344kWh Battery Storage Cabinet (eFLEX BESS) - AceOn Group
eFLEX BESS Technology

344kWh Battery Storage Cabinet (eFLEX BESS)

AceOn offer a liquid cooled 344kWh battery cabinet solution. The ultra safe Lithium Ion Phosphate (LFP) battery cabinet can be connected in parallel to a maximum of 12 cabinets therefore offering a 4.13MWh battery block. The battery energy storage cabinet solutions offer the most flexible deployment of battery systems on the market.

Capacity
344kWh
Chemistry
LFP (Ultra Safe)
Cooling
Liquid Cooled
Max Cabinets
12 Units
Maximum Scalability
System Capacity Range
344kWh → 4.13MWh
344kWh eFLEX BESS Cabinet Exterior 344kWh eFLEX BESS Cabinet Interior Components
Capacity: 344kWh
Voltage: 1228.8V
Chemistry: LiFePO₄
Cooling: Liquid
344kWh eFLEX BESS Technical Specifications
Detailed Specifications

Technical Specifications

Complete technical details and specifications for the 344kWh eFLEX BESS Liquid Cooled Battery Cabinet system.

Parameter Specification
System Information
System Model BESS-MSI-7605.5 | BESS-MSI-7605
Max. Power 172kW | 344kW
Nameplate Energy 344kWh
Battery Information
Battery Chemistry LFP
Capacity 280Ah
Configuration 384S1P
Nominal Voltage 1228.8V
Voltage Range 1075.2-1382.4V
Working Conditions
Degree of Protection NEMA 3R / IP55
Noise Emission ~75dB@1M
Operating Temperature Range -22°F~122°F / -30°C~50°C
Relative Humidity 0~95% (No condensing)
Max. Working Altitude 6,500ft/2,000m
General Information
Dimensions(W×H×D) 1300×2460×1300mm
Weight 3,500kg
Cooling Method Liquid Cooling
Fire Suppression System Aerosol
Certificate IEC62619, UL1973, UL9540A
Complete Documentation

Download Full Datasheet

Get the complete technical documentation including detailed drawings, installation guidelines, and performance specifications.

Download Complete Datasheet PDF →
344kWh Battery Scalability Showcase
Enterprise Scalability

Maximum System Flexibility

System Capacity Range
344kWh → 4.13MWh
Scale from single cabinet to enterprise-level energy storage

344kWh battery cabinet can be connected together in blocks of 12 with a Battery Connection Panel to create a 4.13MWh Battery Block which connects to a PCS or Inverter

344kWh Battery Cabinets Connected in Scalable Configuration
Single Unit: 344kWh
Max System: 4.13MWh
Multiple 344kWh cabinets deployed in enterprise configuration with Battery Connection Panel integration
Advanced LFP Battery Cell Technology
Advanced Cell Technology

Battery Cell

LFP Chemistry
Prismatic Cell Specifications
3.2V 280Ah
High-power performance with industry-leading safety and low cost

AceOn's battery storage systems rely on advanced LFP chemistry to provide a combination of high-power performance, low cost, and industry-leading safety. Flexible configuration to serve application scenarios, 3.2V 280Ah prismatic cells became AceOn's best pick for a battery storage solution.

Advanced Features

Advanced features of cells are:

Enhanced Safety Profile
Lower fire risk, no explosion risk, higher safety
Advanced Thermal Design
Advanced thermal design
Active Protection Systems
Active protection: short circuit, over-charging, over-discharging, high temperature, extrusion, and other safety features
Safety Vent Design
Safety Vent (in the middle of 2 pole of cell)
Corrosion Protection
Metal protected against corrosion, be made of aluminum
Self-Discharge Rate
Self-discharge rate:Per month ≤3.0%
Battery Module Modular Architecture
Modular Architecture

Battery Module

Customised Configurations

Flexible design allowing for tailored system configurations

Ease of Maintenance

Simplified serviceability and component accessibility

Future Expansion

Scalable architecture for growing energy requirements

Modular System Architecture

Modular design which allows for customized configurations, ease of maintenance, and future expansion capability. Modules are formed by configuring 48 of LFP cells in series connection. Modules connected with a battery management system (BMU) to form a rack-mountable module assembly. Multiple module assemblies are then combined into a rack. Each rack contains rack-level BMS.

Interface Design

Connection & Safety Features

The positive and negative interface of the battery modules are provided with obvious marks, are convenient to connect, visual check, examine and repair; The positive sign of the battery module is "+" and the negative sign is "-". The external contact surface of the battery module is covered by insulating material(Metal protected against corrosion, the top cover is made of PP, the bottom is made of aluminum), the copper bar and screws are connected internally to prevent short circuit to ensure the electrical safety of the battery module. Each battery module has 16 temperature detectors.

