Industrial Technology Research Institute

Chiu-Yu Liu

Chein-Chung Sun

Shou-Hung Ling

Ying-Hao Hsu

Chung-Jen Chou

Heng-Hui Tu

A charging method for a rechargeable battery and a related charging architecture are provided. The provided charging method includes following steps. A characteristic curve of the rechargeable battery related to charge cycle vs. a residual capacity of a non-constant voltage charging stage under a warranty life limitation is provided. An expected residual capacity corresponding to a condition when a terminal voltage of the rechargeable battery reaches a limited charge voltage is found from the characteristic curve related to the charge cycle vs. the residual capacity of the non-constant voltage charging stage by using a current charge cycle count of the rechargeable battery. A real residual capacity corresponding to a condition when the terminal voltage of the rechargeable battery reaches the limited charge voltage approaches to the expected residual capacity by adjusting a charging current of the rechargeable battery.

Charging method for a rechargeable battery and charging architecture therewith

A method for estimating battery degradation is provided. In this method, a remaining capacity is obtained by looking up a device characteristic table according to a steady open circuit voltage of a battery. Besides, a constant current is provided to charge the battery, and when a terminal voltage of the battery reaches to a charging preset voltage, a constant voltage is provided to charge the battery. The transition point information at the transition from a constant current mode to a constant voltage mode, which includes a transition point estimated open circuit voltage, a transition point voltage, a transition point current and a transition point battery temperature, is analyzed based on voltage, current, temperature and capacity information measured during the charging process. A battery degradation index is calculated from the transition point information.

Method for estimating battery degradation

A method for estimating a capacity of a battery includes providing a look-up table storing data relating to a voltage and a capacity of the battery, and initializing the battery to reach an initialization state which serves as a starting point for a discharging process. The method also includes discharging the battery, from the initialization state, by a first amount of charge to reach a first state, calculating an actual capacity of the battery based on a measured amount of charge discharged from the initialization state to the first state, measuring an open-circuit voltage at the first state, obtaining a look-up capacity of the battery from the look-up table according to the open-circuit voltage measured at the first state, calculating a difference between the actual capacity and the look-up capacity, and correcting the look-up table based on the difference.

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Kaohsiung, Taiwan

Chiu-Yu Liu