A wider electric vehicle penetration strategy demands an improvement in charging time, performance, battery life, and safety, which can be achieved through battery temperature control. A collective impact of load and ambient on the battery needs assessment for thermal management system optimization. Herein, a multiscale multidomain numerical model is utilized on ANSYS Fluent platform. Galvanostatic and constant current discharge tests are conducted for battery modelling and validation. The first of three aspects considered is the cyclic relationship between the thermal parameters. Low ambient temperature of 0 °C at 1 C discharge rate increases the heat generation rate to 50 kW m−3 which then dips to 40 kW m−3 due to rise in battery temperature. The second is the inter‐relationship among the thermal and the electrical parameters. A faster rise in battery temperature at low ambient temperature causes an elevation in the voltage and hence the electrical performance. The third is the collective impact of thermal and electrical parameters. At 0 °C ambient temperature, an increase in discharge rate from 1 to 1.5 C increases the battery capacity by at least 6%. With the establishment of the predictive performance model of the battery, this study is expected to provide a guideline for optimizing the thermal management systems.