Module Specifications

Cell Configuration
48 LFP cells in series connection
Rack-mountable module assembly design
BMU (Battery Management Unit) integration
Interface Specifications
Obvious positive "+" and negative "-" markings
Convenient connection and visual inspection
Easy examination and repair access
Safety & Materials
Top cover: PP (Polypropylene)
Bottom: Aluminum construction
Internal copper bar and screw connections
Short circuit prevention design
Corrosion-resistant metal protection
Temperature Monitoring
16
Temperature Detectors per Module
Battery Rack System Configuration
System Integration

Battery Rack

There are 9 slots in each battery rack to accommodate 8 modules and 1 BSPU (Battery Switch & Protective Unit). Racks are connected in parallel and paired with a system BMS to meet the power and energy requirements of the application at hand. All wire connections are placed on the front side of the rack to allow for easy installation and maintenance.

Complete Integration

Comprehensive System Components

Each battery Rack is with 384 battery cells in series with switch-disconnector, contactor, detective unit, sampling line, battery management systems, control unit, etc.

9
Slots per Rack
384
Battery Cells
1
BSPU Unit
Battery Management System Architecture
Intelligent Control

Battery Management System

Each battery Rack is with 384 battery cells in series with switch-disconnector, contactor, detective unit, sampling line, battery management systems, control unit, etc.

Module Battery management unit (BMU)

Cell-level voltage and temperature detection with balance functions

Rack Battery Management controlling System (RBMS)

Manages all module BMS units and executes protection functions

System-level BMS (SBMS)

Manages rack BMS units and communicates with PCS or EMS

At the lower level is the Module BMS (BMU), which is designed to detect voltage, temperature, and execute cell balance functions for cells. The rack BMS (RBMS) can manage all module BMS units and detects total voltage, current, and executes protection functions by switching DC-contactor. Finally, a system-level BMS (SBMS) manages rack BMS units and communicates with PCS or EMS. The table below outlines BMS units of the system.

Architecture of System BMS

Architecture of System BMS - Complete system diagram showing SBMS, PCS, BCP, RBMS, BMU and module connections

BMS Functionality

FUNCTIONALITY BMU RBMS SBMS
Measurement
Cell Voltage
Cell Temperature
Rack Voltage
Rack Current
Calculation
SOC
SOH
Contactor Control
Control
Cell Balancing
Communication
CAN2.0
RS485
Ethernet
Battery Connection Panel - Critical BESS Equipment
Critical BESS Equipment

Battery Connection Panel

Battery Connection Panel (BCP) is a piece of crucial equipment in our BESS design. It serves several functions in the system:

BCP System Functions

1

Battery Combiner

The main function of the BCP is to combine multiple racks of batteries to one DC bus, then connect to the DC input of PCS with necessary protections. With SPDs, the BCP serves as a key part of battery protections.

2

Auxiliary Power Supply

With input connections, switches, connectors, UPS, and auxiliary power connection to the auxiliary loads (BMS, module fans, HVAC, FSS, etc.), BCP as acting as an auxiliary power panel to power internal equipment.

3

Communication Combiner

Through the connections to the BMS, HVAC, FSS, and other internal equipment, then combine them to the System Controller for control integration, the BCP also serves as a communication combiner and sometimes as a protocol adaptor.

AceOn Battery Connection Panel - Critical BESS equipment for power distribution and system integration

Battery Connection Panel

Multi-Function Integration

BCP Core Capabilities

Battery Combiner
Auxiliary Power
Communication Hub
Battery System Controller - Universal BESS Interface
Universal Integration

Battery System Controller

To offer a universal interface for communication between battery systems and SCADA or EMS and release EMS from basic system protection, AceOn deploys a system controller as part of the BESS integration.

Control Integration

Control integration of the battery system (include battery BMS, cooling units, BCP, PCS etc.)

Universal Interface

Offer a universal interface for communication between battery systems and SCADA or EMS.

