Battery temperature derivative charging

• US 6,388,427 B1
• Filed: 09/10/2001
• Issued: 05/14/2002
• Est. Priority Date: 09/10/2001
• Status: Expired due to Fees

• Current Assignee: Space Systems/Loral Incorporated (Loral Space and Communications Incorporated)
• Original Assignee: Space Systems/Loral Incorporated (Loral Space and Communications Incorporated)
• Inventors: Levine, Erik L.
• Primary Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US09/950,445
• Time in Patent Office: 246 Days
• Field of Search: 320/150, 320/151, 320/152, 320/153, 429/61, 429/90, 429/49, 429/50, 429/52
• US Class Current: 320/151
• CPC Class Codes: H01M 10/345 Gastight metal hydride accumulators
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method of charging a nickel-hydrogen battery which includes a positive electrode, a negative electrode and an electrolyte, after the battery has been subject to discharge is disclosed the method comprising the steps of: (a) subjecting the battery to a high charge rate for a period until the battery temperature increases at least ΔT₁ over the local minimum battery temperature; (b) switching the battery charge level to a lower rate of charge than in step (a) for a period until the battery temperature increases at least ΔT₂ over the local minimum battery temperature; (c) switching the battery charge level to a much lower rate of charge than step (b) for a period up to about 30 to 60 minutes before the next scheduled eclipse; and thereafter (d) switching the battery to a pulse charge equivalent to the high charge rate of step (a).

Claims

1. A method of charging a nickel-hydrogen battery which includes a positive electrode, a negative electrode, and an electrolyte, after the battery has been subject to discharge, the method comprising the steps of:

(a) subjecting said battery to a high charge rate for a period until the battery temperature increases at least Δ

T₁, where Δ

T₁ is about 2°

C., over the local minimum battery temperature;

(b) switching the battery charge level to a lower rate of charge than in step (a) for a period until the battery temperature increases at least Δ

T₂, where Δ

T₂ is about 2°

C., over the local minimum battery temperature;

(c) switching the battery charge level to a trickle rate which is lower than step (b) for a period up to about 30 to 60 minutes before a next scheduled eclipse; and

thereafter

(d) switching the battery to a pulse charge equivalent to the high charge rate of step (a).

2. A method of charging a nickel-hydrogen battery in accordance with claim 1 wherein the battery minimum temperature is limited during both steps (a) and (b) to a temperature of T₁, wherein T₁ is a temperature in the range of about −

30°

C. to −

10°

C.

3. A method of charging a nickel-hydrogen battery in accordance with claim 1 wherein the battery temperature after step (b) is raised to a temperature of T₂, wherein T₂ is a temperature in the range of about −

10°

C. to about +5°

C.

4. A method of charging a nickel-hydrogen battery in accordance with claim 1 wherein said high charge rate of step (a) is about C/15, wherein C is the normal baseline or nameplate charge capacity of the battery.

5. A method of charging a nickel-hydrogen battery in accordance with claim 1 wherein the battery charge level of step (b) is about ½

the battery charge level of step (a).

6. A method of charging a nickel-hydrogen battery in accordance with claim 1 wherein the battery charge level of step (b) is about C/30, wherein C is the normal baseline or nameplate charge capacity of the battery.

7. A method of charging a nickel-hydrogen battery in accordance with claim 1 wherein the battery charge level of step (c) is about C/100, wherein C is the normal baseline or nameplate charge capacity of the battery.

10. A nickel-hydrogen battery charged by the method of claim 1.

8. A method of charging a nickel-hydrogen battery which includes a positive electrode, a negative electrode, and an electrolyte, the method comprising the steps of:

(a) first subjecting the battery to a relatively high charge rate of about C/15, wherein C is the normal baseline or nameplate charge capacity of the battery for a period until the battery temperature increases about 2°

C. over the local minimum battery temperature;

(b) then switching the battery charge level to a medium level of charge rate of about C/30, wherein C is the normal baseline, or nameplate charge capacity of the battery for a period until the battery temperature increases about 2°

C. over the local minimum battery temperature;

(c) then switching the battery charge level to a low level of charge of about C/100, wherein C is the normal baseline, or nameplate charge capacity of the battery for a period up to about 30 to 60 minutes before a next scheduled eclipse; and

(d) then switching the battery to a pulse charge equivalent to high charge rate of step (a).

9. A method of charging a nickel-hydrogen battery in accordance with claim 8 wherein the battery minimum temperature is limited during both steps (a) and (b) to a temperature of T₁, wherein T₁ is a temperature in the range of about −

30°

C. to about −

10°

C., and the battery temperature after step (b) is raised to a temperature of T₂, wherein T₂ is a temperature in the range of about −

10°

C. to about +5°

C.

11. A nickel-hydrogen battery charged by the method of claim 9.