## 6 Simulation Results and Discussion
### LiB Configuration with 50% Over-Design  
As explained in Section 6, another possibility to limit the charge over-current of the LiB module, is to increase the initial number of parallel stacks by 50%. With this change, as shown in Table 9, the charge current stays within the limit, but the stored energy, volume, weight, and cost increase significantly.  
As it is shown in Figure 17, with this configuration, the range is improved noticeably, which is due to the greater amount of energy stored in the batteries. Having a lower current passing through the LiB-ESS in comparison to the HEES, the cells are degraded slower and the cell temperature is also much lower. As a result, the degradation process will be much lower than the HESS.  
To compare both configurations from the volume, weight, range, and lifetime points of view, in the Tables 10 and 11 the result for the HESS and LiB-ESS are given, respectively.  
Figure 16: Capacity degradation trend versus the passable distance for LiB-ESS and HESS.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameter** & **LiB-ESS** & **HESS** \\ \hline Time for one discharge (s) & 66,259 & 66,794 \\ Range for one discharge (km) & 260.37 & 262.48 \\ Cell temperature (\({}^{\circ}\)C) & 25.65 & LiB. 25.4 & Lic: 35 \\ Number of Eq cycles for one discharge & 1.9 & 1.64 & 625.4 \\ Maximum discharge current & 20.15 & 12.26 & 451 \\ Maximum charge current & 15.16 \textgreater{} 10 & 9.7 & 572 \\ Range until end of life (km) & 410,476.15 & 480,148.35 \\ Driving time until end of life (h) & 29,015.15 & 33,940.04 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Obtained results for both the LiB-ESS and HESS.  
To summarize the obtained results for both the LiB-ESS and HESS, the results are summarized in Table 12.  
It is clear from the obtained results that using a HESS downsizes the energy storage system, yet is capable of providing enough energy and power to the vehicle to meet its demand. It is also seen that with the hybrid configuration, the lifetime is improved by more than 16%. The volume and weight decrease by 30% in comparison to the over-designed LiB-ESS.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Parameter**} & \multicolumn{2}{c}{**LiC**} & \multicolumn{2}{c}{**LiB**} & \multicolumn{2}{c}{**Total**} \\ \cline{2-6}  & **Single Cell** & **Module** & **Single Cell** & **Module** & \\ \hline Weight (kg) & 0.365 & 67.16 & 0.428 & 1520.25 & 1587.41 \\ Volume (I) & 0.216 & 39.74 & 0.196 & 696.19 & 735.93 \\ Cost (\%) & & 5 & 95 & 100 \\ \hline \hline \end{tabular}
\end{table}
Table 10: Size and cost of the energy storage system based on LiB with 50% oversizing.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Single Cell** & **Oversized LiB Module** \\ \hline Weight (kg) & 0.428 & 0.428 \(\times\) 96 \(\times\) 37 \(\times\) 1.5 = 2280.38 \\ Volume (I) & 0.196 & 0.196 \(\times\) 37 \(\times\) 1.5 = 1044.28 \\ Cost (\%) & & 144\% \\ \hline \hline \end{tabular}
\end{table}
Table 11: Size and cost of the energy storage system based on LiB with 50% oversizing.  
Figure 17: Capacity degradation trend versus the passable distance for the over-designed LiB-ESS and HESS.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **96S56P** & **96S37P + 184S1P** \\ \hline weight (kg) & 2300.92 & 1587.41 \\ volume (I) & 1053.69 & 735.93 \\ Cost (\%) & 144 & 100 \\ energy (kWh) & 392 1  \\ range (km) & 592,692.73 & 480,148.35 \\ continuous driving time (h) & 41,895.41 & 33,940.04 \\ \hline \hline \end{tabular}
\end{table}
Table 12: A summary of Tables 10 and 11.