A cell approaches its charge limit, a temperature sensor lead opens, or insulation resistance falls. Can the battery management system detect the condition, issue the correct command and confirm that the protection action has taken place? For 800V electric vehicles and high voltage battery energy storage systems, these questions require repeatable inputs and measurable results.

Cell emulation gives engineers control over individual cell voltages, imbalance and selected fault conditions. Combined with temperature, insulation, current and communication resources, it supports verification of BMS measurement and control logic. Physical battery tests and system safety assessments complete the evidence needed for the intended application.

Higher voltage makes the verification task more demanding

For a given cell chemistry, higher pack voltage usually requires more cells in series. The term 800V does not define a fixed cell count: the actual configuration depends on cell voltage and the pack operating range. More channels and higher common mode voltage place additional demands on isolation, wiring and consistent measurement across the stack.

Automotive validation emphasizes charging behavior, vehicle integration and fault response. Stationary storage adds sustained operation, multiple battery strings and coordination with the power conversion system (PCS) and supervisory controls. A bench that reproduces these inputs helps engineers compare hardware and software versions under the same conditions.

Why real cells and cell emulation belong in the same test program

Real cells bring state of charge, temperature and aging into every test. These factors are essential to battery validation, but they also change the starting conditions. A simulator can reproduce a threshold crossing or channel imbalance without first charging, discharging or conditioning a physical pack. Engineers can use that repeatability to isolate sampling errors, check diagnostic boundaries and reproduce failures during regression testing.

Four practical verification scenarios

Measurement accuracy and channel consistency

Apply the same known voltage to each channel, compare BMS readings and sweep the operating range in small steps near protection thresholds. Record the input reference, reported value, sampling interval and uncertainty. Resistance simulation checks the temperature sensing input; chamber testing separately evaluates the hardware under actual temperature exposure.

Fault detection and protection execution

Ramp one channel toward a limit or inject a voltage step and sensing circuit fault. Capture detection, alarm level, command, contactor feedback and PCS response on a common time reference. This reveals whether the BMS completes the protection sequence and recovers as intended. A fault at the sensing interface validates control logic; high energy short circuit and thermal runaway tests require the applicable battery safety procedures.

Balancing and state estimation

Set different channel voltages or model parameters to create deliberate cell imbalance, then observe balancing enable conditions, current and strategy changes. State of charge (SOC) and state of energy (SOE) verification also need current inputs, a capacity or energy reference and dynamic profiles. Static voltage outputs alone cannot establish estimator accuracy, and an SOC result cannot substitute for an SOE requirement.

Ripple response and closed loop testing

Controlled ripple helps evaluate the cell measurement front end, filtering and diagnostic stability. IT2600 can superimpose voltage ripple from 1 to 1000 Hz, up to 100 mVpp. Engineers should match this range to the target disturbance. Cell input ripple tests, auxiliary supply port tests and full electromagnetic compatibility (EMC) tests use different ports and procedures.

In a hardware in the loop (HIL) setup, the cell simulator acts as an output resource alongside a real time model, DUT communication and acquisition. Channel synchronization and closed loop timing are verified in the integrated setup.

An ITECH hardware platform from cells to modules and packs

All core electrical simulation and supply functions in an ITS5800 BMS test setup can be implemented with ITECH hardware. The platform combines cell, temperature and insulation simulation with module or pack voltage inputs, current measurement validation and auxiliary power. Each resource is selected for the DUT interface and required operating range.

IT2600 integrates eight isolated channels in a 1U instrument for 0 to 6 V cell input verification. Multiple units can form configurations with more than 200 channels and series operation up to 1200 VDC within the rated system conditions. Independent channel control, source and sink current capability, battery models and open circuit, short circuit and reverse polarity simulation provide controllable inputs for sampling, balancing and diagnostic tests.

Figure 1. An example BMS and CMU verification configuration using ITECH hardware. The low voltage, high current IT-M3900C model shown serves current sampling validation; module and pack voltage resources are selected separately, including IT6000C where required.

