Introduction to Battery Cell Testing

Battery cell testing is a rigorous set of evaluation procedures that assesses the electrical, thermal, mechanical, and chemical properties of individual battery cells to characterize their performance, longevity, and safety before they are assembled into larger modules and packs for use in Electric Vehicles (EVs) and Energy Storage Systems (ESS).

MGA offers comprehensive battery cell testing capabilities designed to support a wide range of applications and technologies. Our laboratories are equipped to test various cell sizes and chemistries, including cylindrical, prismatic, and pouch cells, with extensive experience in materials such as NMC, LFP, and LTO. We provide a full suite of electrical and electrochemical testing services, from standardized evaluations to custom test development for emerging technologies. With over 20 years of experience in battery and EV testing, ISO 17025 accreditation, and a proven track record supporting lithium-ion and next-generation chemistries, MGA delivers precise, dependable results with rapid turnaround and high-volume capacity—all backed by expert test planning and technical support.

Cells, Modules, and Battery Packs

At the core of nearly every battery assembly is the cell. The cell is the fundamental building block of a battery, comprising of an anode, cathode, and electrolyte that enables ions to flow between the two. Most lithium-based cells have a nominal voltage of around 3.6 to 3.7 volts, and when connected in series or parallel, they form larger assemblies known as modules or packs. A module combines multiple cells to achieve a higher voltage or capacity while adding basic protection. Whereas the battery pack represents the final, fully integrated energy storage system, ready for installation in applications such as electric vehicles.

MGA's Battery Cell Testing Capabilities

Testing is the single most critical process for ensuring that battery technology is safe, trustworthy, and performs as advertised. Its role spans the entire development lifecycle, from initial material selection to final product verification. Testing types, including performance validation, lifecycle, environmental, and abuse testing, all contribute to this crucial process. Performance testing evaluates the durability, stability, and overall efficiency of the cells, while safety testing focuses on preventing failures such as thermal runaway to ensure safe operation under all conditions.

Electrical Characterization and Performance Testing

• Open Circuit Voltage (OCV) measurements: The primary purpose of OCV measurements in batteries is to accurately determine the State of Charge (SOC) and detect internal defects in the cell. OCV is defined as the potential difference across the battery's positive and negative terminals when no external load is connected and the battery is in a relaxed state (i.e., no current flowing).
• Internal resistance testing: This is a key indicator of a battery's condition, as it directly impacts its ability to deliver current, and is a primary metric for tracking degradation over time.
• Capacity testing and battery capacity verification: Used to accurately determine the actual remaining energy storage capability of a battery. Capacity testing directly calculates the battery’s State of Health (SOH). SOH represents the ratio of the battery’s current maximum capacity (the amount of charge it can hold) to its rated (nominal) capacity when new, expressed as a percentage. This is a vital function in assessing the battery’s effectiveness and lifetime.
• Performance testing and lifespan evaluation: An aging test where a battery is subjected to repeated, controlled charge and discharge cycles to simulate its usage over time. Lifespan evaluation is the broader process of predicting a battery's total usable life, which involves two distinct types of aging:

1. Cycle Life (Use-Dependent): This is determined directly by the lifecycle testing described above. It measures the life lost due to the work the battery performs (charging and discharging).

2. Calendar Life (Time-Dependent): This measures the degradation of the battery that occurs simply due to time, regardless of usage.

Safety and Abuse Testing

• Mechanical Abuse:
  
  • Nail Penetration: A destructive test used to determine the physical reaction of a cell or battery to extreme physical damage that is seen in the real-world. This test is significant for lithium-ion batteries, which can be sensitive to internal short circuits and other failures, such as thermal runaway, caused by mechanical damage.
  • Crush Testing: Like nail penetration testing, we are intentionally damaging a cell or battery by using a large hydraulic system to crush the battery to observe and record the reaction. By undergoing crush testing, manufacturers ensure that their batteries will behave safely under extreme mechanical stress, reducing the likelihood of dangerous failures and injuries in real-world scenarios.
  • Impact and Drop Testing
  • Vibe and Shock
• Electrical Abuse (Overcharge, Overdischarge, Short Circuits)
• Thermal Abuse and Thermal Runaway Testing
• Thermal Shock
• Thermal Stability
• Environmental Testing (Altitude, Humidity, Immersion, Salt Spray/Corrosion)

Battery Test Equipment and Systems

Facilities and Equipment

MGA Research Corporation operates three specialized battery test facilities across the US, located in Holly, Michigan; Burlington, Wisconsin; and Akron, New York. These facilities offer comprehensive battery testing services for cells, modules, packs, and even full vehicles, addressing the key needs of the automotive, aerospace, and energy storage industries. The battery testing conducted at these sites is diverse and designed to ensure security, functionality, and regulatory compliance. 

