Pack Testing

Pack testing is the final validation gate before a battery pack enters service. By this stage the cell chemistry has been characterised, the module or string has been verified in isolation, and the BMS software has been exercised in Hardware-in-the-Loop (HIL) simulation. Pack testing confirms that every subsystem (electrical, thermal, mechanical, and control) performs correctly as an integrated whole and that the pack is safe and compliant across its full operating envelope.

The tests fall into seven categories:

  • Control System: verification that the BMS operates the pack safely and predictably under all commanded and fault conditions
  • Performance: electrical energy and power delivery over the full range of temperature, state of charge, and age
  • Thermal: thermal control system effectiveness, cooling capacity, and temperature homogeneity across the pack
  • Electrical: high-voltage system integrity including isolation resistance, earthing, and insulation coordination
  • Mechanical: structural integrity, enclosure sealing, and dynamic durability under vibration, shock, and crash loading
  • Abuse Tests: pack behaviour at and beyond safe operating limits, required for safety system validation
  • Legislative / Certification Testing: standards compliance for transport, market access, and regulatory sign-off
Control System

The BMS will have been exercised at software model level and through HIL simulation before hardware is available. Pack-level control system testing verifies that the real hardware, firmware, and communication interfaces behave as specified under conditions that simulation cannot fully replicate, including contactor sequencing timing, real sensor noise, and actual thermal inertia.

See BMS Testing for the standalone BMS test programme this pack-level testing builds on.

Wake-up and Power-Down Sequencing

  • Contactor Close and Open Sequence
    • Procedure: Command wake-up from a defined sleep state; monitor pre-charge resistor current, main positive and negative contactor close timing, and HVIL integrity throughout
    • Outputs: Contactor timing vs. specification; pre-charge completion voltage; sequence repeatability across temperature range
    • Relevance: Incorrect sequencing causes inrush current damage or contactor welding; cold-start timing is often the hardest condition to pass
  • Isolation Monitoring at Start-up
    • Procedure: Verify isolation resistance measurement is performed before contactors close and that a detected fault prevents close
    • Standard: ISO 6469-4; FMVSS 305; ECE R100
    • Outputs: Isolation resistance threshold response; false-positive rate across temperature and humidity
  • Communication Broadcast Verification
    • Procedure: Verify that all CAN messages (or LIN / Ethernet as applicable) are broadcast at correct timing and contain valid signals on power-up
    • Outputs: Message timing vs. DBC specification; signal scaling and offset verification

Operational Control Limits

  • Charge and Discharge Power Limiting
    • Procedure: Command charge and discharge beyond BMS-broadcast power limits; verify the pack reduces current correctly via the contactor or current limit signal
    • Outputs: Correct enforcement of Pmax_charge and Pmax_discharge vs. SoC and temperature; response latency
    • Relevance: Power limits must be enforced in real hardware, not just modelled in HIL
  • Voltage and Current Limit Response
    • Procedure: Drive pack to minimum and maximum voltage limits at a range of C-rates and temperatures; confirm cell-level and pack-level cut-off occurs at the correct thresholds
    • Outputs: Cut-off voltage accuracy vs. temperature; current limit enforcement timing
  • Over-temperature Response
    • Procedure: Reduce or block coolant flow to drive cells toward temperature limits; confirm BMS de-rates power and ultimately opens contactors at defined thresholds
    • Outputs: De-rate onset temperature; contactor open threshold; temperature sensor spatial coverage adequacy

Thermal Management Control

  • Cooling Request Verification
    • Procedure: Apply thermal load by cycling pack at defined C-rates; verify BMS issues coolant pump and chiller/heater requests at correct temperatures
    • Outputs: Coolant pump request hysteresis; target coolant supply temperature; control latency
  • Heating Request and Cold-Soak Start
    • Procedure: Cold soak pack to minimum storage temperature; verify BMS issues heat request before or during charge enable, and that charge current is correctly de-rated below defined temperature
    • Outputs: Heating enable threshold; charge current ramp vs. temperature; time to reach minimum charge temperature
  • Temperature Sensor Plausibility Checks
    • Procedure: Disconnect individual temperature sensors; verify BMS detects open-circuit or out-of-range sensor and responds with appropriate fault and fallback strategy
    • Outputs: Fault detection latency; graceful degradation behaviour; absence of latent dangerous conditions on sensor loss