Communication Support

Supports RS-485, CAN, dry contact, Ethernet communication and easy integration

Data Logging

Data logging (short period) for trouble shooting

Remote Firmware Update

Remote firmware updating

Specification of Battery System Controller

ITEM SPECIFICATION
Power Supply DC 12~24V
Total Power Consumption < 25W
Processor Cortex-A53
Frequency 1.1GHz
M.2 SSD 1 channel, 256GB
Operating System Ubuntu-20.04
RS485 8 channels, baud rate 1200bit/s, 2400bit/s,
4800bit/s, 9600bit/s, 19200bit/s, 38400bit/s,
115200bit/s
RS232 3 channels, baud rate 1200bit/s, 2400bit/s,
4800bit/s, 9600bit/s, 19200bit/s, 38400bit/s,
115200bit/s
Ethernet 4 channels 1000M adaptive
CAN 3 channels
TF Card Interface 1 channel
USB Host 2 channels
State Input 18 channels, Input circuit adopts opt coupler
isolation
Passive Dry Contact 8 channels, Output circuit adopts relay isolation
RTC Clock Yes
Independent Hardware Watchdog Yes
Communication Protocol Modbus-RTU, Modbus-TCP
Operating Temperature Range -30°C ~ +60°C
Dimensions (W×H×D) (mm) 232×59×113.2
Relative Humidity 0~65% (noncondensing)
Cooling Concept Natural Air
Installation Method Wall mount or rail mount
Liquid Cooling System - Advanced Thermal Management
Advanced Thermal Management

Liquid Cooling System

The liquid cooling system is small in size and equipped on each rack.

Advantages of Liquid Cooling

Performance Icon

Higher cooling capability

compare to air cooling, liquid cooling is capable of taking more heat away from batteries under the same condition. And liquid cooling is the best choice when thermal density is beyond the capability of air cooling.

Temperature Icon

Better temperature uniformity

Cooling liquid has a specific heat capacity which leads to a smaller temperature rise during the cooling process. Therefore, battery cells will have a smaller temperature difference with liquid cooling.

Maintenance Icon

Lower Noise Emission

Without fans on battery modules for air cooling means no noise emission from battery modules.

Fire suppression system for liquid cooling battery energy storage showing advanced safety features and thermal management

Working principle of Liquid Cooling

Working principle of Liquid Cooling

1

Battery Cooling

Cooling liquid powered by the pump will circulate inside battery modules and take the heat from batteries. When the liquid gets out of the battery modules, it became hot liquid with the heat from batteries. The hot liquid will circle back to a heat exchanging tank.

2

Heat Exchanging

Inside the heat exchange tank, the refrigerant will vaporize from liquid state to gaseous state. During this state/phase change process, the refrigerant will absorb a huge amount of heat from the battery cooling liquid and cool down the cooling liquid.

3

AC Cooling

The rest of the system is a standard Air Conditioner which releases the heat to the environment through the phase change of the refrigerant.

Fire Suppression and Detection System - Advanced Safety Protection
Advanced Safety Protection

Fire Suppression and Detection System

Type of Fire Protection

The outdoor cabinet has a separate and relatively sealed space. According to the working principle of the energy storage system and other related technical characteristics, aerosol fire extinguishers and smoke detectors are installed. The fire extinguisher will automatically release aerosols and send a signal to the control panel when the internal temperature reaches 74 °C (162 °F). After releasing, the pressure sensor will send a signal to the Fire Control Panel to report the release event. In a separate loop, the smoke detector sends a signal to the control panel after sensing smoke. Smoke detection is normally reported before aerosol release. Upon receipt of either signal, the fire control panel sends an alarm to the fire mainframe and triggers a light and sound alarm.

Fire suppression system flow diagram showing thermal bulb, smoke detector, control panel, and extinguishing process

Fire suppression system

Detection Components

Thermal Bulb: Activates at 74°C (162°F)
Smoke Detector: Early warning system
Pressure Sensor: Confirms aerosol release

Control Integration

Control Panel: Central monitoring hub
Fire Mainframe: System coordination
Strobe and Horn: Visual and audible alerts

Suppression Process

Open Actuator: Initiates release mechanism
Release: Aerosol deployment
Extinguishing: Fire suppression completion

Advanced Technology

Aerosol automatic fire extinguishers

When the temperature rises high enough, the extinguisher will automatically and efficiently generate and release an ultra-fine potassium-based aerosol with the assistance of a series of auxiliary components. With the collaboration of the patented design, the aerosol composition, and the ultra-fine particle size, the reaction between oxygen and combustible materials is greatly interrupted, thus ending the spread of flame. Compared to gas fire extinguishing systems, aerosol offers higher performance than gas while using the same weight of the agent. Aerosol extinguishers require no pressurized vessels, pipes or other expensive components, are almost maintenance-free, have a service life of over ten years, and have a minimal size and weight. All these advantages make aerosol fire extinguishers a highly cost-effective solution for fire prevention.

Fire Protection Icon

Higher Performance

Superior effectiveness compared to gas systems using same agent weight

Maintenance Icon

Low Maintenance

Almost maintenance-free with 10+ year service life

Cost Effective Icon

Cost-Effective

No pressurized vessels or expensive components required