Method for evaluating performance states of automotive power batteries

[0054] Under the ambient temperature conditions of 5°C, 15°C, and 25°C, pulse discharge experiments at 0.1C, 0.3C, and 1.0C rates and pulse charge experiments at 0.1C, 0.3C rates were carried out on the same lead-acid battery. After that, the equivalent circuit model was used for fitting analysis to obtain the battery model parameters of the lead-acid battery at different temperatures and different pulse charge and discharge rates. A database of lead-acid battery model parameters and battery performance status is established, and some data are shown in Table 1.

[0055] Table 1. Battery model parameters and SOC database of lead-acid battery 1.0C rate pulse discharge experiment

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[0059] Under the ambient temperature conditions of 5°C, 15°C, and 20°C, pulse charge and discharge experiments at 0.2C, 0.3C, and 0.4C rates were carried out on the same lithium-ion battery. After that, the second-order equivalent circuit model was used for fitting analysis, and the battery model parameters of the lithium-ion battery at different temperatures and different pulse charge-discharge rates were obtained. Establish a database of lithium-ion battery model parameters and battery performance status, and some data are shown in Table 2.

[0060] Table 2 Lithium-ion battery 0.2C rate pulse charging experiment battery model parameters and state of charge SOC database

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[0063] During the operation of the real vehicle, the real-time battery model parameters can be obtained by using the least square method or the Kalman filter algorithm, and the performance status of the battery can be evaluated by comparing with the database stored in the ECU. Ohmic ...