Satellite battery reconditioning system and method
First Claim
1. A system for reconditioning a secondary battery in a space vehicle, said vehicle having a solar array source of charging current comprising:
- a secondary battery having a plurality of cells, a plurality of resistance networks each of said networks comprising a pair of substantially equal resistors wherein each of said networks is associated with a respective one of each of said cells,relay switch means for connecting one of said networks in shunt across its associated cell of said battery,temperature sensitive means for detecting the voltage of said battery and providing a control signal manifesting said battery voltage as a function of the temperature of said battery,means for regulating the flow of charging current from said solar array to said battery at a low charging rate,signalling means for receiving and transmitting signals between said space vehicle and a ground command station,means responsive to a signal from said signalling means manifesting a ground command for changing said regulating means to regulate the flow of charging current to a high charging rate, andmeans responsive to said control signal from said temperature sensitive means for changing said regulating means to regulate automatically the flow of charging current to said said low charging rate as the voltage of said battery exceeds a critical value for a given temperature.
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Abstract
Reduction of battery effectiveness due to memory effect and unequal cell voltages is minimized by a spacecraft power control system which reconditions the battery preferably just prior to eclipse seasons of a geo-stationary orbit by discharging each battery cell through a network of shunting resistors. Recharging is accomplished by a low power dissipation charging sequence. The load of the system, except for during the eclipse season, is receiving power continuously from the solar cells and during peak load requirements receives supplementary power from the battery cells. During the eclipse seasons, the system power is supplied solely by the battery cells.
90 Citations
8 Claims
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1. A system for reconditioning a secondary battery in a space vehicle, said vehicle having a solar array source of charging current comprising:
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a secondary battery having a plurality of cells, a plurality of resistance networks each of said networks comprising a pair of substantially equal resistors wherein each of said networks is associated with a respective one of each of said cells, relay switch means for connecting one of said networks in shunt across its associated cell of said battery, temperature sensitive means for detecting the voltage of said battery and providing a control signal manifesting said battery voltage as a function of the temperature of said battery, means for regulating the flow of charging current from said solar array to said battery at a low charging rate, signalling means for receiving and transmitting signals between said space vehicle and a ground command station, means responsive to a signal from said signalling means manifesting a ground command for changing said regulating means to regulate the flow of charging current to a high charging rate, and means responsive to said control signal from said temperature sensitive means for changing said regulating means to regulate automatically the flow of charging current to said said low charging rate as the voltage of said battery exceeds a critical value for a given temperature. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for reconditioning any one of a plurality of secondary batteries in a space vehicle, each of said batteries having a plurality of cells and said vehicle having a solar array source of charging current arranged to provide normally a low charge rate to each of said batteries, comprising the steps of:
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disconnecting a selected one of said secondary batteries from said solar array source, discharging the cells of said battery through a pair of resistors connected to said cells by relay switch contacts at a fixed discharge rate, generating a signal representing the voltage of said battery and transmitting said signal to a ground station, transmitting a control signal from said ground station to reconnect said selected battery to said solar source and to charge said battery from said source at a low charge rate, changing the low charge rate to a high rate by ground command when said battery voltage reaches a first selected voltage, sensing the voltage and temperature of said battery and automatically changing the high charge rate to said low rate when said battery voltage reaches a second selected value, greater than said first voltage. - View Dependent Claims (8)
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Specification