Applications / BMS Testing
BMS testing with controlled cell and sensor signals
Battery cells store energy. The battery management system (BMS) monitors their condition, detects unsafe states and triggers protective responses. This is essential in robots and drones, electric vehicles and stationary energy storage.
Test these responses with the comemso Battery Cell Simulator (BCS). Controlled cell and sensor signals replace real cells, so you can apply defined normal, boundary and supported fault conditions repeatedly.
Your path to BMS testing
Choose the setup for your BMS test
Start with the application, review a relevant project configuration and agree the technical requirements for your own setup.
Cells and controller
The cells store energy. The BMS monitors and protects them.
- Monitor cell conditionsThe BMS monitors voltage at each series position, alongside temperature and other safety-relevant signals.
- Protect the battery systemThe BMS detects unsafe conditions and triggers protective action against overcharge, deep discharge and overheating.
- Simulate cells and sensorsThe test system emulates cell voltages and sensor signals, allowing you to test BMS responses without real battery cells.
- Automate repeatable testsApply supported operating states and fault combinations with defined, repeatable inputs to validate BMS behaviour.
Conceptual battery-system illustrations. Cell and sensor signals are simulated when testing the BMS with a Battery Cell Simulator.
Application-specific priorities
Match BMS tests to the battery application
Start with the shared BMS functions, then add the operating profiles, interfaces and safe-state behaviour needed in the final application.
EV BMS testing for vehicle manufacturers and suppliers
Combine cell and sensor behaviour with high-voltage control, fast charging, regenerative braking, thermal management, isolation, contactors and vehicle communication.
- Dynamic current and temperature profiles
- CMC or CSC chain faults and sensor plausibility
- Coordination with VCU, OBC and EVCC
BMS IC and AFE testing for chip manufacturers
Characterize analog front ends and monitoring ICs before integrating a complete battery pack. Check conversion, diagnostics and communication, because errors in these functions affect downstream designs.
- Linearity, channel matching, noise and timing
- Open-wire and communication-chain diagnostics
- Regression across devices, lots and temperature
BESS BMS testing for energy storage manufacturers
Address long service life, rack and cluster structures, standby behaviour, parallel strings, module replacement and flat-voltage chemistries.
- Drift, imbalance and self-discharge
- Rack communication, isolation and contactors
- Ageing distributions, service states and recovery
BMS testing for AMRs, service robots and humanoid robots
Test the BMS against high actuator peaks, regenerative load changes and frequent docking. Account for compact batteries, limited cooling space and the safe states required during critical motion.
- Voltage sag and power-limit decisions
- Thermal and communication faults in motion
- Controlled derating, stop and dock behaviour
BMS testing for octocopters, drones and UAVs
Check how the BMS distinguishes a transient voltage sag from an unsafe battery state. Verify the remaining-power information under high discharge and rapidly changing loads.
- Cold, aged or imbalanced cells
- Emergency return or landing signals
- Vibration, temperature and wiring faults
BMS testing for research institutes and laboratories
Use configurable models, open interfaces and repeatable electrical conditions for new cell chemistries, estimation algorithms, balancing concepts and safety strategies.
- Parameter sweeps and algorithm comparison
- Open-loop and closed-loop HiL
- Traceable datasets and rapid reconfiguration
Anonymized project evidence
BMS validation and production testing in customer projects
Long-duration BMS validation
Over 2 months and thousands of test hours
A Tier 1 BMS development HIL setup integrated 240 simulated cells and 16 temperature channels to enable continuous start-stop cycles, rest periods, and fault-injection scenarios.
Environmental Robustness of an 800V BMS
240 simulated cells · 28 temperature channels
An OEM test architecture combined 240 simulated cells and 28 temperature channels with a climate chamber, enabling environmental stress testing of the BMS without exposing real cells to the same conditions or risks.
End-of-line testing for series-produced CMCs
5 production lines · 216 cells per production line
Five Battery Cell Simulator systems were integrated into five automated end-of-line stations for functional validation and automated fault diagnosis in series production.
