Demystifying EV Batteries

Author: Joseph Notaro, Vice President Global Sales & Marketing at Dukosi
Date: 02/20/2025

Chip-on-cell technology can monitor every cell, significantly enhancing the safety, performance, and cost-efficiency of EV batteries.

The electric vehicle (EV) is widely recognized as vital for reducing global emissions. However, mass-market adoption can be impeded by concerns regarding the safety and performance of the battery packs that power them. This article explores how advancements in battery technology are addressing these ongoing issues. Battery monitoring is a crucial aspect of ensuring the safety of battery packs, and we will discuss how Dukosi’s chip-on-cell technology greatly enhances control over the safety, reliability, and efficiency of EV battery packs while also improving cost-effectiveness.

Evolution of Modern Battery Technology

Like many new technologies, the early EV market faced several high-profile challenges related to large, high-voltage (HV) batteries that left a lasting negative impression on the public. Notable incidents of overheating due to thermal runaway—often triggered by collisions or misuse—have led to the belief that EV batteries are inherently unsafe. Additionally, the complexity of early EV batteries, which introduced numerous new components, contributed to perceptions that they were overwhelmingly complicated. This initial complexity resulted in manufacturing processes that were hard to automate, making these early batteries prohibitively expensive.

Other concerns contributing to ongoing perceptions include shipping and recycling costs, as well as battery longevity. However, battery development has progressed significantly since those early days, and current EV batteries and associated processes are vastly improved.

Safety in EV batteries has been enhanced in recent years thanks to innovations such as smart fuses, robust casing materials, and fault-isolating internal structures. Stringent testing and certification requirements now ensure that battery designs meet the highest safety standards. Advancements in battery chemistry, architecture, and manufacturing processes have reduced complexity and extended lifespans, with manufacturers now offering warranties lasting 8 to 10 years. New regulations, like the EU Battery Passport, are also addressing sustainability, transportation, and handling concerns. By providing a digital history and State of Health (SoH) record for batteries, these passports can help lower insurance and shipping costs while promoting better recycling practices at end-of-life stages.

Battery Management Systems (BMS) and Their Architectures

Battery Management Systems (BMS) play a pivotal role in ensuring battery safety, performance, and longevity. They monitor key parameters such as the voltage and temperature of battery cells and manage connections to charging networks. However, implementing these functions requires integrating wiring looms and sensors into confined spaces, which increases weight, cost, and complexity.

Traditional BMS architectures often compromise safety by placing temperature sensors at strategic points within the battery pack, monitoring groups of cells instead of individual ones. This approach can mask problems occurring in individual cells, leading to risks such as thermal runaway, which can release combustible gases and potentially start a fire.

While some recent BMS designs have incorporated wireless technology, they also introduce challenges such as RF interference and security risks. In contrast, Dukosi’s contactless architecture, known as the Cell Monitoring System, directly monitors individual battery cells, addressing many of these issues and improving safety and performance.

Dukosi’s system uses a Cell Monitor integrated into each cell to directly track voltage and temperature. The data collected is sent to a Dukosi System Hub, which connects to the BMS main processor. This innovative architecture significantly reduces the complexity of EV batteries by decreasing the wiring and component count, resulting in a tenfold reduction in the Bill of Materials (BoM).

Advantages of Dukosi’s Cell Monitoring System

The Dukosi Cell Monitoring System enhances BMS capabilities in several ways:

• Enhanced Safety: By positioning a temperature sensor on each cell, it allows for immediate identification of any cells exceeding predefined temperature thresholds, rather than waiting for heat to spread to adjacent cells.

• Secure Data Transmission: The system utilizes near-field communication to transmit data between the cell monitor chips and the System Hub, ensuring reliable communication even in challenging RF environments.

• Minimized Security Risks: By limiting the cell network to recognized cells and keeping wireless signals contained, security risks typically associated with far-field wireless systems are reduced.

• Flexible Design: The Dukosi solution effectively removes the need for traditional battery modules, allowing for more adaptable battery designs that utilize space and resources efficiently and can quickly adjust to different vehicle models and market demands.

• Lower Total Cost of Ownership (TCO): By reducing component count and improving accuracy in SoC calculations, Dukosi’s technology can enhance profitability for industries engaged in energy trading, while also lowering initial costs through fewer or smaller cells.

• Improved Safety and Recycling: When a battery pack reaches the end of its first life, the cell-level provenance information enables safe removal and evaluation of individual cells, which can lead to reduced insurance costs and optimized recycling processes.

Conclusion

Battery safety, performance, and longevity are critical factors in selecting an EV, and misconceptions in the marketplace have hindered adoption. However, modern batteries have improved significantly compared to earlier models that suffered from publicized issues. Battery Management Systems are essential for performance, and innovations such as Dukosi’s Cell Monitoring System have led to substantial advancements. By accurately monitoring each cell, these systems ensure safer battery operation while maximizing lifespan and performance.

Battery packs that incorporate cell-level monitoring are simpler and easier to manufacture, allowing for greater adaptability to various vehicle platforms. Additionally, this level of monitoring facilitates safer shipping and reduced handling costs, ultimately contributing to a lower TCO through more efficient creation, use, re-use, and recycling of battery materials. This approach helps foster a circular battery value chain.