Charger Handshake

  • AC Charger (OBC) Communication
    • Procedure: Connect pack to on-board charger; verify CAN/PLC handshake, charging mode negotiation (CC-CV), and charge termination sequence
    • Standard: IEC 61851-1; ISO 15118-2 (V2G); CHAdeMO / CCS as applicable
    • Outputs: Charge initiation timing; current request accuracy; charge termination and contactor open sequence
  • DC Fast Charge Protocol
    • Procedure: Connect pack to DC fast charge supply; verify Combined Charging System (CCS) or CHAdeMO protocol execution, current ramp and taper, and thermal management activation
    • Outputs: Maximum accepted charge power; power roll-off vs. SoC and temperature; charge session interoperability

SOX Estimation Accuracy

  • State of Charge (SoC) Accuracy
    • Procedure: Run pack through defined discharge profiles with periodic rest periods; compare BMS-reported SoC against reference coulomb-counting measurement
    • Outputs: SoC estimation error (%) vs. SoC, temperature, and age; worst-case error at low SoC approaching cut-off
  • State of Health (SOH) Accessibility
    • Procedure: Verify BMS broadcasts or makes accessible an SOH value via diagnostic protocol (e.g. UDS / ISO 14229)
    • Standard: EU Battery Regulation 2023/1542 (Battery Passport requirement)
    • Outputs: SOH value correctness vs. measured capacity; update frequency

Cell Balancing

  • Passive Balancing Verification
    • Procedure: Pre-condition pack with deliberate cell SoC spread; run to full charge and verify balancing dissipates the spread within the expected time
    • Outputs: Balancing current accuracy; convergence time; thermal impact of balancing on pack temperature
  • Active Balancing Verification (where fitted)
    • Procedure: Verify charge transfer between cells occurs in the correct direction and at the expected rate; confirm no energy is wasted to heat under normal operating conditions
    • Outputs: Balancing efficiency; impact on charge time and capacity recovery
Performance

The pack must deliver its rated energy and power across the full application operating envelope. Performance data from pack testing feeds warranty definitions, range estimation, and customer-facing specifications.

Pack Capacity

  • Reference Capacity Test
    • Procedure: Condition pack at 25°C; CC-CV charge to maximum pack voltage; rest; CC discharge at C/5 to minimum pack voltage
    • Outputs: Usable capacity (Ah); usable energy (Wh); pack-level coulombic efficiency; comparison to sum-of-cells prediction
    • Note: Losses due to inter-cell imbalance and BMS overhead are only observable at pack level
  • Capacity vs. Temperature
    • Procedure: Repeat reference capacity test at soak temperatures covering the application range (e.g. −20°C, −10°C, 0°C, 10°C, 25°C, 40°C)
    • Outputs: Capacity derating curve vs. temperature; minimum temperature for acceptable range; input to thermal management set-point optimisation
  • Capacity vs. Discharge Power
    • Procedure: Discharge at C/5, C/2, 1C, 2C, and maximum continuous power rating
    • Outputs: Ragone curve at pack level; rate-dependent capacity loss attributable to resistive losses and BMS limit enforcement

Pack Power Map

  • Continuous and Peak Power vs. SoC and Temperature
    • Procedure: Execute HPPC-style pulse sequence at defined SoC steps and soak temperatures; record 10-second and 30-second peak power, and continuous sustainable power
    • Outputs: Power map (kW) vs. SoC and temperature; comparison against BMS-broadcast power limits to verify limit accuracy
  • Pulse Power at Low Temperature
    • Procedure: Cold soak to minimum operating temperature; apply peak power demand and monitor voltage response
    • Outputs: Minimum SoC and temperature at which rated peak power is delivered; ramp-up behaviour

