better consistency and longer life.

5kW

Inverter-driven cooling unit Liquid Cooling Unit

Cooling output adapts on demand, balancing temperature accuracy and energy use.

2schemes

Fire schemes Fire Schemes

Two PACK-level perfluorohexanone schemes; please specify when ordering.

005

05 THERMAL

Zoned Liquid Cooling · All-Weather Control

Zoned Liquid Cooling

The thermal system consists of one inverter-driven liquid cooling unit and its piping: when cells run hot, cooler medium is supplied to remove heat; when too cold, warmer medium raises cell temperature, keeping cells in their optimum range.

Zoned cooling Modules are divided into multiple independent cooling zones
Independent circuits Each zone has its own coolant loop for tighter control
Variable frequency Cooling delivered on demand to save energy
Uniform temperature Even temperature across the whole pack

Figure 10 · Liquid cooling system

Fire Scheme 1 · With Host Detection

SCHEME 1 · WITH HOST DETECTION

A five-in-one detector monitors H₂/CO/VOC concentration, smoke and temperature, triggering a non-pressurized perfluorohexanone unit that suppresses fire through piping and nozzles.

Detection H₂ · CO · VOC · smoke · temperature

Extinguishing agent Perfluorohexanone (non-pressurized)

Fire Scheme 2 · Independent Type

SCHEME 2 · INDEPENDENT TYPE

Independent perfluorohexanone inside the PACK protects the modules; during thermal runaway it spreads across the enclosure faster and isolates air — safer, cleaner and more efficient than alkane or water-based agents.

Installation Independent type inside PACK

Extinguishing agent Liquid perfluorohexanone

Application Scenarios

Application Fields

One cabinet, many uses: from C&I peak shaving to microgrids and backup power; standard modules combine on demand for varied load profiles.

Factories & Enterprises Fluctuating loads · peak shaving

Microgrids Grid/off-grid switching · dispatch

Renewable Plants Distributed energy access

Business Centers Demand control · tariff arbitrage

Temporary Outdoor Loads Large temporary load centers

Emergency Power Emergency response · backup

Standards

EXECUTED STANDARDS

GB/T 36276 Li-ion cells for power storage GB 51048 Design code for ESS stations Q/GDW 10769 Technical guide for ESS stations GB 7251 LV switchgear assemblies GB 50217 Cable design for power projects GB 51309 Fire emergency lighting DL/T 527 Static relay protection GB/T 2423 Environmental testing

Supply List

SUPPLY LIST

Battery box 314 Ah · 1P260S · 261.248 kWh HV box 1000 V / 250 A BMS (BMU + BCU + harness) 125 kW PCS (three bridge arms) EMS controller + station software 5 kW cooling unit + piping Fire protection (optional · scheme 1/2) Smart cabinet (with distribution parts)

Installation & Selection

Installation & Selection

Ready to deploy: a pre-cast base, reserved service clearance, proper cable routing and fire sealing complete the installation; inspect weekly, monthly and seasonally after handover.

Base BASE

Concrete / channel steel · 200 mm high

Length and width not smaller than the cabinetVertical inclination ≤5%

Clearance CLEARANCE

Sides ≥800 mm · Front ≥1000 mm

Rear ≥100 mmService space on all sides

Cable laying CABLE LAYING

Bottom entry · trench 400 mm deep

Power and signal cables ≥0.1 m apartOutdoors: cable trench + conduit burial

Fire sealing FIRE SEALING

Seal cable entries with fireproof putty

Thickness must exceed 20 mmPoor sealing causes condensation and shortens component life

Maintenance MAINTENANCE

Daily care · periodic inspection

Weekly / monthly / seasonalCabinet, cooling unit, modules and fire system checked

Commissioning COMMISSIONING

Performed by trained personnel

Confirm grounding and insulation before power-onNotify our technicians to support commissioning

Make Every Kilowatt-Hour Count

WOLUN LIQUID-COOLED ENERGY STORAGE

The 125/261 kWh liquid-cooled ESS builds in peak shaving, demand control, anti-backflow and backup strategies. Contact us for a system design and quotation.

Sichuan Wolun Electric Co., Ltd. SICHUAN WOLUN ELECTRIC CO., LTD.

A wind-solar-storage-charging integrated energy system provider — an industrial, integrated, high-tech group.

Address

WOLUN New Energy Group Co., Ltd.: Room 2602, 26F, Unit 1, Building 5, No. 8 Liuli Road, Jinjiang District, Chengdu, Sichuan
Sichuan Wolun Electric Manufacturing Co., Ltd.: No. 108 Tianyuan Street, Xinmin Town, Da'an District, Zigong, Sichuan

Contact

Group hotline: +86 028-68938363
Factory hotline: +86 0813-5308858
Domestic sales: +86 188 2888 5368
Domestic e-mail: wolunxs@wolungroup.com
Overseas sales: +86 188 2888 5328
Overseas e-mail: wolunhw@wolungroup.com
Aftersales: 400 604 1668