Browse Topic: Nickel-hydrogen batteries

Items (11)
Find
Improved Control of Charging Current for Ni/H BatteryTBMG-3006010/1/1999
In a proposed method of controlling the electric current supplied for charging a nickel/hydrogen battery, the rate of evolution of heat would be taken into account along with the electrical quantities (voltage, current, and/or charge as functions of time) that are traditionally taken into account. This method might also prove useful for controlling charging currents in batteries based on different chemistries.
Validation of Modified Wine-Rack Thermal Design for Nickel-Hydrogen Batteries in Landsat-7 Spacecraft Thermal Vacuum Test and in Flight1999-01-26268/2/1999
A heritage wine-rack thermal/mechanical design for the nickel-hydrogen batteries was the baseline at the Land-sat-7 Preliminary Design Review. An integrated thermal and power analysis of the batteries performed by the author in 1994 revealed that the maximum cell-to-cell gradient was 6.6°C. The author proposed modifying the heritage wine-rack design by enhancing heat conduction from cells to cells, and from cells to battery frame. At the 1995 Intersociety Energy Conversion Engineering Conference (IECEC), the author presented a paper on methods of modifying the wine-rack design [1]. It showed that the modified wine-rack option, which uses a metallic filler, could reduce the maximum cell-to-cell temperature gradient to 1.3°C, and could also reduce the maximum cell temperature by as much as 8°C. That design concept was adopted by the Landsat-7 Project Office, and a design change was made at the Critical Design Review. Results of the spacecraft and instrument integrated thermal balance (T/B) and thermal vacuum (T/V) test, and temperature data in flight show that the temperatures of the battery cells are very uniform. The maximum cell-to-cell gradient is 1.4°C. They validate the modified wine-rack thermal design.
Choi, Michael K.
The Timed Spacecraft: A Thermal Design Perspective1999-01-21337/12/1999
The Thermosphere, Ionosphere, Mesosphere, Energetics, and Dynamics (TIMED) spacecraft will be placed in a 625 km, 74.1 degree inclination low earth orbit, with four scientific instruments on board. The TIMED spacecraft will be launched from Vandenberg Air Force Base in May 2000 on a Delta II rocket. The TIMED spacecraft is a co-manifested launch with the JASON spacecraft (TOPEX follow-on). The TIMED spacecraft is encapsulated in a Dual Payload Attach Fitting (DPAF), with the JASON spacecraft mounting to the top of the DPAF. The TIMED instruments are designed to characterize the Earth’s upper atmosphere using visible, UV and IR sensors. Due to the stringent thermal requirements for the instruments, the spacecraft must maintain a Nadir pointing side, as well as, a sun keep out zone on the backside of the spacecraft. These basic requirements, along with instrument field of view requirements have resulted in a very interesting spacecraft design. The TIMED spacecraft has the subsystems on board necessary to provide the instruments with the power, attitude control and thermal stability they require. The spacecraft sports an optical bench containing four single axis gimbaled telescopes, two star trackers and two GPS antennas. The spacecraft has a 50 Amp-Hour, 22 cell Nickel-Hydrogen battery split into two halves placed on opposites of the spacecraft. The Ni-H battery is just one component on the TIMED spacecraft which requires careful thermal control. The TIMED spacecraft is implementing an Integrated Electronics Module (IEM) that contains several different spacecraft subsystems, like C&DH, S-band receiver and transmitter, solid-state recorder and more. The combination of all these subsystems into one box, normally packaged in separate card cages, has resulted in some challenging thermal design problems. This paper will discuss the thermal control approach, the thermal testing conducted to date and thermal testing to be completed for the TIMED spacecraft.
Williams, Bruce D.
