Lithium Ion Battery Testing: Procedure, Standards & Safety

Lithium-ion battery (Li-ion) technology is paving the way for vehicle electrification, a trend that most analysts predict will accelerate in the next decade. According to Fortune Business Insights, the global lithium-ion battery market is expected to grow from $44 billion in 2021 to $193 billion by 2028.

The majority of rechargeable technology utilized today owes its longevity to lithium-ion battery technology including laptops and cellphones, yet significant investments are being made in hybrid and electric vehicles. With the increased adoption of battery-powered vehicles across the industry coupled with declining prices of Li-ion technologies, the growing demand for BATTERY TEST CHAMBERS is sure to catalyze additional research, testing, and manufacturing of these Li-ion components. 

What is Thermal Runaway in Lithium-Ion Batteries?

While Li-ion batteries are considered relatively safe among consumers, their thermal stability can be compromised under certain conditions. A process known as thermal runaway can occur when a cell within a Li-ion battery reaches an elevated temperature due to mechanical, thermal, short-circuiting, or electrochemical failure resulting in an exponential thermal cascade and ultimate loss of stability.

The resulting thermal and electrochemical energies are subsequently released into surrounding areas producing potentially catastrophic loss through fire and toxic gas release. Abuse testing of Li-ion batteries and their components is used to simulate a thermal or mechanical failure, which often results in the exothermic decomposition known as thermal runaway. 

What is Lithium Ion Battery Testing?

The primary objective of Li-ion battery testing is to ensure proper function and safety in any environment by creating similar environmental conditions in which these batteries will operate. Any number of a series of tests are performed according to industry standards from UL, SAE, IEC, and others with specific objectives including thermal abuse, heat resistance, temperature cycling, and short-circuiting under heat.

Below are some of the common test standards for primary (non-rechargeable) and secondary (rechargeable) Li-ion battery cells or modules with corresponding testing chambers used to accomplish the requirements.

Lithium Ion Battery Testing Standards

UL 1642

The UL Standard for Safety for Lithium Batteries consists of a series of electrical, mechanical, and environmental tests for a diverse assortment of user-replaceable Li-ion batteries. The general scope of UL 1642 requirements is to reduce the risk of fire or explosion when Li-ion batteries are used in a product, while also reducing the risk of injury to persons when operating products with user-replaceable Li-ion batteries.

A reach-in temperature chamber can be used for the electrical and environmental test portions of UL 1642 including short circuit testing at 60°C, heat testing of 5°C per minute to 150°C, and temperature cycling from 70°C to 20°C to -40°C in 30-minute transitions. 

UL 2054

The UL Standard for Safety for Household and Commercial Batteries pertains to battery level tests whereas all component cell level testing is covered under UL 1642. A series of electrical, mechanical, battery enclosure, fire exposure, and environmental tests are designed to validate primary and secondary batteries. Depending on the size and quantity of batteries, a reach-in or walk-in temperature chamber can accomplish the mold stress relief test at 70°C, heating test of 5°C per minute to 150°C, and temperature cycling from 70°C to 20°C to -40°C in 30-minute transitions. 

UL 2580

The UL Standard for Batteries for Use in Electric Vehicles was developed as a pass/fail standard to qualify Li-ion batteries in electric and hybrid electric vehicles. This standard consists of a variety of mechanical and electrical tests with one environmental test involving temperature cycling. A thermal shock chamber can be used to subject a fully charged electrical storage assembly to temperature extremes from 85°C to -40°C. 

IEC 62133

The Safety Requirements for Portable Sealed Secondary Cells represent a key standard for rechargeable Li-ion batteries for use in portable electronics like phones, laptops, and cameras. Like UL, IEC standards address general, safety, and transportation specifications for Li-ion cells and batteries. A reach-in temperature chamber can accomplish test portions including short circuit testing at 55°C, mold stress relief testing at 70°C, thermal abuse testing up to 130°C at 5°C per minute, and temperature cycling from 75°C to 20°C to -20°C in 30-minute transitions. 