Fast Charge Performance

  • Charge Time and Power vs. Temperature
    • Procedure: Fully discharge pack; cold soak or heat soak to defined starting temperature; initiate fast charge and record power accepted, SoC progression, and temperature rise throughout
    • Outputs: Time to 80% SoC (the standard EV fast-charge metric); peak accepted power; thermal rise during charging; comparison against specification
  • Charging Power Curve (Charge Map)
    • Procedure: Record charge current and voltage accepted at each 5% SoC step from 5% to 100% at multiple temperatures
    • Outputs: Full charge power map vs. SoC and temperature; input to charge time estimation and fast-charge station compatibility assessment
Thermal

Thermal performance at pack level is distinct from module-level thermal testing because it includes the complete cooling circuit, the thermal management control system, and the thermal interactions between modules sharing a common coolant loop.

Cooling System Performance

  • Cooling Flow Rate vs. Backpressure
    • Procedure: Measure coolant flow rate through the pack circuit at defined pump speeds; record inlet and outlet pressure differential
    • Outputs: Pack hydraulic resistance curve; minimum required pump head at maximum flow; confirmation against cooling circuit design model
  • Thermal Performance Under Load
    • Procedure: Cycle pack at maximum continuous power with coolant supplied at defined temperature and flow rate; record cell temperature distribution at steady state
    • Outputs: Maximum cell temperature rise above coolant inlet; temperature non-uniformity (delta T) across the pack; confirmation against thermal model prediction
  • Maximum Temperature Operating Limit
    • Procedure: Reduce coolant flow or increase ambient temperature until cell temperatures approach operating limit; verify BMS de-rating and thermal management response
    • Outputs: Cell temperature at which de-rating begins; maximum cell temperature observed; adequacy of thermal management response

Cold Start and Heating Performance

  • Cold Soak Conditioning
    • Procedure: Soak pack at minimum storage temperature for minimum 8 hours; attempt charge initiation; record cell temperatures and time to reach minimum charge-enable temperature with heater active
    • Outputs: Heating power draw; time to charge-ready condition; cell temperature distribution during warming
  • Heater Circuit Verification
    • Procedure: Verify coolant heater or PTC cell heater activates correctly on BMS command; measure power consumption and heating rate
    • Outputs: Heater power vs. supply voltage; temperature rise rate at minimum ambient

Thermal Runaway Propagation

  • Triggered Thermal Runaway Propagation Test
    • Procedure: Initiate thermal runaway in a single cell or module using external heating or nail penetration; monitor propagation to adjacent cells and pack-level response
    • Standard: GB/T 38031 (China); UN GTR 20; ECE R100 Amendment 3; ISO 6469-1
    • Outputs: Propagation time and pattern; gas venting volume and direction; pack-level event classification (no propagation / contained propagation / full propagation); effectiveness of cell-to-cell thermal barrier
    • Relevance: Regulatory requirement for EV traction packs in most major markets; results directly inform vent path design, cell spacing, and intumescent pad specification

UL 9540A frames pack-level propagation testing as one tier in a four-tier cell → module → unit → installation sequence, escalating from a single-cell trigger up to a full-installation fire test. The mechanisms and containment strategy behind the results above are covered in more depth on Pack Thermal Runaway and its Propagation Resistance Testing page; the module tier that feeds into this test is covered on Module Testing, and the installation tier above pack level is covered on BESS Testing.

Electrical

Pack-level electrical testing verifies the integrity of the high-voltage system as a complete assembly, including insulation, isolation, and earthing continuity that cannot be fully assessed at cell or module level.

