What Is Calendar Life — IEC 62619?
The calendar life test is a life test in which the battery is stored for an extended period at a specified state of charge and temperature, measuring the time-dependent change in capacity and internal resistance. It represents ageing that occurs without cycling.
Purpose of Calendar Life — IEC 62619
The purpose is to determine the battery's shelf life and its performance loss in lightly used applications.
Which Products Is Calendar Life — IEC 62619 Applied To?
- Lithium-ion cells and modules
- Backup power batteries
- Electric vehicle batteries
- Energy storage systems
In Which Sectors Is Calendar Life — IEC 62619 Used?
Standards Related to Calendar Life — IEC 62619
- IEC 62619lithium battery safety in industrial applications test
Calendar Life — IEC 62619 Conditions
- State of charge (SOC)
- Fixed SOC defined in the specification (e.g. 50%, 100%)
- Storage temperature
- Reference temperature, or a higher temperature for acceleration
- Check interval
- Reference capacity measurement at specified time intervals
- Time
- Total storage period defined in the specification
Equipment for Calendar Life — IEC 62619
- Long-duration temperature chambers
- Battery test system
- Data logging system
- Safety enclosure
Sample Requirements for Calendar Life — IEC 62619
- Specimens must be brought to the defined SOC
- The initial capacity and internal resistance must be recorded
- The number of specimens is set out in the specification
- Chamber conditions must be continuously monitored throughout storage
Duration of Calendar Life — IEC 62619
It lasts as long as the storage period defined in the specification; typically on the order of months.
Calendar Life — IEC 62619 Procedure
- 1The initial capacity and internal resistance are measured.
- 2Specimens are brought to the defined SOC.
- 3They are placed in storage at the specified temperature.
- 4They are removed at defined intervals and a reference capacity measurement is performed.
- 5The change in capacity and internal resistance is plotted against time.
Calendar Life — IEC 62619 Acceptance Criteria
The acceptance criterion is a minimum capacity-retention ratio after a specified period, as given in the specification.
Evaluation of Results
Capacity loss and the increase in internal resistance are evaluated against time. A high SOC and high temperature accelerate ageing, so the storage condition directly affects the result.
Calendar Life — IEC 62619 Report
- Standard applied
- SOC and storage temperature
- Check intervals and total duration
- Capacity retention and change in internal resistance
- Time-versus-capacity graph
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- EU Battery Regulation
Batarya Testleri — What Does This Testing Field Cover?
The section below describes the field that the Calendar Life test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Battery testing answers three separate questions, each with its own body of standards: can the battery be transported, is it safe in use, does it deliver the declared performance? These three questions are often confused with one another, and the confusion has commercial consequences — a market cannot be entered with a transport report, and a shipment cannot be made with a product safety report.
On the transport side, UN 38.3 is a mandatory gate; a battery without that evidence cannot be shipped. On the safety side the application determines what applies: IEC 62133-2 for portable products, IEC 62619 and IEC 63056 for industrial and energy storage applications, UNECE R100, UL 2580 and ISO 6469 for electric vehicles. On the performance side, capacity, internal resistance, cycle life, self-discharge, charge acceptance and temperature-dependent behaviour are measured.
The distinction of LEVEL is essential in this family and is the subject that causes the most argument in the supply chain. Cell, module and pack are assessed separately; a certificate obtained for a cell does not demonstrate the conformity of the pack. Alongside the cells, the behaviour of the pack is determined by the battery management system, the cooling design, the mechanical structure, the interconnection arrangement and insulation coordination. Putting the cell supplier's report into the pack file is a common but inadequate approach.
Thermal runaway and its propagation are the most critical subject in the field. A lithium cell may enter a self-sustaining chemical reaction when damaged or overheated; at that point removing the heat from outside is usually not possible. Modern standards therefore treat thermal runaway of a single cell as an UNAVOIDABLE fault scenario and change the question: does the event propagate to neighbouring cells, what does it release outside the pack, and how much time is left for the user to escape?
In this field the battery management system is assessed not as an electronic board but as a SAFETY FUNCTION. It is shown that overcharge, overdischarge, overcurrent and overtemperature protections actually operate, that the system falls to the safe side in a fault, and that its software has been verified. In industrial and vehicle applications this assessment is tied to functional safety frameworks.
The regulatory side is becoming rapidly more demanding. Battery Regulation (EU) 2023/1542 goes beyond safety and introduces obligations for carbon footprint declaration, recovered content ratio, durability and capacity declaration, the battery passport, and removability for portable batteries. This takes the scope of testing beyond classical safety tests.
Method groups in this field
Electrical abuse
Overcharge, overdischarge, external short circuit, forced discharge and unbalanced charging. This is where it is seen whether the protection circuits actually work.
Mechanical abuse
Vibration, shock, crush, penetration, free fall and tipping. It is monitored whether internal short circuit conditions arise.
Thermal tests
Temperature cycling, thermal shock, high temperature storage, fire exposure and thermal runaway propagation.
Environmental tests
Humidity, low pressure, salt spray and, where required, immersion; these come to the fore in vehicle and outdoor applications.
Performance measurements
Capacity, energy and power, internal resistance, efficiency, cycle life, calendar life and temperature-dependent behaviour.
BMS verification
Verification of protection thresholds, the cell balancing function, communications and fault response.
Commonly confused in this field
- UN 38.3 is not a product safety certificate; it only demonstrates transport conformity.
- A cell certificate does not demonstrate pack conformity. The pack is assessed separately with its own architecture.
- Two packs built from the same cell give different results; cooling, interconnection and mechanical structure are decisive.
- A performance test is not a safety test. A cycle life report does not satisfy safety requirements.
- For an electric vehicle battery, a UL 2580 report and UNECE R100 approval are not the same thing; one is a standards assessment, the other a type approval regime.
- A vehicle battery moved into a second-life application enters a new usage profile; the earlier assessment does not carry over directly.
Which decisions these results support
- Transport conformity and the test summary for shipment
- Product safety declaration and market access
- Performance, durability and carbon footprint declarations under the Battery Regulation
- Assessing the impact of a cell supplier or BMS change
- Site acceptance processes for an energy storage system
Related Tests
Frequently Asked Questions About Calendar Life — IEC 62619
What is the difference between cycle life and calendar life?
Cycle life measures use-related ageing, while calendar life measures storage-related ageing. Real lifetime is a combination of the two, which is why specifications generally require both.