Methods to compare the performance of starter batteries with varying chemistry
- Cooperative research project
- Partner: TGM Lightweight Solutions (TGM)
- Project duration: 2/2022 - 05/2022
Starter batteries are currently built almost exclusively on the basis of lead-acid EFB or AGM batteries. Norms and standardized tests are defined for lead-acid batteries (LABs), providing comparable data for different products [1]. However, starter batteries based on lithium-ion batteries have also been the subject of recent discussion. These batteries offer a high specific energy, high energy density, low self-discharge rate, and a high rate of charge acceptance as well as maintain their charge performance throughout their life time[2]. Furthermore, a weight reduction of approximately 50% has served as the primary motivation for users to adopt 12 V lithium-ion batteries [2]. Lithium iron phosphate (LFP) batteries are particularly considered as possible technology, as these material components are considered extremely safe [3,4] and the voltage level of four LFP cells matches the voltage level of a LAB.
However, there are currently no standards for lithium-ion starter batteries and the standards given in DIN EN 50342 [1] are explicitly designed for lead-acid batteries. As a result, there is a lack of methodology on how starter batteries made of LFP cells can also be meaningfully and resiliently compared with lead starter batteries. This project aims to introduce a test regime for the cold cranking of both technologies. The cold cranking ability of LFP batteries will be compared to LABs at different temperatures and SoCs.
[1] DIN EN 50342-1 Lead-acid starter batteries – part 1: General requirements and methods of test, 2015.
[2] Christoph Fehrenbacher, 12V Li-Ion Batteries – Ready for Mainstream Adoption, AABC Europe 2017.
[3] X. Yang, T. Liu, C. Wang, Thermally modulated lithium iron phosphate batteries for mass-market electric vehicles, Nature Energy, 2021.
[4] D. Doughty and E. Peter Roth, A general Discussion of Li-Ion Battery Safety, The Electrochemical Society, 2012, 21, 37.
[5] J. Jaguemont, L. Boulon, Y. Dubé, A comprehensive review of lithium-ion batteries used in hybrid and electric vehicles at cold temperatures, Applied Energy 164 (2016) 99–114.