Isolation Resistance

  • High-Voltage Isolation Test
    • Procedure: Apply high-voltage DC (typically 500 V or 1000 V DC) between HV positive, HV negative, and pack chassis/earth; measure leakage current; calculate isolation resistance
    • Standard: IEC 62196; ISO 6469-4; ECE R100; FMVSS 305
    • Outputs: Isolation resistance (MΩ); minimum acceptable: typically 100 Ω/V for EV traction packs
    • Relevance: Fundamental safety requirement; isolation failure creates electric shock hazard to first responders and service personnel
  • IMD Function Check
    • Procedure: Verify the on-board Isolation Monitoring Device responds correctly to introduced isolation faults of defined resistance; confirm fault is flagged to vehicle controller and driver warning is activated
    • Outputs: Detection threshold accuracy; response time; correct fault behaviour

Dielectric Strength

  • AC Hipot Test
    • Procedure: Apply AC voltage (e.g. 2 × Vmax + 1000 V AC for 1 minute) between HV circuit and pack enclosure
    • Standard: IEC 62196-1; ECE R100; ISO 21498-2
    • Outputs: Pass/fail on dielectric withstand; leakage current below limit; no breakdown or flashover
    • Relevance: Validates creepage and clearance design and insulation material selection

Earth Continuity

  • Protective Earth Resistance Check
    • Procedure: Measure resistance between HV system earth point and all accessible conductive parts of the pack enclosure
    • Standard: ISO 6469-4; IEC 62196
    • Outputs: Earth resistance (mΩ); maximum permissible typically 100 mΩ

External Short Circuit

  • Pack-Level Short Circuit Response
    • Procedure: Apply low-resistance external short (≤5 mΩ) across the pack HV terminals with main contactors closed
    • Outputs: Fuse response time and energy to clear; maximum current reached; absence of thermal event; contactor integrity post-test
    • Relevance: Validates fuse coordination with contactor and BMS short-circuit detection
Mechanical

Mechanical testing at pack level encompasses structural integrity of the enclosure, sealing against environmental ingress, and dynamic durability under the vibration, shock, and crash loading that reflects the full service life of the vehicle or application.

Enclosure Sealing

  • IP Rating Verification (Dust and Water Ingress)
    • Procedure: Tests performed to IEC 60529 standard for the IP code claimed (typically IP67 for automotive traction packs)
    • Standard: IEC 60529; ISO 20653 (road vehicles)
    • Tests include: IP6X dust ingress (talcum powder chamber); IPX7 immersion (1 m depth, 30 minutes); IPX9K high-pressure wash (80°C, 100 bar at close range)
    • Outputs: Pass/fail on internal inspection for ingress; absence of water in HV compartment post-test
  • Pressure Change / Altitude Simulation
    • Procedure: Subject sealed pack to rapid pressure reduction representing maximum operational altitude (e.g. 4000 m); return to ambient; inspect for ingress or seal failure
    • Standard: UN 38.3 T.1; IEC 62660-2
    • Outputs: No leakage; seals intact; vent valve function (if fitted) verified
  • Humidity and Condensation Exposure
    • Procedure: Temperature-humidity cycling to simulate stored and deployed condensation conditions; typically per IEC 60068-2-30 or equivalent OEM specification
    • Outputs: No corrosion of HV terminals or BMS connectors; no condensation inside HV compartment; isolation resistance within limit post-test

Vibration

  • Random Vibration (Vehicle Road Load)
    • Procedure: Mount pack on vibration table using production mounting points; apply PSD profile representing vehicle lifetime road load in X, Y, and Z axes for defined duration
    • Standard: SAE J2380; IEC 62660-2; ISO 12405-4
    • Outputs: Pass/fail on isolation resistance, capacity, and visual inspection post-test; no loosening of fasteners or busbars
  • Sine Sweep (Resonance Search)
    • Procedure: Swept sinusoidal excitation from 10 Hz to 150 Hz at low amplitude; identify resonant frequencies of pack structure
    • Outputs: Resonant frequencies; amplification factors; input to structural design review and endurance test duration calculation

Mechanical Shock

See Shock Test for the cell-level equivalent procedure.

