August 2010 

NASA/TM-2010-216729/Volume II 

NESC-RP-08-75 

 

NASA Aerospace Flight Battery Program 

Wet Life of Nickel-Hydrogen (Ni-H2) Batteries 

David S. Jung and Leonine S. Lee 

Goddard Space Flight Center, Greenbelt, Maryland 

Michelle A. Manzo 

Glenn Research Center, Cleveland, Ohio 
NASA STI Program . . . in Profile

 Since its founding, NASA has been dedicated to 

the advancement of aeronautics and space science. 

The NASA scientific and technical information (STI) 

program plays a key part in helping NASA maintain 

this important role. 

 The NASA STI program operates under the 

auspices of the Agency Chief Information Officer. It 

collects, organizes, provides for archiving, and 

disseminates NASA’s STI. The NASA STI program 

provides access to the NASA Aeronautics and Space 

Database and its public interface, the NASA Technical 

Report Server, thus providing one of the largest 

collections of aeronautical and space science STI in 

the world. Results are published in both non-NASA 

channels and by NASA in the NASA STI Report 

Series, which includes the following report types: 

 TECHNICAL PUBLICATION. Reports of 

completed research or a major significant phase 

of research that present the results of NASA 

programs and include extensive data or 

theoretical analysis. Includes compilations of 

significant scientific and technical data and 

information deemed to be of continuing 

reference value. NASA counterpart of peerreviewed formal professional papers, but having 

less stringent limitations on manuscript length 

and extent of graphic presentations. 

 TECHNICAL MEMORANDUM. Scientific 

and technical findings that are preliminary or of 

specialized interest, e.g., quick release reports, 

working papers, and bibliographies that contain 

minimal annotation. Does not contain extensive 

analysis. 

 CONTRACTOR REPORT. Scientific and 

technical findings by NASA-sponsored 

contractors and grantees. 

 CONFERENCE PUBLICATION. Collected 

papers from scientific and technical 

conferences, symposia, seminars, or other 

meetings sponsored or co-sponsored by NASA. 

 SPECIAL PUBLICATION. Scientific, 

technical, or historical information from NASA 

programs, projects, and missions, often 

concerned with subjects having substantial 

public interest. 

 TECHNICAL TRANSLATION. Englishlanguage translations of foreign scientific and 

technical material pertinent to NASA’s mission. 

 Specialized services also include creating custom 

thesauri, building customized databases, and 

organizing and publishing research results. 

 For more information about the NASA STI 

program, see the following: 

 Access the NASA STI program home page at 

http://www.sti.nasa.gov

 E-mail your question via the Internet to 

help@sti.nasa.gov

 Fax your question to the NASA STI Help Desk 

at 443-757-5803 

 Phone the NASA STI Help Desk at 

443-757-5802 

 Write to: 

 NASA STI Help Desk 

 NASA Center for AeroSpace Information 

 7115 Standard Drive 

 Hanover, MD 21076-1320
National Aeronautics and 

Space Administration 

Langley Research Center 

Hampton, Virginia 23681-2199 

 

August 2010 

NASA/TM-2010-216729/Volume II 

NESC-RP-08-75 

 

NASA Aerospace Flight Battery Program 

Wet Life of Nickel-Hydrogen (Ni-H2) Batteries 

David S. Jung and Leonine S. Lee 

Goddard Space Flight Center, Greenbelt, Maryland 

Michelle A. Manzo 

Glenn Research Center, Cleveland, Ohio 
Available from: 

NASA Center for AeroSpace Information 

7115 Standard Drive 

Hanover, MD 21076-1320 

443-757-5802 

The use of trademarks or names of manufacturers in the report is for accurate reporting and does not 

constitute an official endorsement, either expressed or implied, of such products or manufacturers by the 

National Aeronautics and Space Administration. 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

1 of 39

NESC Request No.: 06-069-I (Part 3) 

NASA Aerospace Flight Battery Program 

Part 3:

Wet Life of Nickel-Hydrogen (Ni-H2) 

Batteries 

Volume II: Appendices 

February 18, 2010 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

2 of 39

NESC Request No.: 06-069-I (Part 3) 

Volume II: Appendices 

Table of Contents 

Appendix A. Electrical Testing and Destructive Physical Analysis of Nickel Hydrogen Cells 

with Various Storage Histories ........................................................................... 3