• Holly, MI: Focuses on cell-level abuse testing, as well as mechanical, electrical, and environmental testing on all battery sizes, including modules and pack-level. The Holly location also specializes in dynamic battery testing, including sled testing of large EV battery packs, and reproducing road profiles with their three MAST (Multi-Axis Simulation Table) tables.
• Burlington, WI: Leverages its expansive 400-acre location and automotive testing expertise for mechanical, electrical, and environmental testing on batteries of all sizes, from individual cells to packs to full vehicle thermal propagation tests in a large-volume chamber.
• Akron, NY: Houses the Technical Services Lab, and has a strong history of cell-level abuse and endurance testing and has expanded to accommodate environmental and lifecycle testing with a focus in standardized testing such as UN38.3 and UL.

MGA prioritizes safety during abusive battery testing through specialized, in-house designed facilities and rigorous protocols. Our dedicated battery testing labs are engineered to confine hazards like thermal runaway, fire, and venting using our robust containment chambers. Personnel are protected by essential PPE, including flame-resistant clothing, eye protection, high-voltage gloves, respiratory protection, insulated tools, insulated rescue hooks, isolation mats, Class D and ABC fire extinguishers, and more. Key equipment includes video surveillance and real-time data acquisition that incorporates voltage and temperature monitoring. These examples are all apart from comprehensive safety protocols meticulously designed to protect personnel, mitigate risks, and ensure the integrity of the testing environment.

Test Equipment Overview

• Battery testers and multimeters for basic measurements
• Battery test systems and automated cyclers
• Power supplies and electronic loads
• Environmental chambers
• ED shakers
• Altitude chambers
• Short circuit machine
• Salt spray chamber
• Nail pen and crush table
• Impactors and drop towers
• Shock machines
• Dust chambers and immersion tanks
• Containment chambers: MGA designs and manufactures containment systems—often referred to as containment chambers or bunkers—to safely conduct tests that are intentionally designed to cause catastrophic battery failure. The chambers are built to contain an abusive event, which can involve fire, high-pressure venting, and rupture. The bunkers are constructed using reinforced steel panels and thick concrete walls. The core purpose of the chamber is to contain a thermal runaway event (if one occurs during a test) protecting laboratory personnel and the surrounding facility.

Applications and Industries

Typical standards for EV battery testing include ISO, IEC, SAE, UL, UN and UNECE. Below are some of the common test types conducted within these standards:

• Thermal runaway propagation
• External short circuit
• Overcharge/overdischarge
• Crush/impact
• Nail penetration
• Fire resistance
• Water/dust ingress
• Vibe and shock
• Thermal cycling
• Cycle life

Automotive industry standards and specifications that MGA often performs are:

• FMVSS (Federal Motor Vehicle Safety Standards) are set by the National Highway Traffic Safety Administration (NHTSA) in the United States and describe the minimum execution requirements for all vehicles related to crashworthiness, lighting, and occupant protection
• UNECE Regulations set by the United Nations Economic Commission for Europe that cover requirements for vehicle approval, often related to safety systems, emissions, and now EV batteries (ECE R100 for electric vehicles)
• UN38.3 Testing
• UL 2580
• SAE J2464 and other automotive standards
• ISO standards for battery testing
• IEC standards for energy storage
• Regional regulatory requirements
• MIL-810

Why Battery Testing is Important

Comprehensive battery cell testing is pivotal across research, development, and mass production because it is the primary way to maintain hazard-free functionality and confirm operational integrity of the fundamental power source in electric vehicles, consumer electronics, and large-scale energy storage systems. The foremost importance of testing is risk aversion, as cells are intentionally pushed beyond normal limits to identify failure points and determine thermal stability. 

Beyond safety, testing verifies key quality metrics like capacity, energy density, and power output under various conditions, including extreme temperatures, which allows manufacturers to optimize battery design and guarantee real-world functionality.

With decades of experience and advanced capabilities across multiple chemistries and cell formats, MGA provides the expertise and precision needed to ensure your batteries meet the highest standards of performance and safety. Contact our team today to discuss your testing needs or to develop a custom testing plan tailored to your program.

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