Summary and selection suggestions: Voltage resistance (WV): safety first. Choose a rated voltage that is 1.2-1.5 times higher than the actual operating voltage, and consider voltage spikes. Capacity (C): Meet the basic requirements of energy storage and ripple suppression in the circuit. In switch mode power supplies, sometimes a lower ESR can be used to compensate for a certain reduction in capacity. ESR&Ripple Current: The Core of Performance and Reliability. They are the direct cause of capacitor self heating (temperature rise Δ T). High temperature is the "number one killer" of the lifespan of aluminum electrolytic capacitors. In high-frequency and high current applications such as switching power supplies and motor drives, it is necessary to choose models with low ESR and high fixed ripple current (such as solid aluminum electrolytic capacitors or special ultra-low impedance liquid electrolytic capacitors). Lifespan and temperature: guarantee of system reliability. It is necessary to choose automotive grade, high and low temperature long-life products. The actual lifespan can be estimated according to the formula: L2=L1 * 2 ^ [(T1-T2)/10] * 2 ^ [(Δ T1- Δ T2)/5], where T is the ambient temperature and Δ T is the temperature rise. Reducing the ambient temperature and the temperature rise of the capacitor itself can greatly extend its service life. Physical dimensions and installation: Consider PCB space and installation methods to ensure seismic design. Modern trend: Solid state aluminum electrolytic capacitors or high-performance polymer aluminum electrolytic capacitors are increasingly being used in demanding automotive power circuits such as ADAS and automotive computing platforms. They have extremely low ESR, extremely high ripple current capability, longer lifespan, and better high-temperature stability, but also higher cost. When designing, please refer to the detailed datasheet of the specific capacitor and leave sufficient performance margin to ensure reliable operation throughout the entire vehicle lifecycle.