EV Batteries – The New Challenges in Quality Control

India’s progress toward an electric vehicle (EV) future is both swift and admirable. The Union government has set ambitious aims and provided incentives to EV manufacturers. Several PLI incentives are devised to drive the Make in India initiative in the country. Central & state governments have also introduced tax incentives and benefits to customers buying EVs.
However, recent fire incidents involving batteries have pushed the government to devise stringent quality regulations for electric vehicles. Since October 1, 2022, the Ministry of Road Transport and Highways has resolved to increase OEM compliance with the rules outlined in AIS-156 and AIS 038 standards. These revisions include extra safety criteria for battery cells, battery management systems, onboard chargers, battery pack design, heat propagation owing to internal cell short circuits resulting in fire, and so on.
Let’s see why quality control is essential in India’s journey towards e-mobility.

Why is Quality Control important for EV Batteries?

Although lithium-ion batteries are widely established in consumer devices, there are still significant problems with batteries in electric cars. Quality criteria, such as safety and longevity, are among them, as are challenges in manufacturing large-format high-energy batteries owing to size, handling, and testing. Due to the high cost of testing equipment and the lengthy storage durations, this requires a significant financial and logistical commitment. Quality assurance in the early phases of manufacturing must be applied to eliminate back-end testing and limit quality fluctuations in high-value products.

Quality Control is essential to ensure that the battery packs and assemblies perform up to their expected standard and do not pose any concerns once the model has been rolled out. Battery testing essentially ensures:
● Minimal chances of short-circuit in the battery electrical systems.
● Minimal chances of fire hazards that may be caused by defective welding.
● Reduced warranty claims as the batteries are tested to withstand abuse.
● An accurate risk assessment by testing the battery against external working conditions and harsher-than-normal operations.

Overcoming Challenges in Quality Control

EVs are fundamentally different from typical cars and bring a unique set of problems and dangers during testing.
EV powertrains consist of three primary components: a battery pack with a battery management system, one or more traction inverters, and one or more motors with gearboxes. They are powered by Lithium-ion batteries or other emerging EV battery chemistries or e-Axles.

Let us take a look at a few of the challenges posed by EV Battery Testing for Quality Control

Challenge #1: Low Voltage Signals on the battery pack and verification of Battery Management System (BMS) functionality

EVs must adopt International Unified Diagnosis Service (UDS) protocol per ISO 14229-1. Furthermore, before testing the battery pack, the test solutions must inspect each relay switch and validate that the high-voltage interlock loop (HVIL) signal is normal. The battery management systems will next be tested. Four segments are required for BMS testing: communication, connection, safety signal simulation, and V/I/temperature verification.

Challenge #2: Implementing effective DC Internal Resistance testing

The DC Internal Resistance (DCIR) test is a method for swiftly verifying the performance of a battery pack on the production line. High current charge and discharge test equipment are required to test fast and fulfil quality criteria. The DCIR test allows users to get data from the battery pack assembly and compare it to a gold sample to rapidly identify assembly quality. The DCIR test is normally performed in accordance with the IEC 61960 standard by measuring the current and voltage differences between two loading currents.

Challenge #3: Integration Ability of Electrical Safety Tests

Because the general public is frequently the final user of battery packs, particular consideration must be given to safety standards and accompanying battery pack laws. To meet QC requirements, the battery pack must pass safety tests such as dielectric strength, insulating resistance, ground bond, leakage current, and so on. Most organizations in the sector utilize a single electrical safety analyzer to perform these safety assessments.

Customer expectations and objectives are changing, demanding a departure from standard testing methods. Customers are looking for test solutions that provide more flexibility, convenience, quick reaction time, and cost-effectiveness than ever before.
As a result, creative business models that address specific customer pain areas and hurdles will be critical to EV market success.

Blue Star E&E recognized new obstacles in testing all components of electric vehicle systems, from power packs to propulsion. We intend to approach these difficulties holistically.
We have created flexible battery testing solutions in response to industry demands, with installations executed globally by our partnering OEMs. This includes laser-based solutions that increase battery performance and help in traceability across the manufacturing chain.

Our X-Ray systems detect discontinuities and abnormalities, lowering production costs, and our state-of-the-art environmental chambers may aid in modelling battery performance under harsh circumstances in an R&D lab. For R&D applications, we also provide acoustic emission devices to identify problems’ beginning and aid in the investigation of the root causes. Our advanced interfaced metrology equipment is a flexible tool for assuring in-line quality at high throughput.

Blue Star E&E has decades of automotive testing knowledge and technologies deployed in hundreds of test cells worldwide, giving it a competitive advantage in EV and Hybrid Vehicle Testing. Blue Star E&E engineers are continually increasing the bar to meet the needs of this dynamic business, using proven technology and a lot of field expertise.