METHOD TO ESTIMATE THE CHARGING TIME OF LITHIUM-ION BATTERIES AND CHARGING MONITOR

• US 20160209474A1
• Filed: 06/02/2015
• Published: 07/21/2016
• Est. Priority Date: 01/16/2015
• Status: Abandoned Application

• Current Assignee: Simplo Technology Incorporated (Simplo Technology STCS Limited)
• Original Assignee: Simplo Technology Incorporated (Simplo Technology STCS Limited)
• Inventors: CHEN, SHIH-CHOU, CHIU, KUAN-CHENG
• Application Number:
  US14/728,968
• Publication Number:
  US 20160209474A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0071 with a programmable schedule

Abstract

The present disclosure provides a method to estimate the charging time of a lithium-ion battery comprising: obtaining a temperature (T), a charging current (Ic) and a charging voltage (V) of the lithium-ion battery during a charging procedure, wherein during the charging procedure the lithium-ion battery is firstly charged in a constant-current charging mode (CC Mode) with a constant-current (I) and then charged in a constant-voltage charging mode (CV Mode); when the lithium-ion battery is charged in the constant-current charging mode, obtaining a constant-current charging time (tcc) and obtaining a constant-voltage full charging time (tcv) in the constant-voltage charging mode according to the temperature, so as to obtain a charging remain time of the lithium-ion battery; and when the lithium-ion battery enters the constant-voltage charge mode, obtaining a constant-voltage charging remain time (tcv′) according to the temperature and the charging current.

Claims

1. A method to estimate the charging time of a lithium-ion battery comprising:

obtaining a temperature (T), a charging current (Ic) and a charging voltage (V) of the lithium-ion battery during a charging procedure, wherein during the charging procedure the lithium-ion battery is firstly charged in a constant-current charging mode (CC Mode) with a constant-current (I) and then charged in a constant-voltage charging mode (CV Mode);

when the lithium-ion battery is charged in the constant-current charging mode, obtaining a constant-current charging time (tcc) and obtaining a constant-voltage full charging time (tcv) in the constant-voltage charging mode according to the temperature, wherein a charging remain time of the lithium-ion battery is the constant-current charging time added to the constant-voltage full charging time; and

when the lithium-ion battery enters the constant-voltage charge mode, obtaining a constant-voltage charging remain time (tcv′

) in the constant-voltage mode according to the temperature and the charging current, wherein the charging remain time of the lithium-ion battery is the constant-voltage charging remain time.

2. The method to estimate the charging time of the lithium-ion battery according to claim 1, wherein in the step of when the lithium-ion battery is charged in the constant-current charging mode obtaining the constant-voltage full charging time (tcv) in the constant-voltage charging mode according to the temperature, the temperature corresponds to a current curve charging in constant-voltage (CV curve), the current curve charging in constant-voltage corresponds to the constant-voltage full charging time.

3. The method to estimate the charging time of the lithium-ion battery according to claim 1, wherein in the step of obtaining the constant-voltage charging remain time (tcv′

) in the constant-voltage charge mode, establishing a constant-voltage charging look-up table, utilizing the constant-voltage charging look-up table to find out the constant-voltage charging remain time corresponding to the present temperature and the present charging current.

4. The method to estimate the charging time of the lithium-ion battery according to claim 3, wherein when the present temperature and the present charging current is not stored in the constant-voltage charging look-up table, utilizing interpolation or extrapolation with the constant-voltage charging look-up table to calculate the constant-voltage charging remain time (tcv′

) corresponding to the present temperature and the present charging current.

5. The method to estimate the charging time of the lithium-ion battery according to claim 1, wherein the step of obtaining the constant-voltage charging remain time (tcv′

) in the constant-voltage mode comprises;

obtaining a current curve charging in constant-voltage of the lithium-ion battery in the constant-voltage charging mode at the temperature; and

obtaining the constant-voltage charging remain time (tcv′

) according to the current curve charging in constant-voltage and the charging current.

