## 2 Experimental Preparation for Fuzzy Logic Application
### Battery Charging Current
\[F_{rr}=\left[C_{rr,front}m_{f}+C_{rr,back}\left(1-m_{f}\right)\right]m_{vg}cos\alpha \tag{3}\]  
where \(C_{rr}\) is the rolling coefficient, \(m_{f}\) is the weight coefficient on the front axle, \(m_{v}\) is the total weight (kg), and \(g\) is the gravity acceleration (m/s\({}^{2}\)). \[P_{b,int}=n_{M/G}V\Bigg{[}n_{t}n_{f}\left(kf_{b}\left(F_{aero}+F_{rr}+\left(m_{ v}+4\frac{I_{w/t}}{r^{2}}\right)a_{x}\right)I_{driving\ moment}\frac{N_{t}^{2}N_{f}^{2}}{r_{r}^{2}a_{x}} \right)+I_{M/G}\frac{N_{t}^{2}N_{f}^{2}}{r_{r}^{2}a_{x}}\Bigg{]} \tag{4}\]  
where \(n_{M/G}\) is the motor-generator efficiency ratio, \(r_{r}\) is the transfer rate, \(n_{t}\) is the transfer efficiency, \(n_{f}\) is the axle efficiency, \(a\) is the variable acceleration (m/s\({}^{2}\)), \(k\) is the regenerative braking coefficient, \(f_{b}\) is the coefficient of braking friction, \(I_{M/G}\) is the motor-generator moment of inertia (\(kg\).\(m^{2}\)), and \(P_{b,\ int}\) is the power transferred to the hybrid storage system (kW). Based on these formulas, the energy to be obtained from regenerative braking can be calculated; however, since this energy varies continuously depending on the road condition in EVs, certain scenarios should be determined first. In the first scenario, it is assumed that the vehicle is traveling at 120 km/h and brakes for 12 s after noticing the red lights. Because there is no slope in this scenario, the energy that the EV will obtain from regenerative braking can be calculated by calculating the kinetic energy. First, using the aerodynamic drag resistance force (2), we calculated that the vehicle consumes 5.25 kWh of energy against the drag resistance. The rolling resistance (3) for dry ground is calculated as 15.22 kWh. The kinetic energy of the EV at 120 km/h is 0.316 kWh. In addition to this kinetic energy, the kinetic energy of wheel rotation must be added. The tire size of the EV used in the study is 235/50/19, and the total tire weight is 30 kg. Based on this data, the total rotational kinetic energy for the four wheels is 0.25 kWh. Thus, the total regenerative braking energy will be 0.566 kWh. The regenerative braking energy for EVs with 80% drivetrain efficiency [48] would be 0.452 kWh. A total of 1627.2 kJ of energy would be stored within the vehicle's total braking time of 12 s. This will result in a peak power of 108.480 kW. With 80% powertrain efficiency in the vehicle, the peak power value will be 86.784 kW. If this power is divided first by the total battery voltage of 400 V and then by 48 parallel-connected battery cells, a charging current value of 4.52 A per cell will be found. This value corresponds to 1.558 C (4.52/2.9 = 1.558) for a 2900 mAh capacity battery. In the second scenario, a vehicle traveling at 50 km/h is assumed to be driving in the city. In this drive, 0.0756 kWh of energy will be stored during a full stop, and 0.065 kWh of energy will be recovered from regenerative braking with 80% powertrain efficiency. This complete stop will require 5 s of braking. Repeated 100 times for 100 km of city driving, a total of 6.5 kWh of energy will be stored. For an EV with 16.7 kWh energy consumption per 100 km, this energy will provide a gain of 38.9 km. In this scenario, 197.9 kJ of energy will generate a charging current of 2.061 A per battery cell. This value corresponds to 0.710 C for a 2900 mAh capacity battery. In the last scenario, the regenerative braking energy that will occur when the vehicle descends from 650 m above sea level to sea level is calculated. Considering the total road length of 15 km, the road slope will be 4.33%. Assuming that the vehicle descends this slope at a speed of 80 km/h, 0.26 kWh of energy will be gained. If this process is repeated five times along the road, a total of 1.3 kWh of energy will be recovered from regenerative braking. In this scenario, a charging current of 2.27 A per battery cell will be generated. This corresponds to a value of 1.277 C for a 2900 mAh capacity battery. In all these scenarios, the vehicle weight and the driver were calculated.