  • Half-Sine Shock Pulse
    • Procedure: Apply defined peak deceleration pulse (e.g. 30 g, 11 ms half-sine) in each of six orientations (±X, ±Y, ±Z)
    • Standard: IEC 62660-2; ISO 12405-4
    • Outputs: Pass/fail on isolation resistance and capacity post-test; no mechanical damage to enclosure, mounts, or internal busbars

Crush and Impact

See Crush Testing for the cell-level equivalent procedure.

  • Crush Test (Side and Bottom)
    • Procedure: Quasi-static crush force applied to pack in defined directions using flat plate; force and displacement recorded
    • Standard: ECE R100; SAE J2464; GB/T 38031
    • Outputs: Force at onset of deformation; absence of fire or explosion; isolation resistance maintained
  • Projectile Impact (Pole Impact / Gravel Strike)
    • Procedure: Simulated gravel or pole impact on underside and sides of pack; validates underbody protection design
    • Outputs: No thermal event; no HV isolation fault; no coolant leakage

Drop Test

See Drop Test for the cell-level equivalent procedure.

  • Free Fall Drop
    • Procedure: Pack dropped from defined height (typically 1 m) onto hard surface in specified orientations
    • Standard: UN 38.3 T.4 (for transport); OEM specifications for production packs
    • Outputs: No fire, explosion, or hazardous leakage; isolation resistance maintained

Crash Testing

  • Frontal, Rear, and Side Impact
    • Procedure: Pack subjected to representative structural crash loads via barrier or sled test; designed to replicate pack deformation in a vehicle crash at defined severity
    • Standard: ECE R100; FMVSS 305; GB/T 31498; Euro NCAP (indirectly, via vehicle test)
    • Outputs: No fire or explosion during or after 1-hour observation; no electrolyte leakage creating ground hazard; isolation resistance maintained or BMS isolation fault correctly raised
Environmental

Dust and water ingress are covered under Enclosure Sealing, above. The remaining climatic tests check the pack’s tolerance to humidity and salt exposure over its service life.

  • Humidity / Damp Heat: steady-state or cyclic exposure per the IEC 60068-2 series, checking high-voltage connector and busbar corrosion and insulation resistance over extended storage or operation
  • Salt Spray / Corrosion: per IEC 60068-2-11 or ASTM B117, for packs mounted in coastal, marine, or de-icing-salt road environments
Abuse Testing

Abuse testing establishes the safety behaviour of the pack at and beyond the boundaries of normal operation. These tests are expensive to execute, require heavily instrumented packs, and must be conducted in facilities rated for HV electrical events and fire. The tests are directly linked to legislative sign-off and safety system design validation.

The Electrical, Thermal, and Mechanical Abuse tests below are the pack-level counterparts to Abuse Testing and the cell-level Abuse Tests covered under Cell Testing; see Safety Testing for the wider safety-case context these results feed into.

Electrical Abuse

  • Overcharge
    • Procedure: Charge pack beyond maximum pack voltage at defined current; continue until BMS terminates, fuse clears, or event occurs
    • Standard: UN 38.3 T.7; ECE R100; IEC 62133
    • Outputs: BMS response and cut-off timing; outcome classification (no event / venting / fire)
  • Over-discharge
    • Procedure: Discharge pack beyond minimum pack voltage; evaluate BMS response and cell reversal risk in weakest cell
    • Outputs: Cut-off response; absence of internal short circuit from copper dissolution; BMS isolation of weakest cells where applicable
  • External Short Circuit
    • Procedure: Apply low-resistance short across pack terminals; verify fuse coordination and absence of thermal event
    • Standard: UN 38.3 T.5; ECE R100
    • Outputs: Fuse interruption time; peak current; temperature rise; pass/fail on fire and explosion criteria
  • Fast-Charge Durability
    • Procedure: Applies to cells that fast-charge from 20% to 80% state of charge in 15 minutes or less (around 2.4C average over that window), excluding cells that can only be charged from an on-board energy source. Cell completes 300 partial fast-charge cycles with prescribed rest intervals, then undergoes an external short-circuit test
    • Standard: GB 38031-2025
    • Outputs: Capacity and resistance trend over the 300 cycles; pass/fail on the following short-circuit test (no fire, no explosion)

