Hughes Aircraft Company

Hughes Electronics Corporation

United States of America As Represented by the Secretary of the Air Force

Other

Steven J Stadnick

Howard H Rogers

Allen R Powers

Richard P Sernka

Walter R Oswald

John P Stafford

Robert K Taenaka

Stanley J Krause

Joseph H Hayden

Barry G Gage

Walter Rex Oswald

Susan K Ferer

David W Wong

A battery system includes an electrical storage cell having a positive terminal and a negative terminal. The electrical storage cell is provided with a normally open bypass circuit path that is closed in the event of an open-circuit failure of the electrical storage cell. The bypass circuit path includes a first electrical conductor connected to the positive terminal of the electrical storage cell, a second electrical conductor connected to the negative terminal of the electrical storage cell, and a shorting gap between the first electrical conductor and the second electrical conductor. A mass of a fusible material is positioned at an initial mass location. A heat source is activatable upon the occurrence of an open-circuit condition of the electrical storage cell. The heat source is operable to melt at least a portion of the mass of the fusible material and thereby to close the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor.

Low-voltage-drop bypass of failed battery cell

A battery system includes an electrical storage cell having a positive terminal and a negative terminal. The electrical storage cell is provided with a normally open bypass circuit path that is closed in the event of an open-circuit failure of the electrical storage cell. The bypass circuit path includes a first electrical conductor connected to the positive terminal of the electrical storage cell, a second electrical conductor connected to the negative terminal of the electrical storage cell, and a shorting gap between the first electrical conductor and the second electrical conductor. A mass of a fusible material is positioned at an initial mass location. A spring is positioned to force the mass of the fusible material from the initial mass location, along the metal flow path, and into the shorting gap, when the mass of the fusible material is at least partially molten. A heat source is activatable upon the occurrence of an open-circuit condition of the electrical storage cell. The heat source is operable to melt at least a portion of the mass of the fusible material. The spring forces the molten material into the shorting gap, where it solidifies and closes the shorting gap so that the first electrical conductor is in electrical communication with the second electrical conductor.

Low-voltage-drop, spring-activated bypass of failed battery cell

A pressurized-gas battery, such as a nickel-hydrogen battery, is rapidly charged at a high charging rate until the measured pressure reaches a high-pressure limit, and thereafter slowly charged at a reduced charging rate as the measured pressure falls toward a low-pressure limit. The high-pressure limit and the low-pressure limit each decrease with increasing temperature.

Temperature compensation of the pressure cutoff of charging of a

An energy storage cell includes a vessel having a wall with a pair of oppositely disposed apertures therethrough, and an electrochemical cell, such as a nickel-hydrogen cell, within the vessel interior. A central core extends through the oppositely disposed apertures and performs all basic electrical, compressive support, and thermal removal functions for the energy storage cell. The central core includes electrical interconnects for the plate sets of the electrochemical cell, axial compression loading supports for the plate sets, and a heat pipe or other structure for removing heat from the interior of the vessel.

Electrochemical storage cell having a central core providing mechanical,

A battery system includes an electrical storage cell having a positive terminal and a negative terminal. The electrical storage cell is provided with a normally open bypass circuit path that is closed in the event of an open-circuit failure of the electrical storage cell. The bypass circuit path includes a normally open bypass circuit path comprising a diode having a cathode and an anode. The cathode of the diode is electrically connected to the positive terminal of the electrical storage cell and the anode of the diode is electrically connected to the negative terminal of the electrical storage cell. The diode fails to a shorted current path at an imposed current less than a cell failure current, providing a low-resistance, low-voltage-drop bypass of the electrical storage cell.

Low-voltage-drop diode bypass of failed battery cell

A battery cell terminal having structure for receiving a thermal conductor. The receiving structure may comprise a bore defined by an inner surface of the terminal. The thermal conductor may be a heat pipe or other suitable conductor. A layer of electrical insulation may be disposed between the terminal and the thermal conductor. The terminal conducts heat produced by electrodes in the cell to the thermal conductor which then conducts the heat to a heat sink.

Battery cell terminal

An apparatus and method for controlling the temperature of a battery used in a spacecraft or an electric vehicle are disclosed. The apparatus includes a thermal conductor, such as a thermally-conductive heat pipe or forced-fluid cooling loop, that is in thermal contact with thermally-conductive cell terminals of the battery, and a heat sink, such as a radiator. The inventive method includes operating the battery to generate and conduct heat to the thermally-conductive battery cell terminals. The generated heat is passed via conduction from the terminals to the thermal conductor. The heat is conducted through the thermal conductor to a heat sink which may be remotely located with respect to the battery. Preferably, the thermal conductor remains electrically insulated from the battery cell terminals and the heat sink.

Method and apparatus for transferring heat generated by a battery

A nickel-hydrogen energy storage cell includes a hermetic pressure vessel having a wall made of a nickel-base alloy, and a hollow tube made at least in part of palladium and joined to the wall of the pressure vessel such that an interior of the hollow tube is in communication with an interior of the pressure vessel. A heater controllably heats at least a portion of the hollow tube to increase the diffusion rate of hydrogen through the wall of the hollow tube and thereby controllably vent hydrogen from the pressure vessel. The energy storage cell further includes at least one plate set within the wall of the pressure vessel, an electrolyte, and a pair of electrical leads extending from the at least one plate set and through an electrical feedthrough in the wall of the pressure vessel.

