HomeTechnical notes › BESS Cabinet Layout: How Battery Clusters, PCS, BMS and Fire Suppression Are Arranged by Layer

05 Informational content / Technical articles 2026-09-27 Published ~ 11 min read GB/T 36276 · GB/T 36558

BESS cabinet layout
How battery clusters / PCS / BMS / fire suppression are arranged by layer

A BESS cabinet looks like a shipping container, but inside it is divided into 5 layers — battery clusters / BMS / PCS / fire suppression / thermal management, and each layer has its own code requirements and protection provisions.This article covers GB/T 36276-2018, Lithium-ion Batteries for Energy Storage and GB/T 36558-2018, Lithium-ion Battery Cabinets for Electrical Energy Storage, a breakdown of the BESS cabinet's 5-layer structure, the core components in each layer and typical layouts, with 4 workshop photos and 5 common Q&As.Zhejiang Golden Unicorn builds BESS cabinet enclosures · MOQ 1 unit · 15–25 days.

1. Where the BESS cabinet sits in the new power system The "storage" in source / grid / load / storage

A BESS cabinet (Battery Energy Storage System) is akey supporting elementof the new power system. Typical applications:

  1. Commercial and industrial peak shaving: discharge during the plant's peak demand periods, charge during off-peak periods, cutting electricity costs
  2. Co-located storage with renewables: storage paired with solar PV / wind output to smooth the generation curve
  3. Grid frequency regulation and peak shaving: standalone storage stations that help stabilize the grid
  4. Microgrids / islands / border outposts: off-grid storage providing an independent power supply

Zhejiang Golden Unicorn suppliesBESS cabinet enclosure fabrication(that is, the 5-layer structure's enclosure / frame / cable routing / ventilation). Core components such as batteries / BMS / PCS can be supplied by specialist battery or converter manufacturers, or supplied by the customer.

2. The BESS cabinet's 5-layer structure From the inside out: battery → management → conversion → fire suppression → thermal management

LayerFunctionCore componentsScope of supply by Golden Unicorn
Layer 1: Battery clusterStores electrical energyLFP cells + modulesCabinet frame (no battery connection)
Layer 2: BMSMonitors every cellBattery management system + displayIn-cabinet wiring / communication cable
Layer 3: PCSDC ↔ ACPower conversion systemPCS mounting position + heat dissipation channel
Layer 4: Fire suppressionExtinguishing + alarmGas suppression / perfluorohexanone / water mistFire suppression piping reserved + trigger signal cable
Layer 5: Thermal managementTemperature control 15–35°CAir conditioner / liquid cooling / forced air coolingVent + air conditioner position + liquid cooling interface
Important notice

Golden Unicorn handles BESS cabinet fabrication (frame / wiring / ventilation / cabinet door) and does not directly manufacture batteries, battery management systems, or converters. The battery / BMS / PCS for the complete cabinet are supplied by battery plants / converter manufacturers with the corresponding qualifications, and Golden Unicorn is responsible for assembly integration and cabinet fabrication.

3. Battery cluster (innermost layer): cells + modules The "core" of a BESS cabinet

The battery cluster is thecore of a BESS cabinet. Typical configuration:

  1. Cell: lithium iron phosphate (LFP) cell, commonly 280Ah / 314Ah
  2. Module: 16–24 cells connected in series form 1 module, voltage 50–80V
  3. Battery cluster: 8–16 modules connected in series, voltage 600–1500V (high-voltage DC)
  4. Battery pack: multiple battery clusters connected in parallel, capacities of 215 kWh / 344 kWh / 430 kWh are common

Golden Unicorndoes not directly manufacture cells, but handles cell module rack fabrication (frame / fasteners / vibration dampers).

4. BMS: Monitoring + Protection The "brain" of the battery

The BMS (Battery Management System) handles:

  1. Real-time monitoring: voltage / current / temperature of each cell, sampling rate above 1 Hz
  2. SOC estimation: remaining capacity percentage, accuracy ±3%
  3. Protection: overvoltage / undervoltage / overcurrent / overtemperature / short circuit — trips the main circuit when triggered
  4. Balancing: active balancing when cells drift apart, extending service life
  5. Communication: uploads to SCADA / EMS via RS485 / CAN / Ethernet

Zhejiang Golden Unicorn provides the BMS mounting position, communication cable tray and display panel; the BMS itself is supplied by the battery manufacturer.