IEC 62660-2

Secondary Li-ion cells for the propulsion of electric road vehicles – Part 2: Reliability and abuse testing includes standard test procedures and conditions for basic characteristics of Li-ion cells for use in the propulsion of electric vehicles. A temperature chamber can accomplish a variety of test standards including a thermal test of 5°C per minute to 130°C, temperature cycling from 85°C to -40°C at 1°C per minute (or 65°C to -20°C with electrical operation), and capacity discharge tests at -20°C, 0°C, 25°C, and 45°C.  

SAE J2464

Electric and Hybrid Electric Vehicle Rechargeable Energy Storage System (RESS) Safety and Abuse Testing describes a body of tests that may be used for abuse testing of vehicle rechargeable batteries to determine the response to conditions or events which are above their normal operating range. A temperature chamber can be used for thermal stability testing by increasing temperature in 5°C increments, while a thermal shock chamber would be effective for temperature cycling from 70°C to -40°C in 15-minute transitions. 

Lithium Ion Battery Safety Testing

While Li-ion battery use becomes universal across the vehicle and consumer electronic industries, each manufacturer develops its own proprietary Li-ion chemistries to enhance reliability, longevity, and cost-efficiency. Combining the unique chemical compositions with specific abuse test standards creates a challenge for test chamber manufacturers to provide effective testing equipment that is safe for both the user and facility.

The European Council for Automotive R&D (EUCAR) has defined hazard levels to assess and predict a specific level of danger associated with handling and testing batteries according to predictable events. As batteries are exposed to various test conditions outside their normal operating range, a hazard level is assigned to describe the potential event and effect. 

As the hazard level increases, environmental test chambers must be equipped with specific safety features to protect both facility and personnel. The most common features include temperature limited sheath heaters, intrinsically safe barriers, gas monitoring, pressure relief vents, fresh air blowers, fire suppression systems, and more. For example, a temperature limited sheath heater is designed to limit the surface temperature of the heater below the auto-ignition point of potential flammable gas released during a battery event. In some extreme test-to-failure scenarios, a unique protective enclosure may be necessary to isolate an explosion or catastrophic event. 

Looking for Lithium Ion Battery Testing Equipment?

Russells Technical Products develops environmental test chambers to meet specific customer requirements for battery testing to provide temperature cycling, humidity, altitude, vibration, and other factors. Contact us today to learn more about our battery test chamber capabilities and allow us to provide the best solution for your battery testing needs.  

Electric Vehicle Battery Testing

Vehicle electrification is here to stay. The latest reports suggest electric vehicles (EV) will reach 29.5% of all vehicle sales by 2030, a significant jump from 3.4% in 2021. That estimate accounts for roughly 4.7 million EVs on the road per year by the end of the decade. Some economists suggest the consolidation to EV mass adoption had already begun by late 2021, citing factors including new technology, emissions regulations, environmental considerations, cost, and a rapidly changing market as key elements toward jettisoning petroleum vehicles. As demand increases, manufacturers are eyeing advancements in battery technology to make EVs more accessible, economical, and longer-lasting. 

What is an Electric Vehicle Battery?

Unlike internal combustion engines, EVs rely on an electric traction motor powered by an onboard electric battery pack. The traction battery pack which drives the motor must be rechargeable, and the race continues to develop lighter, longer-lasting, and more efficiently charged battery packs. Part of the initiative to advance EV adoption is eliminating range anxiety, which is the fear of being stranded between charges. Some battery manufacturers today are introducing paradigm shifts in battery charging capacities, with one company demonstrating a proof of concept battery that powered an EV 752 miles without recharging. While this type of extended range relies on dual-energy chemistry, there largely remain four types of battery technology used in EVs today. 

Lithium-Ion Batteries for EVs

By far the most widely utilized battery technology in EVs today are lithium-ion batteries. These batteries are also widely used in consumer electronics and are prized for their high energy per unit mass and high energy to weight ratio. Lithium-ion batteries have demonstrated excellent energy efficiency, strong high-temperature performance, and relatively low self-discharge. Emerging manufacturers are combining low-cost and durable lithium-ion technology with high energy density lithium-ion chemistry to produce a dramatically extended EV range. However, the battery and performance life of lithium-ion batteries are subject to high-temperature degradation, combined with high production cost, difficult recycling capacity, and currently inadequate recharging infrastructure. 

