Volume 11 Issue 3 ( September 2024)

This study investigates the structural protection level of battery packs for two-wheeler electric vehicles due to vibration exposure. The research comprises two phases: first, an exploration of resonance frequencies in both the fixture and the battery pack, followed by vibration testing using the UN ECE R136 test profile encompassing a frequency range of 7-200 Hz and acceleration between 10-80 m/s². These tests are designed to emulate the vibration exposure experienced by two-wheeler electric vehicle batteries during typical operation. The vibration cycle is repeated seven times, and after each cycle, an assessment of the battery pack structure is conducted, utilizing a 72 Volt 20 Ah Li-ion electric motorcycle battery pack as a test sample. The results reveal that the battery pack suffered resonances at 28 Hz, resulting in an acceleration amplification exceeding 40% of the applied vibration exposure and a total force of up to 226.95 N pressing on the battery structure. The resonance severely damages all four elastic foundations and the BMS holder supporting the upper battery structure. These findings emphasize the imperative for further research into battery pack structures for two-wheeler electric vehicles capable of withstanding resonance in all testing conditions, ensuring the battery pack's safety and durability.

Keywords: Lithium Ion; Vibration Test, Resonance; Acceleration Amplification