Appendix B. Analysis of Stored Nickel-Hydrogen Battery Cells .......................................... 16

Appendix C. Accelerated Cycle Test Report ......................................................................... 31
NASA Engineering and Safety Center

Technical Assessment Report 

Document #:

NESC-RP06-069

Version:

1.0

Title:

Aerospace Flight Battery Systems

Page #:

3 of 39

NESC Request No.: 06-069-I (Part 3)

Appendix A. Electrical Testing and Destructive Physical Analysis of Nickel 

Hydrogen Cells with Various Storage Histories 

Work was performed under Contract Number NNL07AM00T

Electrical Testing and Destructive Physical Analysis of 

Nickel-Hydrogen Cells with Various Storage Histories 

Hari Vaidynathan, Lockheed Martin/Comsat Technical 

Services

1.0. Summary 

The effect of wet life on the performance of nickel-hydrogen cells was investigated in this study 

that focused on electrical characterization and destructive physical analysis. The cells for this 

study were carefully selected. While the storage histories were not fully documented, the 

majority of the cells were in cold storage after the initial acceptance testing. The 26 cells used in

this study belonged to past programs such as Terra, ISS, US Government, Commercial and HST. 

Electrical characterization consisted of stabilizing the cells at 0°C, 10°C and 20°C and measuring 

the charge voltage profiles and discharge capacity, charge retention, and voltage rise from the 

discharged condition and reversal voltage. For the cells subjected to Destructive Physical 

Analysis (DPA) at Lockheed Martin/Comsat Technical Services, the fill tube of the cell was then 

cut open to determine the presence of gas. Then, the cell was dissected to extract the electrode

stack and examine the condition of the components including structural features, contaminants, 

and workmanship. Having finished the physical measurements the positive, negative, separator 

and electrolyte were analyzed for their properties such as positive active material composition, 

loading and coefficient of utilization, positive swelling and blistering, negative plate polarization, 

separator absorbency, electrolyte concentration, content and distribution. The highlights of the 

results were: 

1. The capacity of the cells was not impacted by long wet life as shown by: 

10 years wet life 120 Ah commercial cell 

13 years wet life 81 Ah Space Station cells

12-year-old 50 Ah Terra cells 

10 years wet life 90-9 US Govt. cells 

4 years dry plus 8 years wet life HST cells

10 years wet life 160 Ah aqua cells 

2. Seven cells having wet life > 7 years showed a second plateau. 

3. Reversal voltage and gas analysis showed that nickel precharge is maintained.
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

4 of 39

NESC Request No.: 06-069-I (Part 3) 

4. There is no obvious correlation between the number and size of blisters on the positive plates 

and the length of time the cells were stored. Coefficient of positive material utilization is 

unchanged. 

6. Cells stored under controlled conditions (discharged and at 0 ± 5o

C, for up to 13 years, 

maintain performance and nickel precharge. 

COMSAT Battery Laboratories received 26 nickel-hydrogen cells for analysis. All of the cells 

were characterized for their capacity at 0°C, 10°C and 20°C, charge retention, reversal voltage, 

pulse discharge and initial voltage rise. After electrical characterization 11 cells were chosen for 

destructive physical analysis at COMSAT and 11 cells were shipped to The Aerospace 

Corporation. 

2.0. Electrical Characterization 

All the cells were subjected to capacity determination cycles at 0°, 10° and 20°C, 72-hour charge 

retention at 10°C and reversal at 20°C and voltage rise in the discharged state. Table 1 shows the 

capacity of the cells at 10°C, low voltage capacity, charge retention, reversal voltage and the 

voltage rise after a resistor drain to 10 mV. 

 

All the cells met their rated capacity and there was no anomalous behavior. There were no clear 

trends in the electrical behavior of the 26 cells as a function of wet life. However, there were 

some program specific trends as detailed in the following paragraphs. 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

5 of 39

NESC Request No.: 06-069-I (Part 3) 

Table 1. Performance Data 

2.1. Capacity 

The capacity of the cells was not impacted by long wet life as shown by the results for the 

capacity measurements shown in Table 1 for cells with the following storage histories: 