Dedicated ITECH DC resources extend the setup to module and pack voltage and current inputs. IT6000C and IT-M3900C provide bidirectional sourcing and sinking; IT-M3100 supplies programmable voltage inputs for suitable ranges. Selecting resources by DUT interface and test requirement connects cell sensing verification with the wider BMS electrical architecture. [16–18]

IT-N6300 provides three independently controlled auxiliary supply outputs. ITS5800 coordinates these resources with DUT communication and digital I/O. Match model ratings, isolation, accuracy and timing to the test procedure and current sensing path. Temperature and insulation input simulation verifies detection logic, while environmental and dielectric withstand tests use separate procedures. [19]

Chinese storage requirements provide measurable bench targets

GB/T 34131-2023 addresses battery management systems for electrical energy storage. Clause 7.2.2 lists battery simulation equipment, and normative Annex B specifies its requirements. The examples below show how BMS functions translate into observable bench results. These are Chinese standard requirements, not IEC or UL limits. [1]

Timing must start at the event specified by the standard. Fault injection to alarm, alarm to command and command to physical action are different intervals. Annex B specifies ranges including 0 to 15 V for cell simulation and 0 to 2000 V for string simulation. Equipment is selected across the ITECH portfolio to match the required range, accuracy, isolation and test conditions. For example, IT6000C includes models up to 2250 V for high voltage string or pack tasks; cell inputs are configured separately. Verify the complete setup against the apparatus and measurement requirements, including calibrated measurement uncertainty. [1, 16]

International standards cover different levels of the system

For international projects, select requirements by the product being evaluated and the destination market. IEC and ISO documents are standards; UL and CSA documents support regional product assessment; NFPA 855 addresses installation safety. UN Regulation No. 100 is a vehicle approval regulation in jurisdictions applying it. Their legal effect depends on adoption and project requirements.

These references address related verification topics; the table does not assert formal equivalence or interchangeable certification. GB/T standards are recommended Chinese national standards, while GB 44240-2024 is mandatory. Its Clause 8.1 requires battery management to detect and control abnormal voltage, temperature and current conditions, linking BMS behavior to battery safety. [10–12]

For stationary storage, IEC 62619 and IEC 63056 address cells and batteries, while IEC 62933-5-2 addresses the safety of the grid integrated electrochemical storage system across its life cycle. BMS bench evidence contributes to that assessment, together with battery, converter and system tests. UL 1973 and UL 9540 likewise evaluate different product levels. Cell emulation does not replace the physical fire testing associated with UL 9540A or the installation assessment under NFPA 855. [4–9]

Automotive projects need their own approval and safety framework

For road vehicles, the ISO 26262:2018 series provides a functional safety framework for safety related electrical and electronic systems. BMS diagnostic and protection tests can contribute evidence for the assigned safety requirements; the applicable Automotive Safety Integrity Level (ASIL) follows the project hazard analysis and risk assessment. A simulator does not confer an ASIL rating. [13]

UN Regulation No. 100 addresses electric powertrain safety and rechargeable electrical energy storage system (REESS) approval for relevant vehicle categories. Apply the amendment series and transitional provisions required by the approval jurisdiction. Its vehicle and battery safety assessment is distinct from stationary storage BMS testing. [14]

European battery rules add BMS data obligations

Regulation (EU) 2023/1542 adds legal requirements for batteries placed on the EU market. Article 12 addresses stationary battery energy storage safety and supporting test evidence. Article 14 requires up to date data for the Annex VII parameters used to determine state of health and expected lifetime in the BMS of stationary storage, electric vehicle and light means of transport batteries. It also requires read only access under the conditions specified in that Article. [15]

The verification plan should therefore cover data storage, update behavior and access, alongside sensing and protection. Cell emulation supports controlled electrical inputs; lifetime and state of health assessment also need battery reference data and appropriate aging evidence.

Make the verification result repeatable and traceable

A useful BMS test record connects the requirement, applied input, measured response and acceptance criterion. Cell emulation makes channel errors and protection thresholds easier to reproduce. Integrated temperature, insulation, current and communication resources extend that evidence to the control sequence. Combined with real battery and system tests, this approach helps ITECH customers evaluate BMS behavior under controlled conditions and retain results that can be reviewed across design revisions.

References

[1] GB/T 34131-2023 Source [2] CSA/ANSI C22.2 No. 340-2023 Source

[3] IEC 62620:2014+AMD1:2023 Source [4] IEC 62619:2022 Source

[5] IEC 63056:2020 Source [6] UL 1973 and UL 9540 Source

[7] IEC 62933-5-2:2025 Source [8] NFPA 855 Source

[9] UL 9540A fire testing Source [10] GB/T 36276-2023 Source

[11] GB 44240-2024 Source [12] GB/T 42288-2022 Source

[13] ISO 26262:2018 scope Source [14] UN Regulation No. 100 Source

[15] Regulation (EU) 2023/1542 Source [16] ITECH IT6000C Source

[17] ITECH IT-M3100 Source [18] ITECH IT-M3900C Source

[19] ITECH IT-N6300 Source

Standards references checked on 14 October 2026. Use the editions and amendments specified for the project and approval market.