6. The method to estimate the charging time of the lithium-ion battery according to claim 1, wherein the step of obtaining the constant-current charging time (tcc) in the constant-voltage charging mode comprises:

obtaining a charged capacity of the lithium-ion battery charged in the constant-voltage charging mode at the temperature, wherein the charged capacity is approximated by the relation equation X=pcv*I, and a corresponding charged capacity look-up table is established accordingly, wherein pcv is a slope, I is the constant current;

utilizing the constant current to find out the slope according to the charged capacity look-up table; and

calculating the constant-current charging time according to the slope by using the following equations,

RC=FCC−

X;

tcc=(RC/I−

pcv);

wherein RC is an electric capacity to be charged to the lithium-ion battery from the present time to the time of already fully charging the lithium-ion battery, tcc is the constant-current charging time, FCC is a rated capacity of the lithium-ion battery.

7. A charging monitor, used for monitoring a charging remain time of a lithium-ion battery during a charging procedure, the charging procedure comprising charging in a constant-current charging mode (CC Mode) with a constant-current (I) and then charging in a constant-voltage charging mode (CV Mode), the charging monitor comprising:

a temperature sensor, sensing a temperature (T) of the lithium-ion battery;

a current sensor, sensing a charging current (Ic) of the lithium-ion battery;

a computing unit, electrically coupling with the temperature sensor and the current sensor, the computing unit calculating the charging remain time of the lithium-ion battery during the charging procedure;

wherein when the lithium-ion battery is charged in the constant-current charging mode, the computing unit obtaining a constant-current charging time (tcc) and obtaining a constant-voltage full charging time (tcv) in the constant-voltage charging mode according to the temperature, wherein the charging remain time of the lithium-ion battery is the constant-current charging time added to the constant-voltage full charging time;

when the lithium-ion battery enters the constant-voltage charge mode, the computing unit obtaining a constant-voltage charging remain time (tcv′

) according to the temperature and the charging current, wherein the charging remain time is the constant-voltage charging remain time;

a storage unit, electrically coupling to the computing unit, the storage unit storing the relationship between the charging current and the constant-voltage charging remain time during the constant-voltage charging mode; and

a display unit, electrically coupling to the computing unit, the display unit controlled by the computing unit for displaying the charging remain time of the lithium-ion battery.

8. The charging monitor according to claim 7, wherein the relationship between the charging current and the constant-voltage charging remain time (tcv′

) stored in the storage unit is a current curve charging in constant-voltage, the current curve charging in constant-voltage is used to calculate the constant-voltage charging remain time (tcv′

) corresponding the present temperature and the present charging current.

9. The charging monitor according to claim 7, wherein the storage unit stores the charging current and the constant-voltage charging remain time (tcv′

) as a constant-voltage charging look-up table, the constant-voltage charging look-up table is used to find out the constant-voltage charging remain time (tcv′

) corresponding to the present temperature and the present charging current.

10. The charging monitor according to claim 9, wherein when the present temperature and the present charging current is not stored in the constant-voltage charging look-up table, utilizing interpolation or extrapolation with the constant-voltage charging look-up table to obtain the constant-voltage charging remain (tcv′

) time corresponding to the present temperature and the present charging current.

11. The charging monitor according to claim 7, wherein the storage unit stores the information of a charged capacity (X) of the lithium-ion battery charged in the constant-voltage charging mode at the temperature, the information of the charged capacity is presented by a function of the constant current or a charged capacity look-up table.

12. The charging monitor according to claim 7, wherein the computing unit calculates the constant-current charging time (tcc) by following steps:

obtaining a charged capacity of the lithium-ion battery charged in the constant-voltage charging mode at the temperature, wherein the charged capacity is approximated by the relation equation X=pcv*I, and a corresponding charged capacity look-up table is established accordingly, wherein X is the charged capacity, pcv is a slope, I is the constant current;

utilizing the constant current to find out the slope according to the charged capacity look-up table; and

calculating the constant-current charging time according to the slope by using the following equations,

RC=FCC−

X;

tcc=(RC/I−

pcv);

wherein RC is an electric capacity to be charged to the lithium-ion battery from the present time to the time of already fully charging the lithium-ion battery, tcc is the constant-current charging time, FCC is a rated capacity of the lithium-ion battery.