Control method and control apparatus for secondary battery charging in constant current charging method

• US 5,627,451 A
• Filed: 02/28/1994
• Issued: 05/06/1997
• Est. Priority Date: 04/28/1993
• Status: Expired due to Term

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Takeda, Yoshiro
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/202,506
• Time in Patent Office: 1,163 Days
• Field of Search: 320/21, 320/20, 320/22, 320/23, 320/31, 320/32, 320/33, 320/35, 320/36, 320/37, 320/38, 320/39, 320/40, 320/48
• US Class Current: 320/151
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/007184 in response to battery voltage gradient
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method for controlling a secondary battery constant current charging method and a control apparatus therefor, which measures battery voltage (V), a change in battery voltage per unit time (ΔV/Δt), a decrease in battery voltage (-ΔV) from a maximum value, battery temperature (T), and/or a change in battery temperature per unit time (ΔT/Δt); and stops the battery charging when ΔV/Δt is greater than or equal to a predetermined value after the passage of a predetermined time t_S, or when ΔV/Δt and ΔT/Δt are greater than or equal to predetermined values, or when ΔV/Δt and T are greater than or equal to predetermined values, or when V is greater than or equal to a maximum value V_P, or when either the -ΔV or T is greater than or equal to a predetermined value.

Claims

1. A method for controlling a constant current battery charging method which charges a secondary battery in a short time, comprising the steps of:

measuring a change in battery voltage per unit time Δ

V/Δ

t;

measuring a change in battery temperature per unit time Δ

T/Δ

t;

stopping the battery charging when both the change in battery voltage per unit time Δ

V/Δ

t and the change in battery temperature per unit time Δ

T/Δ

t are at least as great as a predetermined change in battery voltage per unit time Δ

V_X1 and a predetermined change in battery temperature per unit time Δ

T_X, respectively.

2. A method for controlling a constant current battery charging method which charges a secondary battery in a short time, comprising the steps of:

measuring a change in battery voltage per unit time Δ

V/Δ

t;

measuring battery temperature T;

stopping the battery charging when both the change in battery voltage per unit time Δ

V/Δ

t and the battery temperature T are at least as great as a predetermined change in battery voltage per unit time Δ

V_X1 and a predetermined temperature T_X.

3. An apparatus for controlling a constant current battery charging method which charges a secondary battery in a short time, comprising:

first measuring means for measuring a change in battery voltage per unit time Δ

V/Δ

t;

second measuring means for measuring a change in battery temperature per unit time Δ

T/Δ

t;

judging means for stopping the battery charging when it is judged that both the change in battery voltage per unit time Δ

V/Δ

t and the change in battery temperature per unit time Δ

T/Δ

t are at least as great as a predetermined change in battery voltage per unit time Δ

V_X1 and a predetermined change in battery temperature per unit time Δ

T_X, respectively.

4. An apparatus for controlling a constant current battery charging method which charges a secondary battery in a short time, comprising:

first measuring means for measuring a change in battery voltage per unit time Δ

V/Δ

t;

second measuring means for measuring battery temperature T;

judging means for stopping the battery charging when it is judged that both the change in battery voltage per unit time Δ

V/Δ

t and said battery temperature T are at least as great as a predetermined change in battery voltage per unit time Δ

V_X1 and a predetermined temperature T_X.