Energy storage cell with hydrogen vent

A battery system includes a battery cell having a cylindrical battery cell housing and a housing support external to the battery cell housing. The housing support is formed of an electrical insulator layer contacting the cylindrical external surface of the battery cell housing, and a heat conductor formed of heat-conducting fibers overlying and contacting the electrical insulator layer and aligned generally parallel to the cylindrical axis of the battery cell housing. The heat-conducting fibers are made of high-thermal-conductivity graphite and have a sink end. A fiber-reinforced composite structural support layer is applied overlying the heat-conducting fibers to force the electrical insulator layer into contact with the battery cell housing without the presence of an adhesive between the electrical insulator and the battery cell housing. A thermal sink is in thermal contact with the sink ends of the plurality of heat-conducting fibers at a first end of the cylindrical battery cell housing. A structural base joined to the structural support layer is positioned at a second end of the cylindrical battery cell housing.

Battery system with a high-thermal-conductivity integral structural

A group of electrically interconnected energy storage cells, such as nickel-hydrogen energy storage cells, is pressure balanced and its precharge reset by discharging the energy storage cells of the group to a substantially fully discharged state, venting all of the energy storage cells of the group to the same reduced internal hydrogen pressure, and thereafter discontinuing the venting. The venting occurs without recharging the energy storage cells, and after venting is complete the energy storage cells of the group are recharged.

Resetting the precharge of a group of pressurized gas energy storage

A battery reconditioning system and method for a spacecraft which utilizes a single battery as a secondary source of power for spacecraft electrical loads (10). The battery (14) includes a plurality of serially connected packs (30-36) each including a plurality of cells (40-46) connected in series. Sensors (50-56) are provided with each pack for sensing the state of charge of the pack. Battery charging circuitry (12,18,20) is controlled from control circuitry (22,52) which is responsive to the state of charge sensors as well as commands from a ground station transceiver (57). Reconditioning resistors (60-66) are adapted to be connected across the individual packs through switches (70-76) which are controlled by the control circuitry to discharge the pack at a relatively high rate when reconditioning is desired. After a pack is discharged to a desired low state of charge, its reconditioning resistor is disconnected and all packs are recharged in series. A pair of diodes (80A,80B-86A,86B) are connected across each pack and provide a low resistance current path in the event a fault clearing current is required from the battery during reconditioning of a pack.

System and method for reconditioning spacecraft battery

A battery (20) includes a battery container (22), a base (30) attached to the interior of the wall (24) of the battery container (22), a compliant first weld ring (32) extending to a first side of the base (30), and a compliant second weld ring (34) extending to a second side of the base (30). A first electrochemical storage cell stack (36) is supported on a core (42) extending from the first weld ring (32), and a second electrochemical storage cell stack (38) is supported on a separate core (42) extending from the second weld ring (34). Each of the storage cell stacks (36,38) includes a set of storage cells (40) and a gas screen (68) between each of the storage cells (40). The gas screens (68) are dimensioned to extend outwardly to contact the wall (24) of the battery container (22), thereby serving to damp vibrations in the storage cell stack (36, 38 ).

Vibration-resistant battery having individually supported storage cells

A battery system comprises a plurality of sodium-sulfur storage cells connected in series to form a battery, with voltage measurement leads attached across each of the individual storage cells. A charge-limiting circuit controllably isolates an individual storage cell from a charging current applied across the battery when the measured voltage across that individual storage cell exceeds a preselected maximum storage cell voltage. Preferably, the charge-limiting circuit includes a bypass circuit connected through the voltage measurement leads and a circuit element that becomes conductive when the voltage across the individual storage cell exceeds the preselected maximum storage cell voltage. There are a plurality of charge-limiting circuits, one for each of the storage cells of the battery. In operation, a high charging current is imposed on the battery while measuring the voltage across each individual storage cell, until the voltage measured across at least one of the storage cells exceeds a preselected reduced-current voltage that is less than the preselected maximum storage cell voltage. The charging current is thereafter reduced to a low charging current while continuing to charge the battery. The low charging current is bypassed around each of the individual storage cells as that storage cell reaches the maximum voltage, until all of the storage cells reach the same state of charge.

Charge balancing of batteries during charging

Improved nickel-hydrogen batteries (10) are disclosed, wherein the improvement provides for wettable porous polypropylene cloth gas diffusion screens (12) to separate the individual cells (16) thereof. When necessary, substantially all of the electrolyte may be readily drained from the cells (16) of the batteries (10). Wettability is achieved by oxidizing the surfaces of the cloth gas diffusion screens (12) prior to assembling them in the batteries (10).

Nickel-hydrogen cells

A deformable element is placed between the active plate sets of a storage battery to accommodate, by permanent compressive deformation, the swelling that occurs in the positive electrode of the plate set during extended cycling of the storage battery. The plate sets are normally supported on a core under axial compressive loading, and the swelling would otherwise deform or place a strain on the electrode connector leads, which could cause them to fail by shorting. The deformable element, preferably a modified polypropylene screen that permits the release of gas from the electrode and also is deformable in the direction perpendicular to the screen, compressively deforms to absorb the gradually increasing swelling of the positive electrode. The loading on the electrode connectors is thereby avoided or minimized, removing a major potential cause of failure.

Growing community of inventors

Lakewood, CA, United States of America

Steven J Stadnick