In this research, the discharge behavior of lithium-ion batteries is studied,and is expressed by the relationship between discharge voltage and
discharge time. This model uses a quadratic polynomial and a secondary Gaussian function to describe the discharge process of Lithium-ion batteries. The quadratic polynomial is used to describe the earlier part of discharge process and the secondary Gaussian function is used to compensate the differences between the polynomial and the actual observations. In compare with the observed discharge data from two
different battery makers and the combination of this two function models
show that the differences are minimal. Except for the first two minutes
of discharge process that has around 1% difference at most, the
differences for the rest of discharge process are well within 0.2%. It
shows that this model provides an accurate, yet concise, way of
describing the battery discharge behavior and may be used to predict the
voltage any time during discharge process effectively. In the future,
different operating temperatures, different discharge loads, cells from
different vendors, and pack with different configurations will be studied,
to make our model more robust and be able to be applied to various
applications.
