Recharge profile for spacecraft NI/H.sub.2 batteries
First Claim
1. A method of charging a rechargeable nickel/hydrogen battery comprising the steps of:
- (a) applying a charging current to the battery resulting in a substantially full state of charge for the battery;
(b) discharging the battery from the full state of charge thereof;
(c) after a substantially full state of charge for the battery has been achieved in step (a) and for a duration up to approximately 60 minutes before the onset of step (b), applying to the battery a boost charging current at a rate in the range of approximately C to C/20 for at least a part of that duration.
7 Assignments
0 Petitions
Accused Products
Abstract
An improved method of charging a rechargeable nickel/hydrogen battery comprises the steps of applying a charging current to the battery resulting in a substantially full state of charge, then for a period up to approximately 60 minutes before the onset of discharging, applying a boost charging current at a rate in the range of approximately C to C/20 for a duration up to approximately 60 minutes. The charging of the battery before applying the boost step may include the application of a taper charging current. Also, at the end of the taper charging step and immediately prior to the boost charge, a trickle charging current may be applied at a rate in the range of approximately C/80 to C/500. In another instance, when the battery has been charged to about 70% to 95% of a full state of charge, the linearly decreasing taper charge may be applied until a final desired recharge ratio is reached. Thereafter, up to a duration of approximately 60 minutes before the onset of discharging, the boost charging current may be applied at a rate in the range of approximately C to C/20 for part of or for the entire duration. The timed sequence of the initial high rate charge, the taper charge, the trickle charge, and the boost charge, in conjunction with proper control of battery temperature and recharge ratio has been found to increase overall battery capacity by approximately 10% to 30%.
17 Citations
20 Claims
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1. A method of charging a rechargeable nickel/hydrogen battery comprising the steps of:
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(a) applying a charging current to the battery resulting in a substantially full state of charge for the battery; (b) discharging the battery from the full state of charge thereof; (c) after a substantially full state of charge for the battery has been achieved in step (a) and for a duration up to approximately 60 minutes before the onset of step (b), applying to the battery a boost charging current at a rate in the range of approximately C to C/20 for at least a part of that duration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of charging a rechargeable nickel/hydrogen battery comprising the steps of:
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(a) applying a charging current to the battery resulting in a substantially full state of charge for the battery; (b) at about 70% to 95% of a full state of charge for the battery, initiating application to the battery of a linearly decreasing taper charge until a final desired recharge ratio is reached, the recharge ratio being the ratio of the quantity of charge as measured in ampere hours imparted to the battery to the quantity of charge as measured in ampere hours removed during a previous discharge; and (c) after step (b), applying to the battery a trickle charge current for a duration of at least approximately 30 minutes at a rate in the range of approximately C/80 to C/500 for a duration of at least approximately 30 minutes. - View Dependent Claims (11, 12)
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13. A method of charging a rechargeable nickel-hydrogen battery comprising the step of:
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(a) reaching a substantially full state of charge in a battery at a temperature T1 between approximately -10°
C. and -30°
C. which is lower than a temperature T2, in the range of approximately -10°
C. to +5°
C., at which discharge begins;(b) discharging the battery from the full state of charge thereof; and (c) after a substantially full state of charge for the battery has been achieved in step (a) and approximately 10 to 60 minutes before the onset of step (b), applying to the battery a boost charging current at a rate in the range of approximately C to C/20 for a duration of approximately 10 to 60 minutes. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
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Specification