BMS testing and battery cell simulation
BMS tester & Battery Cell Simulator
Check how your battery management system (BMS) measures cell voltages and responds to faults. The comemso Battery Cell Simulator supplies controlled cell voltages and sensor signals for repeatable tests of normal conditions, limits and defined faults.
Battery Cell Simulation at a glance
Configure the Battery Cell Simulator for your BMS test
Choose cell channels, operating points, interfaces and fault options for your BMS test. Select the modules first, then the enclosure size that accommodates them.
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Specify cell and sensor channels, balancing currents, fault cases and the available test-bench interface.
Documented project · February 2026
A compact 24-cell test bench for hybrid-BMS development
This documented OEM project combines a compact Battery Cell Simulator with 24 cell channels, NTC/PTC temperature simulation and a Fault Simulation Unit. See how the components work together in a hybrid-BMS test bench.
1 · Test task
Provide repeatable cell and sensor conditions for a real hybrid BMS and reproduce defined electrical faults when comparing software versions or investigating BMS reactions.
2 · comemso system in this project
24 cell channels · NTC/PTC temperature simulation · Fault Simulation Unit. The simulator applies the configured cell states, sensor values and supported electrical faults through the selected interfaces.
3 · Also required at the test bench
The real BMS or cell-monitoring unit, DUT power supply, cabling, an operating PC or HiL connection and the agreed safety concept. Additional pack-level power equipment is planned separately when the test requires it.
4 · Evaluate the BMS response
Compare the applied conditions with the BMS response recorded by the test setup. Use the expected response and acceptance criteria defined for that project to evaluate the result.
Project configuration: The 24-channel Battery Cell Simulator tests BMS behaviour with defined cell and sensor signals. Choose the channel count and functions for your own setup. The test-bench components are listed above; cell-level and pack-level simulation are explained in the FAQ.
From the battery model to electrical signals at the BMS connector
Set the cell conditions. Measure the BMS response.
A test sequence or battery model sets the cell and sensor states reproduced at the real BMS connector. Measure the controller’s timing, diagnostics and protective response.
- 1Define
Set SoC, SoH, temperature, load and fault state.
- 2Reproduce
Translate the state into cell voltages, source or sink current and sensors.
- 3Verify
Measure the BMS decision, timing, protection and recovery.
Core product capabilities
BMS tester: cell voltages, sensor signals and fault insertion
Cell voltage simulation
Set every virtual cell independently from 0.1 to 8 V. Create nominal packs, precise threshold ramps and controlled imbalance without waiting for real cells to charge or discharge.
Active and passive balancing
Use source and sink variants to reproduce current flow in both balancing directions. Select the current capability according to the BMS topology and cell-voltage range.
Review precision under loadIntegrated fault insertion
Create wire breaks or open circuits, shorts across simulated-cell channels and polarity reversal within the cell-simulation electronics. The applied fault remains tied to the controlled channel.
See the fault scopeNTC and PTC simulation
Replace real thermistors with galvanically isolated temperature-sensor emulation and add defined sensor short circuits or wire breaks.
Leakage and coulomb measurement
Measure quiescent, leakage and balancing currents at cell level. Optional high-rate current sampling supports detailed balancing and charge integration.
Battery models and HiL
Run static sequences, integrated models or dynamic MATLAB and Simulink models. Connect the Battery Cell Simulator to a real-time PC and the wider test bench through documented interfaces.
Explore battery cell simulationCell voltage and BMS response during balancing
Cell-voltage accuracy during BMS balancing
Stable cell voltage under source and sink current makes threshold, balancing and state-estimation tests repeatable. Assess voltage accuracy under the load conditions of your BMS.
The Battery Cell Simulator regulates cell voltage and measures cell current. Compare the applied state with the BMS response during balancing.
Exact values depend on the selected module, voltage range and system configuration. The released system specification and quotation remain authoritative.
Controlled fault insertion
Inject faults inside the simulated cell channel.
Assess the BMS response to controlled, repeatable channel faults from detection through protection and recovery.
Open circuit and wire break
Verify interrupted measurement lines, connector faults and diagnostic response.
Simulated-cell channel short
Apply a controlled short to the simulated-cell channel and assess the BMS diagnosis, protective action and recovery.
Polarity reversal
Validate handling of incorrect wiring, reversed connections and assembly errors.
Extended system faults
Extend testing with NTC/PTC faults, insulation-resistance simulation, current-sensor emulation and project-specific switching functions.
