What is a discharge curve in a lithium ion battery?

The discharge curve basically reflects the state of the electrode, which is the superposition of the state changes of the positive and negative electrodes. The voltage curve of lithium-ion batteries throughout the discharge process can be divided into three stages

What happens when a lithium ion battery discharges?

When the lithium-ion battery discharges, its working voltage always changes constantly with the continuation of time. The working voltage of the battery is used as the ordinate, discharge time, or capacity, or state of charge (SOC), or discharge depth (DOD) as the abscissa, and the curve drawn is called the discharge curve.

Is a battery voltage drop real?

So, the voltage drop is real — the measured voltage is what your load gets. The more current it draws from the battery, the lower is voltage it gets. When the battery is open you are measuring an open cell voltage. When the battery is in the system it's closed cell voltage under load.

How to detect abnormal cell voltage in a battery pack?

By applying the designed coefficient, the systematic faults of battery pack and possible abnormal state can be timely diagnosed. 2) The t-SNE technique, The K-means clustering and Z-score methods are exploited to detect and accurately locate the abnormal cell voltage.

What happens when a lithium ion battery is aging?

When the lithium ion battery is aging, the change of K value (voltage drop) is the formation and stability process of the SEI film on the surface of the electrode material. If the voltage drop is too large, there is a micro-short circuit inside, and the battery is judged to be unqualified.

How to detect a faulty battery pack?

The systematic faults of battery pack and possible abnormal state can be diagnosed by one coefficient. For the voltage abnormality, an accurate detection and location algorithm of the abnormal cell voltage are attained by combining the data analysis method and the visualization technique.