New Energy Battery Crush Testing: Standards, Procedures, and Safety Compliance

New energy battery crush testing is a mechanical abuse test that evaluates whether lithium-ion cells, modules, and packs can withstand severe compression without catching fire or exploding. Performed in accordance with standards such as GB 38031, UN 38.3, IEC 62660, and ISO 12405, it is a mandatory safety requirement for electric vehicles and energy storage systems. This guide explains the test principles, sample types, equipment, procedures, acceptance criteria, and typical applications of battery crush testing.

Technical Overview

Crush testing (also called squeeze or extrusion testing) is one of the most important mechanical abuse tests for new energy batteries, including lithium-ion power batteries used in electric vehicles (EVs) and hybrid electric vehicles (HEVs). The test simulates severe compression scenarios such as a traffic collision, a foreign object intruding into the battery enclosure, or accidental crushing during handling and transport. Under such loads, a battery can deform beyond its elastic limit, causing separator rupture, electrode contact, and internal short circuits that may trigger thermal runaway.

During the test, the sample is compressed at a controlled speed between rigid platens or against a shaped indenter while force, displacement, voltage, and temperature are continuously monitored. The sample must not ignite or explode, although deformation, venting, and electrolyte leakage may be acceptable depending on the governing standard. Crush testing is required by regulations and standards including GB 38031, GB/T 31467.3, IEC 62660, ISO 12405-3, UN ECE R100, UN 38.3, SAE J2464, UL 1642, and UL 2580, and is typically carried out in ISO/IEC 17025-accredited third-party laboratories equipped with blast-protected test chambers.

Testing Samples

Battery Cells

Individual lithium-ion or sodium-ion cells in cylindrical, prismatic, or pouch formats are tested to characterize the intrinsic mechanical safety margin of the cell design. Cell-level crush tests usually apply a defined force (commonly 13 kN under UN 38.3, IEC 62133-2, and UL 1642) or continue until a termination condition such as a specified deformation, voltage collapse, or force threshold is reached.

Battery Modules

Modules consisting of multiple cells, busbars, and structural frames are tested to evaluate how cell-to-cell spacing, buffer materials, and module housings distribute crush loads and whether localized deformation propagates into neighboring cells.

Battery Packs and Systems

Complete high-voltage battery packs, including enclosures, brackets, thermal management components, and the battery management system (BMS), are tested to verify that the protective housing absorbs or redirects crush energy before cells are damaged. Under GB 38031 and related standards, pack-level crush tests typically apply forces of up to 200 kN using a 75 mm radius half-cylinder indenter at a squeeze speed of no more than 2 mm/s, terminating when the force reaches 200 kN or the deformation reaches one third of the overall dimension in the crush direction.

Testing Items

A typical crush test program evaluates the following parameters and observations:

• Applied crush force (kN) and force-displacement curve characteristics
• Deformation ratio in the crush direction versus the original sample dimension
• Open-circuit voltage evolution and abrupt voltage drop indicating internal short circuit
• Surface and internal temperature rise during and after compression
• Cell venting behavior, gas composition and volume, and electrolyte leakage
• Casing rupture, crack initiation, and structural collapse of the enclosure
• Occurrence of smoke, fire, or explosion during a defined observation period
• Post-test teardown analysis, including CT scanning of deformed cells

Testing Methods

Test Equipment

Crush testing is performed with a servo-hydraulic or servo-electric compression machine with a force capacity generally ranging from 150 kN to 500 kN or higher. The machine is fitted with interchangeable tooling, including flat parallel platens and cylindrical or half-cylinder indenters with a 75 mm radius, and is installed inside a reinforced explosion-proof enclosure with ventilation, gas extraction, fire suppression, remote operation, and high-speed video recording for operator safety.

Sample Preparation and Preconditioning

Before testing, samples representing series production quality are visually inspected, instrumented with thermocouples and voltage tap lines, and brought to the required state of charge, typically a high SOC (full charge or as specified by the standard) at room temperature. The worst-case crush orientation is selected, for example perpendicular to the electrode plane for cells or along the direction with the least structural resistance for packs.

Test Procedure

• Mount the sample on the lower platen and position the selected indenter in the worst-case orientation.
• Start data acquisition for force, displacement, voltage, and temperature, and begin high-speed video recording.
• Apply the compressive load at the specified speed, commonly no more than 2 mm/s for quasi-static tests under GB 38031, or at the dynamic rate defined by SAE J2464.
• Continue crushing until the termination condition is met, such as reaching the target force (for example 13 kN, 100 kN, or 200 kN depending on sample level and standard), the deformation limit, or a voltage collapse.
• Hold the position for the specified dwell period and then observe the sample, typically for one hour under GB 38031 or up to six hours under UN 38.3.
• Document results, capture the force-displacement curve, and perform post-test teardown or CT analysis if required.

Acceptance Criteria

The universal pass criterion under GB 38031-2020, ECE R100, ISO 12405-3, UN 38.3, UL 1642, and UL 2580 is that the sample must not catch fire and must not explode during compression or within the subsequent observation period. Additional criteria such as enclosure integrity, leakage limits, isolation resistance, and maximum allowable temperature may apply depending on the standard and the vehicle manufacturer's specifications. Test records must demonstrate traceability of calibration, sample SOC, ambient conditions, and instrumentation.

Applications

Crush testing supports product development, regulatory compliance, and market access across the new energy industry:

• Mandatory type approval of EV traction batteries for the Chinese market under GB 38031-2020, enforced for all new electric vehicle platforms.
• International homologation under UN ECE R100 and validation testing aligned with ISO 12405-3 and IEC 62660-2 for export vehicles.
• Transport safety certification of lithium cells and batteries under UN 38.3 (Test T.6), a prerequisite for shipping by air, sea, road, and rail.
• R&D verification of cell formats, separator strength, module buffers, and pack enclosure crash structures during design iteration.
• Mechanical abuse evaluation of stationary energy storage batteries under standards such as IEC 62619 and UL 1973.
• Failure analysis, root cause investigation, and supplier quality audits following field incidents or production anomalies.

FAQ

Q: What does the crush test simulate? A: It simulates severe mechanical abuse such as vehicle collision deformation, intrusion into the battery compartment, or crushing during transport, which can produce internal short circuits and thermal runaway.

Q: What force is applied in battery crush testing? A: It depends on the sample level and standard: approximately 13 kN for cells under UN 38.3 and IEC 62133-2, typically 100 kN for battery systems under ECE R100 and ISO 12405-3, and up to 200 kN or one third deformation for packs under GB 38031 and GB/T 31467.3.

Q: What are the pass criteria? A: The primary criterion is no fire and no explosion during the test and the defined observation period. Leakage, venting, and deformation may be permitted if the applicable standard allows them.

Q: Is crush testing mandatory for electric vehicles? A: Yes. GB 38031-2020 is a mandatory national standard in China for EV power batteries, and equivalent requirements exist in ECE R100 for Europe, while UN 38.3 is mandatory for lithium battery transport worldwide.

Q: How do cell, module, and pack crush tests differ? A: Cell tests evaluate the fundamental electrochemical and mechanical safety margin, module tests assess load distribution between cells, and pack tests verify that the enclosure and structural design protect the cells under realistic vehicle-level loads.

Q: How should a testing laboratory be selected? A: Choose ISO/IEC 17025-accredited third-party laboratories with hydraulic crush rigs of sufficient capacity, calibrated force and displacement measurement, blast-protected chambers, and experience with the specific standards and battery formats involved.