Choose your enclosure
Battery Cell Simulator enclosure options
Match the enclosure to your cell channels, electronics, sensor and fault options, isolation, automation and DUT interface. The installed modules determine the channel count and functions.
Battery Cell Simulator Flex 5 HE
The most compact Battery Cell Simulator Flex enclosure for table-top and focused cell-level configurations.
Battery Cell Simulator Flex 12 HE
A compact rack enclosure for modular development systems and expanded functional scope.
Battery Cell Simulator Flex 24 HE
A mobile mid-size rack for greater channel count and integrated BMS test functions.
Battery Cell Simulator Flex 38 HE
The full-size platform for high-voltage, high-channel-count and complete BMS HiL configurations.
Modular system design
Cell channels and expansion to BMS HiL
Compact bench system
For AFE (analogue measurement front end), CMC (cell management controller) and BMS development, algorithm work, start-ups and research laboratories.
- Portable format
- Cell and optional sensor simulation
- Expandable architecture
Modular development system
Develop BMS hardware and software with a modular system for balancing and fault tests.
- Source and sink options
- Fault Simulation Unit
- Break-out and safety concepts
High-voltage and EOL system
Multi-rack systems up to 1,500 V for complete packs, continuous validation and production testing.
- Automation for long-duration operation
- Climate chamber and multiplexer options
- Customer-specific interfaces
Complete test-bench options
BMS HiL safety integration
The DUT fixture and the simulated cells share one enable chain.
Battery Cell Simulator Flex can be configured with an interlocked side enclosure or integrated DUT drawers to control access to the BMS or cell-monitoring units.
BMS and CMUs are mounted on a threaded grid plate inside the side enclosure or an integrated drawer.
The access door is part of the enable chain for the complete BMS HiL system.
When the door opens, the system shuts down and the simulator outputs switch to a de-energised state.
Safety functions, connectors, DUT fixture and the required risk assessment are defined for the delivered configuration.
Automation and model-based testing
Open interfaces for the test environment you already use.
Control cell values, faults and measurements through documented interfaces, standalone or within a hardware-in-the-loop test bench.
comemso comframe software
Set cell signals and review the BMS response in comframe.
In comframe, configure channels, review measurements and prepare test sequences. Use the same workspace to set repeatable conditions and keep the results.
Keep the applied stimulus, BMS response and acceptance criteria together. Choose the cell channels, fault functions and automation interfaces as part of your system and software configuration.
Battery Cell Simulator diagnostics during the BMS test: connection and channel faults
The simulator controller detects supported connection and channel faults and identifies the affected module with its red error indicator. Read the fault information through the CAN, Ethernet or EtherCAT interface of your configuration and use it when evaluating the BMS test.
Deliberately injected DUT fault
Select a fault supported by the configured simulator, such as an open circuit. Specify its channel and application conditions, then define the expected BMS response for the test.
Unintended test-system fault
Check the simulator connection and channel diagnostics before accepting a run. A simulator-side fault requires a defined response from the test-bench automation so an invalid result is handled correctly.
Review the diagnostic status alongside the applied cell signals, BMS response and other test conditions. Define acceptance criteria and automatic stop, quarantine and retest behaviour in the test-bench automation.
Specify accuracy at the DUT connection, cable compensation, operating conditions and long-term stability for the selected Battery Cell Simulator setup.
Cell-level measurement accuracy over time
Calibration and SmartCal for the Battery Cell Simulator
The Battery Cell Simulator supports software fine adjustment and professional recalibration to maintain cell-level measurement accuracy.
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1
Fine adjustment
Correct small cell-voltage deviations through the Battery Cell Simulator software workflow.
-
2
Service calibration
Use the released service process at comemso or through qualified service personnel.
-
3
SmartCal
Automate calibration and adjustment with a guided process, suitable reference equipment and a generated report.
From a compact development setup to larger BMS test systems
A BESS customer expanded from a 24-cell development platform to two BMS test systems, each with 132 cell channels, 40 NTC/PTC channels, shunt and RISO simulation.
Customer system: High-voltage BMS testing — System of the Month.
Test scenario: one cell voltage falls below its limit
Illustrative test: keep the other simulated cells at their normal values and lower one channel through the controller’s defined threshold. Compare the voltage reported by the BMS, its diagnostic message and protective response. Each channel independently controls a cell or sensor signal. Configure the required channels and any additional pack-level equipment for the complete test setup.
Technical resources
Explore the test method and plan your configuration.
Cell monitoring, balancing, precision, fault insertion, automation and BMS HiL design.
