A low-temperature storage aging test is an environmental reliability test that evaluates how materials, components, and finished products withstand prolonged exposure to sustained low temperatures. By simulating long-term cold storage, winter transportation, and extreme-climate deployment, this test reveals failure modes such as embrittlement, dimensional change, seal degradation, and electrical parameter drift before products reach the field.
Technical Overview
A low-temperature storage aging test is a laboratory-based environmental test in which a sample is held at a specified sub-ambient temperature for an extended period—typically from 24 hours to over 1000 hours—without being powered or mechanically operated. The purpose is to assess the sample's ability to endure long-term cold storage and to identify degradation mechanisms caused by low-temperature exposure, such as polymer chain stiffening, thermal contraction, and physical aging of materials.
When materials are cooled toward or below their glass transition temperature, elastomers lose elasticity, plastics become brittle, differential thermal contraction induces internal stress, and lubricants and adhesives may stiffen or crack. For electronic products, repeated or sustained cold exposure can drive solder joint stress, connector contact instability, and parameter drift, while for lithium-ion batteries it can cause capacity fade and increased internal resistance. The test is therefore a core item in environmental test sequences for automotive, aerospace, electronics, battery, and polymer material qualification.
The test is generally performed in accordance with recognized international and national standards, including IEC 60068-2-1 (Environmental testing – Test A: Cold), GB/T 2423.1, MIL-STD-810 (Method 502, Low Temperature), and JIS C 60068-2-1. Testing is commonly carried out in-house or by accredited third-party laboratories using programmable low-temperature chambers with calibrated temperature control and uniformity.
Testing Samples
Rubber and Elastomeric Products
O-rings, gaskets, oil seals, diaphragms, hoses, and vibration isolators are tested to evaluate cold flexibility, compression set, and sealing force retention after long-term cold exposure. Elastomers approaching their glass transition temperature can lose resilience, leading to leakage in service.
Plastics and Polymer Materials
Injection-molded housings, films, sheets, and composite parts are evaluated for embrittlement, shrinkage, warpage, and loss of impact strength. Long-term property behavior of polymeric materials for electrical equipment is often assessed under frameworks such as UL 746B.
Electronic Components and Assemblies
PCBAs, connectors, capacitors, relays, displays, sensors, and semiconductor devices are stored at low temperature to verify dimensional stability, insulation integrity, contact reliability, and electrical parameter drift caused by coefficient-of-thermal-expansion mismatch.
Lithium-Ion Cells and Battery Packs
Cells, modules, and battery packs are subjected to extended low-temperature storage to measure capacity retention, internal resistance growth, open-circuit voltage change, and self-discharge. Relevant frameworks include IEC 62133, UL 1642, and UL 2054.
Adhesives, Coatings, and Sealants
Bonded joints, painted surfaces, potting compounds, and conformal coatings are examined for bond strength degradation, cracking, crazing, chipping, and delamination following cold aging.
Cables, Wires, and Harnesses
Insulation and jacket materials are tested for low-temperature flexibility and resistance to cracking during post-exposure bending or winding, with procedures aligned to standards such as ISO 6722 for automotive cable.
Automotive, Aerospace, and Medical Parts
Functional components intended for cold-climate service—fuel system parts, exterior trim, actuator mechanisms, avionics subassemblies, and cold-chain medical devices or packaging—are validated for survival during storage and logistics in severe winter conditions.
