Industry Review of xEV Battery Size Standards
This Technical Information Report (TIR) will review the global industry battery size standards for xEV vehicles to provide guidance for those developing battery powered vehicles. Including a review of the sizes and standards that are currently being developed or used for cylindrical cells, pouch (or polymer) cells, and for prismatic can cells. The lithium-ion cell will be the focus of this survey, but module and pack level size standards, where available, will also be included.
Rationale: This SAE Battery Size Standardization Information Report is intended to provide comprehensive reference and background information pertaining to global industry battery size standards for xEV vehicles.
With the introduction of the lithium-ion battery cell in 1991 the portable power industry quickly consolidated to a common form factor based on an 18mm diameter and a 65mm height (18650). This remained the de facto industry standard cell size for portable power applications until the advent of the “pouch” or “polymer” cell in the late 1990’s. Due to the relative flexibility of the pouch manufacturing process many different sizes of cells were introduced ranging from small milli ampere-hour size cells up to cells with over 100 ampere-hours. In the late 1990’s a prismatic hard packaged can cell was introduced and is being used in many xEV products in many different sizes.
Companies and system integrators have long described the value of coming to a set of standard cell sizes in order to create multiple sources and to help the battery industry drive down costs. With different vehicle architectures, different applications, different markets and uses, and different philosophies vehicle manufacturers have a wide variation in their requirements that drives different types of cells and mechanical design solutions.
The International Organization for Standardization (ISO), the Standardization Administration of China (SAC), China Automotive Technology and Research Center (CATARC), Verband der Automobilindustrie (VDA), and Deutsches Institut für Normung (DIN) are just a few of the organizations that are working on cell level standards. There are many similarities in these standards but they are also largely driven by the local automobile manufacturer’s requirements.