Lightweight battery enclosure design

The battery box is the heaviest part of an electric vehicle and may account for 20-30 per cent of its weight. Therefore, the design of a lightweight battery box is an important step towards the lightweight design of the entire vehicle. In this paper, a systematic procedure has been followed to reduce the weight of a given battery enclosure structure, while ensuring that the structure can withstand the stresses during acceleration, braking and turning of the vehicle, and the compressive stresses on the cells inside the enclosure do not exceed the maximum limit. The important design parameters were identified, and an optimal parameter set with respect to lightweight design and structural stability was determined. The Taguchi method of orthogonal arrays was used for the analysis to optimize the calculation efforts. The stress distribution over the body of the enclosure was analyzed and material was removed from the regions having low stress concentration. Subsequently, the structure was modified and forced air cooling was introduced to ensure that the temperature rise during operation was within acceptable limits. The stress, thermal and modal analysis of the resultant structure was then carried out to demonstrate its feasibility.