Testing Items
Depending on the product type and specification, the following characteristics are typically measured before and after exposure and compared against acceptance criteria:
- Appearance: cracking, crazing, whitening, blistering, delamination, and discoloration
- Dimensional stability: linear shrinkage, warpage, and geometric tolerance change
- Mechanical properties: hardness, tensile strength, elongation at break, flexural strength, and impact strength
- Sealing performance: compression set, stress relaxation, and leakage rate for elastomeric seals
- Electrical performance: insulation resistance, dielectric withstand voltage, contact resistance, and functional parameter drift
- Battery characteristics: capacity retention, internal resistance, open-circuit voltage, and self-discharge rate
- Adhesion performance: peel strength, shear strength, and cohesive or adhesive failure modes
- Low-temperature flexibility: cold bend, cold elongation, and brittleness behavior per ISO 1432 or ASTM D1329
Testing Methods
Test Conditions
Test temperature and duration are selected according to the intended service environment, the product specification, or the governing standard. Common severity levels include:
- Temperatures: -20 °C, -25 °C, -40 °C, -55 °C, and -70 °C
- Durations: 24 h, 48 h, 96 h, 168 h, 240 h, 500 h, and 1000 h
- Temperature tolerance: typically ±2 °C to ±3 °C, as defined in IEC 60068-2-1
Test Procedure
A typical low-temperature storage aging test follows these steps:
- Baseline inspection and measurement of all specified parameters, with samples conditioned in a standard atmosphere (e.g., 23 °C ± 2 °C, 50 % ± 10 % RH per ISO 291)
- Placement of samples in the low-temperature chamber with adequate spacing for air circulation
- Ramp-down to the specified temperature, followed by a temperature stabilization period based on sample thermal mass
- Maintenance of the setpoint temperature for the specified duration, with the sample unpowered and unloaded (storage condition)
- Recovery of samples under controlled ambient conditions after exposure, as defined by the relevant standard, before post-test measurements
- Post-test inspection, repeat measurements, and evaluation of property change rates against defined acceptance criteria
Applicable Standards
Frequently referenced standards include IEC 60068-2-1 (Test A: Cold, including storage variant Test Ab and slow temperature change Test Ad), GB/T 2423.1, MIL-STD-810 Method 502, JIS C 60068-2-1, ISO 3384 for stress relaxation in compression, ISO 1432 for low-temperature flexibility, and ASTM D1329 for brittle point and low-temperature retraction of rubbers.
Applications
Low-temperature storage aging tests are widely applied across industries where products must survive prolonged cold exposure:
- Automotive and electric vehicles: validation of batteries, seals, sensors, connectors, and exterior polymer parts for -40 °C winter storage and transport
- Aerospace and defense: qualification of avionics, ground equipment, and materiel stored or deployed in extreme climates
- Consumer electronics: verification that devices tolerate unheated warehouses and winter shipping without damage
- Energy storage systems: assessment of cells and modules installed in cold-region grid and renewable installations
- Medical and pharmaceutical: confirmation of device and packaging integrity through cold-chain distribution
- Rail, marine, and polar equipment: durability demonstration for rolling stock components, shipboard hardware, and research instruments
- Research and quality control: material screening, formulation comparison, shelf-life estimation, and regulatory compliance evidence
FAQ
What is the difference between low-temperature storage and low-temperature operation tests?
In a storage test, the sample is unpowered and static, simulating warehousing or transit. In an operation test, the sample is powered and functionally exercised during exposure to verify performance in a cold environment. Standards such as IEC 60068-2-1 define distinct test variants for these purposes.
What temperature and duration should be selected?
The severity level should reflect the worst-case storage environment defined in the product specification. For general industrial and automotive products, -40 °C for 48 h to 96 h is common; for long-term storage life validation, durations of 500 h to 1000 h may be specified.
What are the typical failure modes?
Common failures include polymer embrittlement and cracking, seal leakage from loss of elasticity, adhesive or coating delamination, dimensional distortion, solder joint damage, contact resistance increase, insulation degradation, and battery capacity fade with rising internal resistance.
How are results judged?
Pass criteria are defined by the product standard or customer specification, typically limiting allowable changes—for example, a maximum percentage change in tensile strength, elongation, hardness, capacity retention, or insulation resistance, together with the absence of visible cracking or delamination.
Where can this test be performed?
The test can be conducted by manufacturers with in-house environmental chambers or outsourced to accredited third-party laboratories that maintain calibrated low-temperature chambers and operate in accordance with IEC, ISO, ASTM, GB, UL, and JIS test standards.