# Combination of LiCs and EDLCs with Batteries:
## 3 Results
The transient test was a constant load current of 4.5 A rising to a pulse of 10 A with a rise time of 1 us, and the results are presented in Figure 9. For SC, when the load changed from a low current load of 4.5 A to 10 A, there was a lag of about one third of a second in which SC was supplying about 5.5 A before SC started to meet the load requirement of 10 A and when the load changed back to 4.5 A. This perceived lag was observed again where it was briefly supplying about 9.8 A to the load. One very notable point to observe is that the average voltage changed when the transient occurred is about 0.27 V, which is a drop from 12.75 V to 12.48 V, which is an indication of the low internal resistance and high power density of the SC bank. In the case of HC, when the transient occurred, it also lagged slightly for about a third of a second in which it was supplying 6.7 A to the load instead of the required 10 A. During the transient period, the voltage difference of 0.41 V was observed, which is a drop from 11.79 V to 11.38 V. At the end of the pulse when the load returned to 4.5 A, the SC bank lagged again for about one-third of a second, and in this time, it was supplying about 8.5 A to the load before reaching the 4.5-A load demand; thus, an indication of the higher internal resistance and, therefore, much less power capacity of the HC bank when compared to the SC bank. Figure 8: The experimental validation of the SC and HC banks showing the discharging curves under a 3-A and a 12-A load. Figure 7: The experimental validation of the charging of (**a**) HC and (**b**) SC under a 3-A source. A further test was carried out combining both HC and SC by connecting them directly in parallel. During the ramp from 4.5 A to 10 A, the current supplied by capacitors closely matched what was demanded by the load. This was a much better response than when each of the two capacitor banks supplied the load individually, although the lag time was almost the same. The capacitors were able to switch to 8.5 A during the lag with a voltage change of 0.20 V, and when the pulse was over, the capacitors supplied 6.69 A before beginning to supply the 4.5-A load demand. This is a verification of the reduced internal resistance of the capacitor banks when they are connected in parallel, thus offering higher power capacity when compared to the individual performances previously discussed. In Table 1, the internal resistance of the HC and SC banks are 3.3 m\(\Omega\) and 1.74 m\(\Omega\), respectively, when they are connected in parallel, it is expected that the equivalent resistance becomes 1.14 m\(\Omega\); this will result in an even higher capacity than when the SC or HC banks were used separately, as observed in Figure 9. This is an indication that an effective way of using both SC and HC in the same energy storage system with many steep transients is to connect them directly in parallel, thus further supporting the topology being proposed in this research. A final test was carried out on the energy storages to see the real response of SC and HC to a realistic electronic vehicle load profile. In this case, only SC and HC were involved, and they were connected directly in parallel; therefore, the voltage across them was equal. The B&K precision 8602 electronic load was used to model the electric vehicle, and the result is presented in Figure 10. The load profile used is a modified version of the load profile obtained in previous research by [33; 37; 45], and the modification was done to increase the load demand by a factor of two in order to match the energy storage control design. The load profile lasted for a total of 390 s and contained several driving schemes that were obtained in a real-life application of an electric vehicle driving cycle, from acceleration, constant speed, deceleration, and even repeated acceleration and deceleration action.