The 'Cell to Pack mass ratio' is a measure of the weight of the individual cells within a battery pack relative to the weight of the pack as a whole. It is typically expressed as a percentage, and is used to compare the weight of the cells to the weight of the pack's other components, such as its protective casing, wiring, and battery management system.
This is an important consideration in the design of battery packs, as it can impact the overall performance and efficiency of the pack. A high cell to pack mass ratio indicates that the weight of the cells is a significant proportion of the total weight of the pack, which can be beneficial in applications where weight is a critical factor, such as in electric vehicles (EVs) or portable electronic devices.
For example, the Tesla Model 3 is a mid-sized EV with a range of up to 358 miles (575 km) on a single charge. The battery pack used in this vehicle is believed to have a cell to pack mass ratio of around 70%, which means that the cells make up around 70% of the total weight of the pack.
There are a number of factors that can affect the cell to pack mass ratio of a battery pack, including the type of cells used, the design of the pack, and the efficiency of the battery management system. Researchers and engineers are continually working to improve the cell to pack mass ratio of batteries in order to increase their range and performance.
Image courtesy: Nissan Leaf