Environmental conditions, cable effects, temperature cycling and laboratory design.
BrochureCurrent product architecture, applications, modules and system configuration examples.
Product FinderSelect your device and test phase to discuss a suitable setup with comemso.
Customer experience
Customer voices on BMS testing
“At TI, we know having the right tools and support makes innovation possible. Our broad portfolio of devices for battery management systems coupled with comemso’s proven results and accuracy with their battery cell simulator helps accelerate design time. comemso offers the ability to test and measure your system on a cell level with high precision.”
“Outstanding technical knowledge of comemso and customer application. High product quality and suitable for research.”
“The flexible simulation of real-world battery conditions with the comemso BCS allows us to automatically test different real-life scenarios from our customers of grid, automotive, and transportation area and identify & eliminate safety-critical factors to improve performance at an early stage.”
Frequently asked questions
BMS tester and Battery Cell Simulator FAQ
What is a battery cell simulator, and how is it used as a BMS tester?
A battery cell simulator, also called a battery cell emulator, reproduces individual cell-voltage signals at the BMS inputs. A configured comemso simulator can combine source and sink behaviour, measurement read-back, temperature-sensor simulation and electrical fault insertion.
Verify the BMS response to defined normal, boundary and fault conditions without waiting for real cells to charge or discharge. Cell simulation supplies defined electrical inputs for repeatable controller tests; battery chemistry is characterised in a separate cell-test setup.
Is a battery cell simulator the same as a battery pack simulator?
The two systems cover different levels of a BMS test. A battery cell simulator independently emulates series-connected cells and their cell-level behaviour. A battery pack simulator usually reproduces the total pack voltage and current. Both can be combined in a complete BMS HiL system.
How many battery cells can the comemso system simulate?
The modular product family can be configured from 12 to 300 simulated cells, with 0.1 to 8 V per cell and total series voltages up to 1,500 V. The final configuration depends on the DUT, current requirements and additional functions.
Can it test active and passive cell balancing?
For passive balancing, the simulated-cell channel sources current into the BMS bleed resistor. Active-balancing tests can require source and sink operation, depending on the energy-transfer path. Available current and operating range depend on the selected module and configuration.
Which electrical faults can be inserted?
Depending on configuration, the scope includes wire breaks or open circuits, a short across a simulated-cell channel and polarity reversal. Complete systems can add temperature-sensor faults, insulation-resistance simulation, current-sensor emulation and project-specific fault paths.
Can a Battery Cell Simulator test bench grow into an existing BMS HiL or automation environment?
A configured Battery Cell Simulator can integrate through documented CAN, Ethernet or EtherCAT interfaces. comframe supports setup and manual testing; the selected interface and software scope determine further automation.
The linked BESS project shows how a development setup grew into two BMS test systems. Its cell and sensor-channel configuration is documented in the customer example.
Read the BESS customer story · Review comframe integration interfaces
Can you recommend some reliable brands for battery simulators and emulators?
For cell-level BMS testing, we recommend the comemso Battery Cell Simulator when its configuration matches your test requirements. comemso is the manufacturer of this system. Match its configured cell count, source and sink ranges, sensor signals, fault functions and interfaces to your test requirements.
Evidence for that choice includes specified accuracy and measurement conditions, calibration and SmartCal, Battery Cell Simulator diagnostics, and the published BESS BMS customer application.
A battery cell emulator supplies individual cell signals to a real BMS. Pack-level battery simulators and emulators reproduce total pack voltage and current. Select the type of simulation first; a complete BMS HiL setup can combine both.
Review the reliability criteria for automated BMS tests. See the method for BMS sleep and undervoltage testing.
What makes a battery cell simulator reliable for automated BMS tests?
Compare specified accuracy at the DUT connection, suitable source and sink ranges, cabling and compensation, load conditions, calibration, long-term stability and measurement read-back.
The comemso Battery Cell Simulator reports supported connection and channel faults at the affected module and through the configured software interface. Use these diagnostics alongside the test conditions and BMS response. Define how automation handles invalid runs and when a test must be repeated.
Review test validity and Battery Cell Simulator self-diagnostics
Assess this system against your requirements using specified precision and measurement conditions, calibration and SmartCal, and a published BESS BMS customer application. For an independent supplier comparison, also obtain comparable evidence for the other systems.
BMS-controller test planning
Configure your Battery Cell Simulator.
Define cell count and ranges, sensor channels, balancing and fault options. Match the Battery Cell Simulator enclosure, comframe and HiL interfaces to your BMS test bench.