To determine the normal operating state-of-charge (SOC) range for most hybrid electric vehicles, we should consider the typical design and operational characteristics of these vehicles. The SOC range essentially refers to the battery's charge level, and maintaining an optimal range is crucial for battery longevity and vehicle performance.
1. Option a (52% to 68%): This range is quite narrow and would limit the operational flexibility of the vehicle significantly. It is not typical for hybrid electric vehicles to have such a constrained SOC range because the vehicle would need more frequent charging or discharging cycles.
2. Option b (46% to 56%): This range is also fairly narrow and even less than Option a. Such a small range would not be efficient for the everyday use of a hybrid vehicle and would essentially make the battery use very limited, requiring the vehicle to be more reliant on its combustion engine.
3. Option c (23% to 83%): This range is quite broad and allows for a significant amount of flexibility in the operation of the hybrid system. This means that the battery can be used extensively without frequent charging cycles while maintaining a healthy SOC range for longevity.
4. Option d (15% to 95%): Although this range is broad, it pushes the lower and upper limits of the SOC to the extremes. Operating a battery at very low (near 15%) or very high (near 95%) SOC frequently can lead to decreased battery life and efficiency. Therefore, this might not be conducive for long-term use.
Given these considerations, the most suitable SOC range for the normal operating conditions of most hybrid electric vehicles is a broader range that avoids extreme lows and highs, allowing for flexible and efficient use. This makes Option c (23% to 83%) the best choice.
The answer is:
Option c. 23% to 83%