Hubble Space Telescope Nickel-Hydrogen Battery and Cell Testing - An Update9290898/3/1992
Nickel-hydrogen (Ni-H2) technology has only recently been utilized in low earth orbit (LEO) applications. The Hubble Space Telescope (HST) program, over the past five years, played a key role in developing this application. The HST not only became the first reported, nonexperimental program to fly Ni-H2 batteries in a LEO application, but funded numerous, ongoing tests that served to validate this usage. The Marshall Space Flight Center (MSFC) has been testing HST Ni-H2 batteries and cells for over three years. The major tests include a 6-battery system (SBS) test and a single 22-cell battery (FSB) test. The SBS test has been operating for 34 months and completed approximately 15,200 cycles. The performance of the cells and batteries in this test is nominal. Currently, the batteries are operating at an average end-of-charge (EOC) pressure that indicates an average capacity of approximately 79 ampere-hours (Ah). The watt-hour (Wh) efficiency is averaging about 82 percent, and the end-of-discharge (EOD) voltage is remaining stable at 1.31 volts (V)/cell. The batteries have been operating for nearly 15 months since the last capacity check was run and plans are to continue cycling without a capacity check for at least another 3 months. The FSB test has been operating for nearly 33 months and completed approximately 14,700 cycles. The performance of the cells in this battery test is also nominal. Currently, the battery is operating at an average EOC pressure that indicates a capacity of approximately 79 Ah. The Wh efficiency is averaging about 82 percent, and the EOD voltage is remaining stable at 1.32 V/cell. This battery has also been operating for nearly 15 months since the last capacity check was run and plans are to continue cycling just as the SBS test for at least another 3 months before a capacity check is considered. Two special tests were conducted on the SBS and FSB over the past year. The first test required both the SBS and the FSB to be placed in a step-taper charge mode for approximately 4 months to evaluate the effects of operating the batteries in this less-efficient charge mode for an extended period of time. This test was developed in response to a possible need to free additional memory in the HST on-board computer. The electrical power system (EPS) could contribute to this end by eliminating its software-control (step-to-trickle) charge mode capability which requires significant computer memory. The results of the test showed little effect on the overall performance of the system when changed to a step-taper charge mode as long as the V/T level (temperature-compensated charge voltage cutoff curves) was lowered in conjunction with the charge mode change. The second test was an attempt to duplicate an anomaly observed on the HST EPS in which telemetry indicated 10 minutes into trickle charge a load current increase of approximately 20 amperes (A) resulting from an apparent temporary short to structure somewhere between the +CC solar panel assemblies (SPA) and the battery 1 positive lead. The current was high enough to lower the battery voltages to a point that the charge control relays closed, thus placing the batteries in a momentary high-rate charge mode. The test showed a current of approximately 70 A for less than 250 milliseconds would create such a voltage drop on the batteries. Because the telemetry rate is only two samples per second, a short pulse of this magnitude is possible and is the likely scenario for what occurred on the HST.
Brewer, Jeffrey C., Whitt, Thomas H.
Nickel Hydrogen Batteries for Terrestrial Applications9290568/3/1992
Nickel-Hydrogen (Ni-H2) batteries have an extensive database of successful operation in aerospace applications requiring long life, no maintenance, and extremely high reliability. In the common pressure vessel (CPV) design configuration, the life cycle cost of the system is actually lower than that of lead acid and other competing battery technologies. This cost advantage can be directly attributed to the long life, exceeding 10,000 deep discharge cycles, and no maintenance capabilities of the CPV Nickel-Hydrogen battery. As a result the CPV has significant market potential in terrestrial applications such as load leveling, remote energy storage, and aircraft starting.
Zagrodnik, Jeffrey P., Jones, Kenneth R.
Design of a Nickel-Hydrogen Battery Simulator for the NASA EOS Testbed9294908/3/1992
The hardware and software design of a Nickel-Hydrogen (Ni-H2) Battery Simulator (BS) with application to the NASA Earth Observation System (EOS) satellite is presented. The battery simulator is developed as a part of a complete testbed for the EOS satellite power system. The battery simulator involves both hardware and software components. The hardware component includes the capability of sourcing and sinking current at a constant programmable voltage. The software component includes the capability of monitoring the battery's Ampere-hours (Ah) and programming the battery voltage according to an empirical model of the nickel-hydrogen battery stored in a computer.
Gur, Zvi, Mang, Xuesi, Patil, Ashok R., Sable, Dan M., Cho, Bo H., Lee, Fred C.