Thermal Abuse

  • Thermal Stability (Oven Test)
    • Procedure: Fully charged pack placed in environmental chamber raised to defined temperature (typically 130°C or application-defined limit)
    • Standard: UN 38.3 T.2; ECE R100
    • Outputs: No fire or explosion; maximum temperature reached; isolation integrity
  • Local Heating / Fire Exposure (Thermal Runaway Propagation)
    • Procedure: A target cell is driven into thermal runaway using one of three accepted trigger methods, external heating, nail penetration, or internal heating via a prepared cell with an embedded heating pad, and the pack must issue a thermal-event alarm within 5 minutes. Observation continues for a minimum of 2 hours and does not end until every monitored point has cooled to 60°C or below
    • Standard: ECE R100 Amendment 3; SAE J2929; ISO 6469-1; GB 38031-2025
    • Outputs: Time to alarm; peak temperatures at each monitored point; whether propagation to neighbouring cells occurred; no explosion; structural containment; occupant protection maintained
    • Note: GB 38031-2025 tightened this considerably from the previous version, which only required propagation to be delayed long enough to give a 5-minute warning before the passenger compartment was endangered. The current requirement is no fire or explosion at all, with the alarm and observation criteria above. Smoke released in the alarm window is also now assessed differently depending on test level, at pack/system level the manufacturer must document that it isn’t dangerous in the passenger compartment, at full vehicle level none may enter the compartment at all

Mechanical Abuse

Note: this is a pack-level test. A separate vehicle-level underbody test exists under GB 18384-2025, using a towed whole vehicle over a fixed barrier rather than an impactor on a bench-mounted pack, worth distinguishing the two if you cross-reference

  • Penetration
    • Procedure: Steel rod or nail driven through pack structure at defined rate; triggers internal short circuit in cells
    • Outputs: Absence of explosion; containment of thermal event; vent path effectiveness
    • Note: This is one of the three GB 38031-2025 trigger methods for the thermal runaway propagation test above, alongside external heating and internal heating
  • Bottom (Underbody) Impact
    • Procedure: A 10 kg impactor with a 30 mm hemispherical head of #45 steel strikes the underside of the pack at three manufacturer-defined risk points, front, middle, and rear. Each impact carries 150 J. N-category vehicles (vans and trucks) are exempt where the pack has at least 200 mm ground clearance at full load
    • Standard: GB 38031-2025
    • Outputs: Visible leakage; housing integrity; insulation resistance; fire/explosion, all assessed after a 2-hour observation period
Legislative and Certification Testing

Legislative requirements are set early in the design process when the application is defined. The applicable standards determine the minimum test matrix required for market access, and many tests overlap with those described in the abuse and mechanical sections above.

Transport Certification

  • UN/DOT 38.3 (UN Manual of Tests and Criteria, Part III, §38.3)
    • Scope: Mandatory globally for shipment of lithium batteries by air, sea, road, and rail; applies to packs as shipped (typically at ≤30% SoC for transport)
    • Test series: T.1 Altitude simulation; T.2 Thermal test; T.3 Vibration; T.4 Shock; T.5 External short; T.6 Crush / impact; T.7 Overcharge; T.8 Forced discharge