5. PCS: DC ↔ AC The "interpreter" between the battery and the grid

The PCS (Power Conversion System) handlesconversion between DC and AC:

  1. Charging: AC → DC (grid / PV power stored in the battery)
  2. Discharging: DC → AC (battery power delivered to the grid / load)

Common PCS brands: Huawei / Sungrow / Kehua / TBEA / Sineng / SMA, etc.; 50–250 kW is the usual power range. Zhejiang Golden Unicorn provides the PCS mounting position and cooling path.

6. Fire Suppression / Thermal Management: Mandatory, Not Optional Required by GB/T 36276 + GB/T 36558

In a BESS cabinet,fire suppression + thermal management are mandatory, and missing either one fails acceptance:

ItemRequirementZhejiang Golden Unicorn supplies
Fire suppressionClean agent (perfluorohexanone / heptafluoropropane) / water mist / heat + smoke + gas detectionReserved fire suppression piping + trigger signal wiring + ventilation openings
Thermal managementAir conditioning (5 kW / 10 kW cabinet units) / liquid cooling (glycol + water) / forced air coolingAC unit position + ventilation openings + liquid cooling inlet/outlet pipe connections
Access controlWith electromagnetic lock, interlocked on faultDoor contact + electromagnetic lock wiring
EmergencyEmergency lighting + exit signageLED emergency light position
Important

Fire suppression + thermal management for BESS cabinetsmust be provided by a specialist contractor licensed for fire protection / HVAC, while Golden Unicorn handles the cabinet's reserved interfaces and mounting provisions.

7. Factory Photos: 4 Shots of BESS Cabinet Fabrication (shop floor photos)

GU ELECTRIC cabinet exterior as shipped (factory floor photo)
Figure 1 — Cabinet and door exterior (with touchscreen and indicator lights)enclosure-shell-fabrication · shop floor photo
Component layout and secondary wiring inside the cabinet (factory floor photo)
Figure 2 — Component layout and secondary wiring inside the cabinet (shop floor photo)cabinet-assembly-workshop · factory floor photo
Busbar and cabinet fabrication detail (factory floor photo)
Figure 3 — Copper busbar with tin platingbusbar-fabrication-and-bending · workshop photo
N184Photo ・ Pending
Photo 4 — Pre-shipment testing: enclosure sealing / ventilation / fire suppression / liquid cooling interfaces inspected item by item.inspection-and-commissioning · factory floor photo

FAQ FAQ

Can Golden Unicorn build complete BESS cabinets in-house?

Golden UnicornWe take on BESS cabinet fabrication (frame / wiring / ventilation / doors) and assembled integration. The battery, battery management system (BMS) and power conversion system (PCS) for the complete unit are supplied by specialist manufacturers with the relevant qualifications, with Golden Unicorn coordinating the interface. MOQ 1 unit, 15–25 days.

What IP rating does a BESS cabinet need?

Outdoor container-type BESS cabinets start at IP55(GB/T 4208), with IP67 inside the battery pack. Golden Unicorn supplies IP55 outdoor as standard, with IP65 available at extra cost.

Does a BESS cabinet need liquid cooling?

High-power units (> 250 kW) require liquid cooling;low-power units (≤ 100 kW) are fine with air cooling / air conditioning. Liquid cooling costs 20–30% more but dissipates heat 2–3 times better, making it suitable for frequent charge/discharge duty.

How does a BESS cabinet relate to an EV charging station distribution cabinet?

They are different equipment.A BESS cabinet isa battery pack + power conversion system, responsible for storing electrical energy; an EV charging station distribution cabinet handlespower distribution for the charging stations, responsible for delivering power to the chargers. A charging site mayhave both BESS cabinets and EV charging station distribution cabinets, the former for energy storage and peak shaving, the latter to feed the chargers.

Does a BESS cabinet need 3C / UL9540A certification?

3C is not yet mandatory for BESS cabinets in China(some provinces require CQC); it depends on project requirements. North American projects require a UL9540A test report(provided by the battery manufacturer or a certification body). Golden Unicorn cancoordinate the processwork with certified partners.

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