Some studies verified that the pulsed current charging technique could extend the battery lifetime and improve the charging performance of lithium-ion batteries. However, some researchers are skeptical of this opinion because their studies have not found any advantages of pulsed current charging over conventional constant current (CC) charging. Positive pulsed current (PPC), the most common pulsed current mode, was selected for the investigation in this work. The effect of the PPC with various parameters, including the duty cycle, amplitude, and frequency, on the performance and lifetime of lithium-ion batteries, are investigated by experiments. According to the experimental results, the charging speed, charging capacity, and maximum rising temperature are mainly determined by the duty cycle and amplitude of the PPC. The battery lifetime with PPC under the frequency range from 0.05 Hz to 2 kHz has been verified to be extendable. Moreover, the battery lifetime extension can even be over 100% under a specific frequency PPC compared with CC charging. This is the first work that summarizes the law of the pulse frequency on battery lifetime extension. In the future, the pulsed current is expected to be used in fast charging technologies without compromising battery lifetime.