The rapid advancement of electric vehicle (EV) technology has led to significant improvements in battery management systems (BMS) and battery design. While cell-to-pack (CTP) technology aims to increase energy density by eliminating traditional modules, modular battery systems retain key advantages in the evolving e-mobility landscape.
Advantages of Modular Batteries
Modular battery systems offer flexibility and sustainability. By organizing smaller cells into modules, manufacturers create adaptable building blocks with high functional integration. For example, BorgWarner’s Gen3 NMC (Nickel Manganese Cobalt) solution uses 21700 cylindrical cells to create modules that integrate energy storage, sensing, balancing, cooling, safety functions, and structural strength. This modular approach allows for scalable packs, such as the 9 AKM CYC system with up to 100 kWh, adjustable by adding or removing modules.
Modularity supports sustainability by encouraging reversible installation methods, reducing reliance on adhesives and potting, and enhancing remanufacturing and recycling feasibility. This design consideration is increasingly important in a world prioritizing environmental responsibility.
Industry Innovations
The industry balances modularity and larger cell formats through approaches like CTP design. BorgWarner’s new LFP battery family uses large blade cells and LFP chemistry to create multiple pack geometries for various vehicle types, from buses to off-road machinery. This modular approach within a CTP framework enhances development and production efficiency.
This convergence of modularity and cell innovation reflects the industry’s drive for solutions that balance energy content, cost-efficiency, and application coverage. Commercial vehicles benefit from such flexibility, given their diverse operation and space demands, and the need for cost parity with diesel-powered alternatives, especially considering the total cost of ownership (TCO).
Engineering Trade-Offs
Designing battery modules involves trade-offs. Modules add structural components and occupy space, slightly reducing overall energy density compared to CTP systems. However, this is offset by easier integration of advanced sensing and thermal management technologies.
For instance, BorgWarner’s Gen3 NMC modules combine mechanical stability and cooling within a single extruded profile, minimizing parts and simplifying pack assembly and scalability. Similarly, LFP blade cell systems streamline cooling solutions to a single cooling plate, reducing internal complexity and enhancing efficiency.
Safety remains a paramount concern in module design. BorgWarner incorporates multi-level safety mechanisms, from cell-level features like pressure-activated current interrupt devices to module-level thermal propagation barriers. These measures ensure robust performance across a range of applications, from light commercial vehicles to heavy-duty trucks.
Future of Modular Batteries
Looking ahead, modular battery technologies will remain relevant in response to industry demands for sustainability and versatility. While larger cells and CTP designs offer cost, energy, and power density benefits, potential shifts in cell chemistry, such as all-solid-state batteries, could renew interest in highly modular systems.
For now, the balance between modularity and innovation is epitomized by solutions like BorgWarner’s Gen3 NMC and LFP systems. These technologies demonstrate that thoughtful engineering can address the complex trade-offs of energy density, safety, and flexibility, ensuring that EVs remain competitive and sustainable across a wide range of applications.
By embracing modular design principles alongside cutting-edge advancements, the industry is not only optimizing EV performance but also paving the way for a greener, more adaptable transportation future.