Battery Cell Simulator integration with MATLAB models for research and algorithm development
Direct model integration for scalable cell simulation
A university research team integrated its own battery models directly into a 36-cell simulation system, scalable to 48 cells for repeatable algorithm development and validation.
Compact BMS development with integrated cell simulation
24 simulated cells · 8 temperature channels
A supplier replaced a power-supply-based test setup with an integrated Battery Cell Simulator. The system combined 24 simulated cell channels and 8 temperature channels for automated cell, sensor and fault simulation.
Test scenario: the battery reports a high temperature
Illustrative test: simulate a temperature signal above the controller’s specified threshold. Observe whether the BMS reports the condition and requests the required charging limit or stop. Restore the normal input and check the specified recovery behaviour. The thresholds and response times come from the controller requirements.
How to test a BMS
- Define the controller requirement and expected response.
- Select cell, sensor and supported fault inputs with the necessary range and load conditions.
- Match the Battery Cell Simulator modules, DUT supply, fixture/interlocks and automation interface.
- Apply the defined stimulus and capture the actual controller output.
- Compare observation against the pre-agreed threshold, timing and recovery conditions.
- Save the configuration, versions, run identity, data and interpretation.
For BMS HIL (hardware-in-the-loop) integration, distinguish the electrical simulator from the wider HIL environment. Confirm supported control interfaces and external components. Testing these controller reactions does not establish cell chemistry or whole-pack performance.
Plan the test around the application
Define the BMS test scope for your application
Verify the BMS decisions that keep vehicle charging and drive power, long-term storage operation, robot motion and unmanned-aircraft landing within their required limits.
Define the operating profile, energy level, voltage architecture, redundancy, environment, communication partners and acceptable fault response. Then specify test depth, model fidelity, signal channels and the evidence needed.
Design the BMS test system around the application requirements
Manufacturer and BMS test pioneer
Since 2011, comemso has developed Battery Cell Simulator hardware, control software and project-specific integration as one system for electrically controlled, repeatable BMS testing under normal, boundary and fault conditions.
In this configured HiL enclosure, the door interlock disables the BCS outputs.
Safety engineered into the test setup
The side enclosure holds the BMS and cell-monitoring units on a threaded grid plate. Its door interlock is coupled to the complete BMS HiL (hardware-in-the-loop); integrated DUT drawers use the same interlock principle. The sequence below shows how access disables the system and de-energises the BCS outputs.
- 1Mount the DUT
Fix the BMS and CMUs to the threaded grid plate and route the project-specific interfaces inside the enclosure.
- 2Close and enable
The door interlock becomes part of the BMS HiL enable chain before electrical testing starts.
- 3Open door detected
Opening the side enclosure or an integrated DUT drawer interrupts that interlock chain.
- 4System shuts down
The complete system is switched off and the BCS outputs become de-energised before access to the DUT.
BMS testing for mobile robots
Check robot operation as battery conditions change
A warehouse robot accelerates with a load, stops, recovers energy and starts again. Its battery must support changing power demand within safe limits. The BMS reports those limits; the robot controller must turn them into an appropriate operating response.
Repeat the limiting battery condition
Use cell simulation to apply a weak cell, imbalance or voltage drop, along with supported temperature-sensor signals and faults. Repeat the duty-cycle inputs and compare the BMS response before and after a software change.
Follow the response across controllers
Check the reported current or power limit, fault state and recovery conditions. With an integrated hardware-in-the-loop (HiL) setup, also observe how the vehicle or robot controller responds.
Cell and sensor simulation verifies electrical inputs and controller behaviour. Physical cooling performance, mechanical motion and stopping distance require their own tests.
| Test condition | What to observe | Useful evidence |
|---|---|---|
| One cell reaches its lower voltage limit during a peak load | Detection, permitted current and defined delay | Applied cell signal, BMS limit and time-aligned controller response |
| A temperature signal rises or becomes implausible | Configured warning, derating or fault reaction | Stimulus, diagnostic state and recovery threshold |
| The robot returns to charging after a hot duty cycle | Charging permission and recovery sequence | Battery state, charging request and release decision |
| A repeated cycle exposes an intermittent fault | Whether the reaction remains consistent across runs | Saved test configuration and comparable result records |
Set thresholds and expected timing from the BMS and system requirements. Available fault channels, communication capture and automation depend on the selected configuration.