Nickel-Metal Hydride 

Nickel-metal hydride (Ni-MH) batteries represented the largest percentage of batteries in EVs and hybrid-electric vehicles (HEV) in the early 2000s. Because of their wide use, these batteries paved the way for lithium-ion technologies used today. These batteries are considered generally safe, while offering reasonable specific energy and power capabilities. With the advantages of high energy density and power, reliable operating thermal properties, and cost-effective recyclable material sourcing, Ni-MH batteries demonstrated promising capabilities. However, recent advancements in battery technology have yielded lower weight and cost alternatives, rendering Ni-MH batteries essentially obsolete in EV propulsion. 

Lead-Acid

Unlike lithium-ion and Ni-MH batteries, lead-acid batteries are commonly used to supplement other energy sources in EVs today. Valued for their low cost to power ratio, safety, and reliability, lead-acid batteries continue to hold strong advantages for specific use applications. More advanced lead acid batteries are currently in development for use in commercial electric vehicles for ancillary loads. Despite their advantages, these batteries demonstrate poor cold temperature performance coupled with a limited lifespan, rendering them largely prohibited for single-source EV battery power supply. 

Ultracapacitors

Ultracapacitors have become a viable option for automotive OEMs and Tier 1 suppliers over the last few years based on their ancillary power supply for common road encounters including hill climb acceleration and regenerative braking. The unique technology enables energy storage in a polarized liquid between an electrode and electrolyte. As the liquid surface area increases, so does the energy storage capacity. Another recent advancement is the ultracapacitor-powered active roll system which electrically controls the stiffness of roll bars, allowing efficient cornering by placing an electric motor on the vehicle axles. Ultracapacitors also offer a wide temperature performance range, generating quality performance even in cold temperatures where common batteries fail to perform. 

EV Battery Testing Procedure

As advancements in EV battery technology pace EV adoption, understanding the safety, reliability, and effectiveness of EV batteries is critical to their sustained implementation. Manufacturers continue to develop enhanced battery technologies to reduce cost, increase range, and shorten charging capacity timelines to appease customer demand. Environmental test chambers provide the means to understand and implement these enhancements while bolstering consumer confidence. EV batteries are exposed to extreme environmental conditions like heat, cold, vibration, and corrosion in battery test chambers to assess real-world conditions and validation. Industry-specific and OEM EV battery testing standards help to demonstrate EV battery safety and reliability, while also revealing potential design faults in the early developmental process.

Electric Vehicle Battery Testing Standards

ISO 16750

This international standard applies to electrical vehicle systems and components by describing potential environmental stresses and test requirements recommended for the specific mounting location in or on the vehicle.

ISO 12405

Similarly, this international standard specifies test procedures for lithium-ion traction battery packs and systems for use in electrically propelled road vehicles. These procedures specifically provide determination for performance, reliability, and abuse of lithium-ion battery packs.

LV 124

This quality and reliability standard was jointly developed by German automotive manufacturers in 2013 to test electronic components in 12V electrical systems. It is widely used by European automotive manufacturers to test and validate lithium-ion batteries and powered components.

EV Battery Safety Standards for Testing

Safe EV battery test methods are critically important as advancements in technology produce higher energy densities in lithium-ion batteries. As batteries are exposed to extreme environmental conditions and stresses, potential events include overloads, malfunctions, and thermal runaways. In some cases, events in a single cell can spread throughout other cells and destroy the entire battery. 

To better address and standardize the potential risks associated with automotive battery events, the European Council for Automotive R&D (EUCAR) has significantly invested in hazard classification resulting in specific safety levels associated with key events. These range from Hazard Level 0 resulting in no effect or functional limitation, to Hazard Level 7 resulting in complete decomposition of the battery cell. Battery test chamber manufacturers comply with EUCAR hazard safety standards by advising specific safety equipment relevant to customer-specific testing. These features vary from customer to customer and are largely dependent on the EV battery composition, quantity, energy storage capacity, and proximity of the equipment to adjacent infrastructure. 

Russells Technical Products is a trusted battery test chamber manufacturer for customers in automotive, aerospace, defense, renewable energy, and more. Our battery test chambers conform to a variety of industry standards capable of testing conditions including high and low temperature, humidity, altitude, and vibration. Contact us today to learn more about our battery test chamber capabilities in both reach-in, walk-in, and drive-in configurations.