Nickel-Metal Hydride and Silver-Metal Hydride Batteries for Aerospace Applications9294608/3/1992
Nickel and silver-metal hydride batteries are being developed for aerospace applications by Eagle-Picher. Metal hydride batteries offer a number of advantages over other aerospace battery systems. Nickel-metal hydride batteries have twice the gravimetric energy density of nickel-cadmium and twice the volumetric energy density of nickel-hydrogen. Silver-metal hydride batteries have the potential of three times the energy density of nickel-metal hydride and exhibit superior charge retention characteristics. Aerospace metal hydride batteries are hermetically sealed, operate at low pressure and are prismatic in geometry. They exhibit excellent overcharge and overdischarge capability. Preliminary calorimetry data indicates superior thermal performance as compared to nickel-cadmium and nickel-hydrogen batteries. Some initial AC impedance spectroscopy work has been completed on both metal-hydrogen and metal-hydride battery systems. The objective of current programs at Eagle-Picher is to develop high energy density, long cycle life metal-hydride batteries for the aerospace market and to establish a testing database to support future applications.
Coates, Dwaine, Fox, Chris, Miller, Lee
75 AH and 10 Boilerplate Nickel-Hydrogen Battery Designs and Test Results9293238/3/1992
The 75 Ah actively cooled bipolar battery continues to undergo LEO life testing at 40% DOD and to date has completed 13,000 cycles. The EOC and EOD voltages indicate that there is slight degradation in the overall battery performance. The primary influence in this decline is considered to be one cell's poor performance. The potential for extended cycle life capability of bipolar batteries has been demonstrated. Ten 4-cell passively cooled bipolar batteries are on test at Space Systems/Loral (SS/L). Characterization testing has been completed. The results indicate that high capacity utilizations can be maintained at various discharge rates. Performance differences were noted and seem to be related to battery design variations. Further testing is planned.
Daman, M. E., Manzo, M., Chang, R., Cruz, E.
Post Storage Conditioning of Nickel-Hydrogen Battery Cells9292568/3/1992
Extended room temperature storage of nickel-hydrogen battery cells has resulted in a capacity loss when the cells are initially cycled following the storage period. Because it may be necessary to “store” nickel-hydrogen batteries for long periods at room temperature (i.e., shipment, installation, etc.), tests were performed to establish the effects on capacity recovery of several post-storage conditioning methods. The tests included two groups of cells; a 60-day storage group and 120-day storage group. Each group comprised three 2-cell packs. The capacity of each cell was measured under the same controlled conditions both prior to storage and after post-storage conditioning. Each 2-cell pack in a group was conditioned differently over a 13-day period following storage. The results attained with the 60-day storage group were essentially confirmed with the 120-day storage group. In addition, Group 1 was subjected to a second 60-day storage period after which the effects of variations of the conditioning methods were evaluated. The paper describes in detail the cell design, the test procedures, and the test results.
Verrier, D. C., Donley, S. W.
Thermal Dissipation of a Nickel-Hydrogen Battery Cell9213667/1/1992
The thermal dissipation of a 48-Ah nickel-hydrogen (Ni/H2) battery cell has been derived by testing it in a controlled radiative environment. Temperature profiles and corresponding cell thermal dissipations are presented for different battery discharge/charge cycles. A comparison between test results and theoretical predictions for battery dissipation is presented. The thermal capacitance of a Ni/H2 cell is computed from both test data and tabulation of individual cell component weight and specific heat.
Kelly, W. H., Vaidyanathan, H.
Nickel Alkaline Batteries for Space Electrical Power Systems9010554/1/1990
Nickel alkaline batteries used in spacecraft electrical power subsystems are either nickel-cadium or nickel-hydrogen. The nickel-cadmium battery has been used since the beginning of the space program, while the nickel-hydrogen battery is a relative newcomer. Both couples are still used extensively, and recent advances in each have been documented. There are advantages and disadvantages in the use of either chemistry, but the nickel-hydrogen battery appears to be more attractive for longer life and higher specific energy for payloads greater than one kilowatt.
Pickett, David F.
Items per page:
1 – 11 of 11