BMS test methods: stimulation, automation, HiL and faults
Test methods
Choose direct stimulation, automation, models and faults for the BMS response you need to evaluate.
Open-loop stimulation
Apply deterministic cell and sensor values to test measurement accuracy, thresholds, I/O and basic protection logic.
Automated scenarios
Run repeatable sequences for boundary sweeps, regression, software releases and configuration variants.
Closed-loop HiL
Let a battery model react to BMS commands, load profiles and thermal conditions for dynamic algorithm validation.
Fault insertion
Apply controlled electrical, sensor and communication faults. Measure detection, reaction timing and recovery.
Environmental and endurance
Combine signal simulation with climate chambers, power cycling and long-duration operation.
Production and EOL
Use development test records to select fast, traceable checks for manufacturing and final inspection.
Controller and cell test scope
Battery-cell testing and BMS testing answer different questions.
comemso tests the BMS controller with controlled cell emulation. This makes normal, boundary and fault situations repeatable without real cells. Electrochemical capacity, power, ageing and thermal behaviour belong to battery-cell laboratory testing; cell chemistry is not characterised by the Battery Cell Simulator.
Continuous validation
BMS test records across the product lifecycle
Reuse development scenarios that help diagnosis in production and service.
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01
Concept and algorithms
Define hazards, operating states, model assumptions and requirements. Use model-in-the-loop or software-in-the-loop where appropriate.
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02
Electronics development
Characterize AFE (analogue measurement front end), CMC (cell management controller) and sensor interfaces with direct electrical stimulation and automated boundary sweeps.
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03
BMS integration
Validate the central controller, diagnostics, contactors, isolation, communication and model-based behaviour in HiL.
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04
Application validation
Connect the BMS to vehicle, BESS, robot or UAV subsystems and combine the test with environmental and endurance conditions.
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05
Production and service
Select the most useful cases for EOL, firmware regression, variant control and troubleshooting.
Specify the test system
Specify cell channels, sensor signals, faults and integration
Specify the electrical and functional behaviour required at the BMS connector from the application and acceptance criteria. Include the signal ranges, interfaces and integration needs alongside the channel count.
Cell count, chemistry, voltage range, module structure and expected dynamics.
Passive or active method, source and sink direction, current and measurement needs.
Temperature, current, pack voltage, isolation, digital I/O and communication.
Electrical faults, sensor failures, DUT handling and safe shutdown paths.
Static sequences, real-time models, test software, APIs and reporting.
Development, climate chamber, regression, EOL and future expansion.
Customer references
BMS-controller validation in practice
“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.”
Record BMS responses and test-system status together
Check connection and simulator-channel diagnostics alongside the BMS response. A setup fault can invalidate the intended cell condition and must be distinguished from DUT behaviour. The Battery Cell Simulator product page describes its supported module diagnostics and configuration-dependent interfaces.
Review Battery Cell Simulator connection and channel diagnostics
Deliberately injected DUT fault
Apply a supported fault, such as an open circuit, and compare the recorded BMS reaction with the response required for that condition.
Unintended test-system fault
Check connection and channel diagnostic flags before accepting a run. Define how the automation handles a test-system fault and an invalid result.
A clear diagnostic status is one prerequisite for credible evidence; it does not prove every aspect of a test valid. Automatic stop, quarantine and retest behaviour must be defined in the integration.
Evaluate the BMS response against the cell condition actually applied at the DUT. Record both together with the test-system status. Define the relevant accuracy, operating conditions and stability limits before deciding whether an observed deviation belongs to the BMS or the setup.
Test a cell condition together with sleep and wake behaviour
For a BESS standby test, define the intended sleep state, current-measurement range and allowed BMS response. Then introduce a supported undervoltage condition and examine the specified wake/sleep behaviour.
