Acculon Energy

Empowering Performance: Navigating the Dynamics of Power Density in Battery Pack Design

Come along with us for Part 2 of our series, where we are exploring the importance of choosing the right battery cell for your application’s specific requirements. Today we’ll focus on power density in the cell selection process, what it is & how it impacts application-specific design considerations.

Contact: Betsy Barry
Communication Manager

Last week, we talked about the importance of choosing the right battery cell for your application’s specific requirements in the context of energy density in battery pack design. This week, we will discuss an important complement to energy density: power density.

Power density is a crucial parameter in battery pack design, and it complements energy density in shaping the overall performance and functionality of battery systems. While energy density is the amount of energy that a battery can store in a given mass/volume, power density refers to how quickly a battery can deliver or receive that energy per unit of volume/mass. It is typically measured in watts per kilogram (W/kg), or watts per liter (W/L). Power density is a less common measurement than energy density, but it is still a useful consideration in battery pack design. A battery system that has high power density, for example, can deliver large amounts of energy with respect to its volume. Below we explore other reasons why power density is an important design consideration:   

Acceleration/Deceleration: In applications like electric vehicles (EVs) and hybrid vehicles, power density is crucial for providing the necessary burst of power during acceleration. High power density allows for rapid discharge and quick delivery of energy to meet the demands of sudden acceleration or deceleration, contributing to better performance.

Charging: High power density enables fast charging capabilities, which is important for reducing charging times. Faster charging times can impact the adoption of a battery-powered application. 

High-Performance Electronics: Power density is critical in applications that require rapid and efficient power delivery, like power tools and other devices that demand quick and high current delivery.

Peak Power Demand: Certain applications, such as grid storage and backup power systems, may require high power density to meet peak power demands. This ensures that the battery can deliver the required power during these increased demands.

Emergency Power Supply: Power density is crucial in applications when batteries are used as emergency power supplies. A battery with high power density can quickly take over when the main power source fails, ensuring continuity of operations.

Thermal Management: Power density is often related to the ability of a battery to manage heat generated during rapid charge and discharge cycles. High-power density battery cells may require advanced thermal management systems to dissipate heat effectively and maintain safe operating temperatures. However, cells with high power density usually have a lower internal resistance, thus reducing the battery’s heat generation during cycling.

Along with energy density, power density is an important factor to consider during the battery cell selection process. It is especially crucial for applications that require high power output, rapid charging, & efficient
energy transfer.

Power density is important in battery pack design because it influences the ability of a battery to deliver energy quickly with a typically lower negative impact on the battery’s health. This is essential for applications that require high power output, rapid charging, and efficient energy transfer, contributing to improved overall performance and responsiveness of the battery system. Both energy density and power density considerations are crucial for designing batteries that meet the diverse requirements of various applications. Next week we’ll explore the two in tandem.