Abstract: A battery management system for an electric vehicle is provided. The battery management system may include a battery pack and a battery controller. The battery controller may acquire a first reading of the battery pack in response to first criteria being met, acquire a second reading of the battery pack in response to second criteria being met, and determine an estimated capacity of the battery pack. The battery controller may further validate the estimated capacity in response to third criteria being met. In one example, the capacity of cells is updated in a closed loop manner where both the new learned values and old valid value are engaged. The different learned values of capacity values are adaptively averaged based on the battery conditions such as temperature, accuracy of learned values, time since last update and depth of aging. The proposed methodology updates capacity in a periodic manner where different operation conditions are accommodated to facilitate capacity estimation.

Abstract: A system and method for battery management of a vehicle is provided. The battery management system may include a battery cell or pack; a contactor and a battery controller. The contactor may be connected to the battery cell or pack. The battery controller may be connected to the battery cell or pack and the contactor. The battery controller may acquire a first measurement of the battery in response to a Keyoff event after disconnection of the contactor. The battery controller may also acquire a second measurement of the battery in response to a Keyon event before connection of the contactor. The battery controller may determine an open circuit voltage (OCV) of the battery cell or pack based on the first and second measurements. For example, the acquired OCV may be used to estimate SOC of the battery and may be used to calibrate the SOC estimation algorithm or other algorithms. The battery controller may also use the acquired measurements to identify the battery model parameters.