Road Vehicle Approval

  • ECE Regulation R100 (Amendment 3)
    • Scope: UN approval for rechargeable energy storage systems (REESS) in electric vehicles; recognised across Europe and many markets globally
    • Key tests: Vibration; thermal shock; mechanical shock; external short; overcharge; over-discharge; thermal stability; fire resistance; thermal runaway propagation with no explosion / no fire propagation to passenger compartment
  • FMVSS 305a (USA) (updated from FMVSS 305, and scope corrected)
    • Scope: Federal Motor Vehicle Safety Standard, mandatory for US light vehicles from 1 September 2027. Covers fire/explosion avoidance and electrolyte containment following crash, plus a driver thermal-event warning requirement
    • Key tests: No fire or explosion from impact through one hour after the specified crash-test sequence; no electrolyte leakage, rupture, venting, fire, or explosion in specified vehicle-control tests; driver thermal-event warning within 3 minutes of onset, sustained for at least 5 minutes
    • Note: the 3-minute warning window is shorter than GB 38031-2025’s 5-minute alarm requirement, and the two use different test sequences, so meeting one doesn’t automatically satisfy the other
  • GB 38031-2025 (China)
    • Scope: Mandatory national standard for power battery packs and systems for electric vehicles sold in China. New vehicle model approvals must comply from 1 July 2026; models already approved for sale have until 1 July 2027. The transition applies to model approvals only, not to recall or retrofit of vehicles already sold or registered
    • Key tests: Vibration; mechanical shock; simulated collision; external short; overcharge; overdischarge; thermal stability; bottom (underbody) impact; fast-charge durability (300 partial cycles then external short); thermal runaway propagation, triggered by external heating, nail penetration, or internal heating, with a thermal-event alarm required within 5 minutes and no fire or explosion through a 2-hour observation period
    • Note: this replaces the previous requirement, which only required propagation to be delayed long enough to give a 5-minute warning before the passenger compartment was endangered, rather than requiring no fire or explosion at all
  • GB 18384-2025 (China)
    • Scope: Mandatory companion vehicle-level standard, covering the whole EV rather than the pack. Requires a driver-accessible physical cut-off for propulsion power, a vehicle-level underbody impact test (towed vehicle over a fixed barrier, distinct from GB 38031-2025’s pack-level impactor test), and a driver warning directly linked to the GB 38031-2025 thermal-event alarm. Same transition timeline as GB 38031-2025
    • Key tests: Underbody impact (150 mm barrier, 35 km/h, towed vehicle); post-impact IPXXB protection, no electrolyte leakage within 30 minutes, no fire/explosion within 2 hours; driver warning (light and sound) triggered by the traction battery’s thermal-event signal
  • ISO 12405-4
    • Scope: Internationally recognised performance and cycle life standard for traction battery packs; less prescriptive than legislative standards but widely referenced in procurement specifications

EU Battery Regulation (2023/1542)

The EU Battery Regulation came into force in August 2023 and is being phased in from 2024. It introduces performance, durability, sustainability, and traceability requirements with direct implications for pack-level testing and data reporting for batteries placed on the EU market.

  • Performance and Durability Requirements
    • Scope: Minimum capacity retention thresholds and fade limits after defined cycle counts; rated capacity accuracy requirements; applies to EV traction batteries and industrial batteries above 2 kWh
  • Battery Passport
    • Scope: Unique identifier linked to a digital record containing electrochemical performance, material composition, carbon footprint, and supply chain data; SOH must be readable from BMS and accessible via QR code or RFID
  • Carbon Footprint Declaration
    • Scope: Required from 2025 for EV traction batteries; requires lifecycle carbon footprint data from cell manufacturing through to end-of-life recycling

Functional Safety (ISO 26262 / ISO 13849)

  • FMEA and Fault Injection Testing (Functional Safety)
    • Procedure: Execute fault injection on BMS hardware and software against FMEA; verify that each identified safety goal is met and that no single-point failure leads to an uncontrolled hazardous state
    • Standard: ISO 26262 (automotive road vehicles); IEC 61508 (general functional safety); ISO 13849 (machinery)
    • Outputs: ASIL verification; safety goal confirmation; diagnostic coverage evidence for the safety case
  • HIL to Physical Correlation
    • Procedure: Compare BMS response to defined fault scenarios on real hardware against HIL simulation results; identify discrepancies
    • Outputs: Confirmed equivalence between HIL model and physical pack; any residual gaps addressed via physical test

See also: ISO 16750, ISO 12405-3