US 10,894,485 B2Granted

Method and device for detecting SOC of battery

AssigneeContemporary Amperex Technology Co., Limited

InventorsAng Zhao, Yong Cheng, Xiaojun Yang, Jiming Du

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Abstract

Embodiments of the present invention provide a method and a device for detecting SOC of a battery. The method for detecting SOC of a battery includes: determining an initial SOC value of the battery according to a waiting time of the battery; calculating a current SOC value of the battery based on the initial SOC value and a current working current of the battery, denoting as a first SOC value. In embodiments of the present invention, the current of the battery is real-time measured and the SOC value of the battery is calculated by accumulating the current of the battery, in addition, the initial SOC value is calibrated by the waiting time, so that the error of the SOC detection result is reduced, thereby increasing accuracy of the SOC detection result.

Claims8

Dependent claims

A method for detecting state of charge (SOC) of a battery, comprising:

determining, by a battery management system, an initial SOC value of the battery according to a current open-circuit voltage of the battery, when a waiting time of the battery exceeds a preset waiting time threshold;
measuring, by the battery management system, a current working current of the battery;
and
calculating, by the battery management system, a first SOC value of the battery based on the initial SOC value and the current working current of the battery,
wherein the method for detecting SOC of the battery further comprises:
measuring, by battery management system, a voltage (Vb) of the battery when an absolute value of the current working current of the battery does not exceed 1C;
searching, by the battery management system, for an SOC value corresponding to the voltage (Vb) from a preset correspondence table of open-circuit voltage and SOC, and denoting, by the battery management system, the searched SOC value as SCOcr;
and under a condition that the current working current is positive and the first SOC value is smaller than the SOCcr, or the current working current is negative and the first SOC value is greater than the SOCcr, taking, by the battery management system, the SOCcr as a second SOC value, and replacing the first SOC value with the second SOC.

5 more elements

A battery management system, comprising:

at least one processor, and
a memory communicatively coupled to the at least one processor,
wherein the memory stores instructions executed by the at least one processor, the instructions being configured to:
determine an initial SOC value of the battery according to a current open-circuit voltage of the battery, when a waiting time of the battery exceeds a preset waiting time threshold;
measure a current working current of the battery;
and
calculate a first SOC value of the battery based on the initial SOC value and the current working current of the battery;
wherein the instructions are further configured to:
measure a voltage (Vb) of the battery when an absolute value of the current working current of the battery does not exceed 1C;
search, by the battery management system, for an SOC value corresponding to the voltage (Vb) from a preset correspondence table of open-circuit voltage and SOC, and denote, by the battery management system, the searched SOC value as SCOcr;
and under a condition that the current working current is positive and the first SOC value is smaller than the SOCcr, or the current working current is negative and the first SOC value is greater than the SOCcr, take the SOCcr as a second SOC value, and replace the first SOC value with the second SOC.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/638,488Filed 30 Jun 2017
Priority: CN 2016 1 05155321 Jul 2016
Published: US 2018/0001782 A14 Jan 2018
Granted: 19 Jan 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

B60W 20/13
Controlling the power contribution of each of the prime movers to meet required power demand: in order to stay within battery power input or…
B60L 58/12
For monitoring or controlling batteries: responding to state of charge [SoC]
G01R 31/367
Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of…
G01R 31/382
Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of…