## 3 Results
### Model Validation
#### 3.1.3 Drag Coefficient  
Among the vehicles classified as L-7, very different shapes can be seen on the global market, which are characterised by distinct drag coefficients. Since L-7 vehicles are typically adopted under urban driving conditions, moderate velocities and accelerations are exploited. Therefore, the aerodynamics shared due to the chassis geometry might produce a minor contribution to the variation of the battery SoC trajectory.  
Nevertheless, very different scenarios have been selected to assess for the real effects of the drag coefficient on the real driving missions considered in this study. In fact, the drag coefficient changed, starting from a very low value of 0.35 to an extremely high 0.80, with a step of 0.05. The results produced by the model when applied to DM25 are reported in Figure 17.  
Figure 16: Comparison of the battery state of charge trajectories estimated by the model considering different saturation currents with respect to the experimental battery state of charge of DM25.  
Figure 17: Comparison of the battery state of charge trajectories estimated by the model considering different drag coefficients with respect to the experimental battery state of charge of DM25.  
It is noted that the shapes of the battery SoC and their relative final values are very distinct. In fact, the estimated trajectories start diverging after 500 s with a maximum variation of the final value fluctuating roughly between 0.665 and 0.60 (i.e., 6.5%). The latter is larger than the one occurring when the vehicle mass and saturation current are changed. As a result, it is important to consider that a very large range of variation of the drag coefficient was considered in the present analysis. In fact, drag coefficients down to 0.35/0.4 are typically related to sport cars [33] whereas values higher than 0.7 are typically representative of forries or American automobiles designed between the 1920s and 1930s [34]. Repeating the tuning operation on the entire set of driving missions, the maximum variations of the final battery SoC fluctuation were calculated between 0.5% and 6.5%, with a higher influence noticed in the driving missions featured by higher velocities. Finally, since the majority of experimental battery SoC trajectories were validated by applying a drag coefficient equal to 0.65 (see Figure 17), the latter has been set for all further analysis.  
Combined Effect of Battery Aging and Battery Pack Temperature Variation on the Residual Driving Range of a BEV  
An investigation about the realistic performance of the BEV considered in the study was performed by introducing the correction factors of (22) in the calculation of the available battery capacity.  
As a first step, a failure of BTMS was assumed in order to analyse the possible impact of the battery pack temperature on battery capacity fading, and the combined effect with different battery ageing levels was analyzed. Concerning \(\lambda_{SoH}\), two different conditions were considered as the DoD was set at 100% and at 80% (see Section 2.3). On the other hand, three different scenarios were studied for the battery pack temperature (hence \(\lambda_{t_{bp}}\)) as reported in Table 7. Each scenario included a reference temperature and a +/\(-2.5\)\({}^{\circ}\)C variation range. The temperature evolution throughout the driving mission was estimated by means of a piecewise cubic Hermite interpolating polynomial [35] method. According to the latter, the shape of battery pack temperature varied around the central reference value and within the imposed variation range.  
The results were divided in the two following sections based on the DoD assumed during the analyses, specifically a complete discharge with DoD100 and a partial discharge with DoD80.