How does ripple current affect battery life?

Besides its effect on the life time of the battery cells, the ripple current has potential benefits for the state of health diagnosis of the battery. The voltage response of the battery cells to the high frequent stimulations of the ripple current contains information of the cell’s impedance spectrum, which changes with the aging process.

Does current ripple affect battery performance degradation?

This paper documents an experimental investigation that studies the long-term impact of current ripple on battery performance degradation. A novel test environment has been designed to thermally manage the cells to 25 °C while simultaneously exciting the cells with a coupled DC and AC load profile that is representative of real-world vehicle use.

What causes a ripple in a battery?

The ripple is generated by the semiconductor switching when converting the DC voltage of the battery to AC with variable frequency and amplitude for the motors or to DC with a different voltage level (e.g., 400 V to 12 V).

What is the magnitude of a current ripple in a cell?

Cells 4–6, 7–9, 10–12 and 13–15 were electrically loaded using the same DC signal, but with the addition of an AC ripple component of magnitude: 10 Hz, 55 Hz, 254 Hz and 14.8 kHz respectively. As discussed in Section 3.1 the peak-to-peak magnitude of the current ripple was maintained constant at 1.2C.

Do alternating current profiles affect the lifetime of lithium-ion batteries?

This applies in particular for EV batteries with an expected lifetime of more than ten years. This study investigates the influence of alternating current (ac) profiles on the lifetime of lithium-ion batteries. High-energy battery cells were tested for more than 1500 equivalent full cycles to practically check the influence of current ripples.

How does current ripple affect resistance?

By comparing the EIS results presented in Fig. 8, Fig. 9, it can be seen that cells cycled with a current ripple at 14.8 kHz, experience a relatively rapid rise in R t (circa: 0.02 Ohms) between 0 and 600 cycles; the rate of rise of resistance (R t) for the same cells then reduces considerably between 600 and 1200 cycles.