Controlled cell and sensor signals avoid waiting for real cells to charge or discharge between these defined states. Repeatable inputs and automation support regression after software or hardware changes. Include an appropriate electrical safety concept in the setup.
Illustrative test method, not a disclosed test from the BESS startup account. SOC, balancing and SOH-estimation tests require suitable algorithms, models and defined measurement scope; selecting a simulator does not validate them automatically.
Frequently asked questions
BMS testing FAQ
What is BMS testing?
BMS testing verifies the hardware and software functions that monitor, estimate, balance and protect a battery system. Apply normal operating conditions, limits, electrical faults and communication failures, then check the response and recovery.
How can a BMS be tested without a real battery?
A programmable cell and sensor simulator supplies the electrical inputs expected by the BMS. Engineers set cell voltages, temperatures, current signals and supported faults directly, without waiting for a physical pack to reach each state.
Which BMS functions should be validated?
Typical scope includes measurement, state estimation, balancing, contactor and pre-charge control, isolation monitoring, diagnostics, communication, wake and sleep behaviour, protection thresholds and recovery.
What is the difference between BMS testing and battery testing?
BMS testing validates the controller, algorithms, interfaces and protection decisions. Battery-cell testing characterises electrochemical cells or packs, including capacity, power, ageing and thermal behaviour. comemso focuses on the BMS controller and uses emulated cell signals; it does not characterise battery chemistry.
When is BMS HiL testing useful?
Use HiL when BMS algorithms and application interfaces need to react dynamically to a battery model. Closed-loop tests examine state estimation, balancing, power limits, contactors, charging and coordinated fault responses.
How does EV BMS testing differ from BESS BMS testing?
EV testing emphasizes dynamic drive, regenerative braking, fast charging and rapid power transitions. BESS testing emphasizes long-duration operation, standby, rack and cluster coordination, ageing distributions and service recovery.
How do BMS manufacturers ensure the quality and safety of their products?
BMS manufacturers verify defined controller requirements with battery management system testing. They keep each requirement, test case, observed response and release decision linked in the test record.
Engineers apply controlled cell deviations, balancing conditions and supported sensor faults, then check the required protection response, diagnostics, communication and recovery. They repeat relevant tests after hardware or software changes.
The configured comemso Battery Cell Simulator as a BMS tester supplies the selected cell and sensor signals and supported fault options. These tests verify specified BMS controller functions; they do not by themselves establish whole-battery safety or certify the finished product.
Review the detailed quality and safety checks. Follow the BMS test procedure. Select the Battery Cell Simulator configuration.
How do manufacturers verify BMS quality and safety?
Define the controller requirements and expected responses. Test measurement accuracy, protection thresholds, balancing, diagnostics, communication and recovery under controlled conditions.
The comemso Battery Cell Simulator as a BMS tester supplies configured cell voltages, sensor signals and supported electrical faults for these checks. Select the cell count, signal ranges, interfaces and fault options for the controller requirements.
A repeatable BMS test records the applied cell and sensor inputs, the observed controller response, relevant test-system diagnostics and the hardware/software configuration. Fault and regression tests repeat these checks after changes. BMS testing verifies the defined controller functions; it does not by itself establish whole-battery safety or certify the finished product.
Link each requirement to the test case, measured result and release decision. For a protection limit, record the requirement identifier, applied signal, expected response and timing, observed response and reviewer decision. Reuse the case in regression after a controller or test-system change.
How can BMS sleep behaviour and undervoltage response be tested together?
Define the permitted standby current, intended sleep state and required response to a cell undervoltage condition. Apply controlled cell and sensor signals, introduce a supported undervoltage condition and record current consumption, diagnostics and wake/sleep behaviour.
Compare the result with the controller requirement and repeat the test after software or hardware changes. That application requirement defines whether the BMS should remain awake or return to sleep.
BMS-controller test planning
Plan BMS validation
Start with the battery architecture, operating scenarios and required monitoring, balancing and protective responses. Specify the cell and sensor stimuli, fault cases and test records the setup needs to provide.