 10 years wet life 120 Ah commercial cell 

 13 years wet life 81 Ah Space Station cells 

 12-year-old 50 Ah Terra cells 

 10 years wet life 90-9 US Govt. cells 

 4 years dry plus 8 years wet life HST cells 

 10 years wet life 160 Ah aqua cells 

Cell Type Activation to 1 V 2nd plateau resistor Charge reversal Voltage rise

Date S/N (Ah) (%) (Ah) Retention (%) voltage after 1 hr*

Terra,50 Ah Jan-1995 122(3.5") 66.9 NA 1.1 90.3 -0.28 0.095

Terra,50Ah Jan-1996 262(3.5") 64.7 NA 1.3 90.5 -0.29 0.084

ISS,81Ah Oct-1994 224(3.5") 100.5 5.5 8.0 85.9 -1.43 0.134

ISS,81Ah Apr-1995 306(3.5") 104.9 5.5 2.3 87.6 -0.78 0.121

ISS,81Ah Oct-1996 501(3.5") 109.0 2.2 1.1 84.7 -0.37 0.165

ISS,81Ah Jul-1997 972(3.5") 103.6 NA 1.4 88.8 -0.31 0.110

ISS,81Ah Dec-1998 1728(3.5") 100.6 NA 3.5 89.8 -0.33 0.091

ISS,81Ah Jan-2000 2170(3.5") 105.1 NA 1.2 88.9 -0.32 0.086

ISS,81Ah Oct-2001 2188(3.5") 101.7 NA 1.2 88.9 -0.32 0.134

ISS,81Ah Aug-2002 2517(3.5") 100.0 NA 1.0 88.5 -0.3 0.095

ISS,81Ah Jun-2004 2932(3.5") 106.0 NA 1.4 88.6 -0.31 0.084

ISS,81Ah Jun-2004 2933(3.5") 105.6 NA 1.1 88.7 -0.31 0.105

US Govt,90Ah Mar-1997 102(3.5") 103.3 NA 0.6 87.2 -0.38 0.080

US Govt,90Ah Mar-1997 165(3.5") 102.0 NA 0.7 87.3 -0.36 0.078

HST,90Ah Aug-2000 605(3.5") 94.7 9.2 3.8 82.2 -1.52 0.061

HST,90Ah Aug-2000 718(3.5") 95.1 9.1 3.5 84.6 -1.51 0.080

Comm.,120Ah Apr-1997 1038(4.5") 153.2 NA 1.5 87.9 -0.41 0.063

Comm.,120Ah May-1997 1052(4.5" 147.9 4.3 7.2 86.7 -1.53 0.060

Comm.,120Ah Aug-1997 1238(4.5") 151.2 NA 1.7 87.3 -0.42 0.089

Comm.,120Ah Aug-1999 1997(4.5") 139.9 NA 19.1 85.1 -1.23 0.072

Comm.,120Ah Feb-2000 2204(4.5") 146.1 NA 1.3 87.3 -0.36 0.108

Comm.,120Ah Feb-2004 2749(4.5") 139.8 NA 1.0 87.3 -0.33 0.091

Comm.,120Ah Aug-2006 2925(4.5") 143.4 NA 3.1 87.1 -0.32 0.130

Aqua, 160 Ah Nov-1997 5(4.5") 200.8 NA 3.1 85.5 -0.39 0.018

Aqua, 160 Ah Nov-1997 89(4.5") 200.8 NA 3.4 84.2 -0.4 0.016

Aqua, 160 Ah Nov-1997 15(4.5") 193.6 NA 1.8 87.7 -0.33 0.015

* after resistor drain to 10 mV

10 o

C CAPACITY DATA
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

6 of 39

NESC Request No.: 06-069-I (Part 3) 

All cells exhibited capacity greater than their rated capacity. Values ranged from 5% to 34% 

higher than rated capacity. There was no clear correlation between the value of the rated 

capacity and the wet life stand time. 

2.2. Second Plateau 

Nickel-hydrogen cells exhibit a low voltage plateau on discharge when the cells have been stored 

for an extended period, cycled extensively, or been subjected to uncontrolled handling (i.e., 

stored partially charged, stored at temperatures > 10°C, subjected to overcharge at temperatures 

> 10°C, or at rates higher than C/10). The cells that exhibited second plateaus capacity below 

1 V included three ISS cells, two HST, and two 120 Ah cells with longer wet life. This capacity 

accounted for up to 9 % of the total capacity measured at a C/2 rate of discharge. Cells 224 and 

306, the oldest of the cells from the ISS builds showed second plateaus that were not present in 

the ISS cells with shorter wet life as shown in Figure 1. 

Figure 1. 10°C Discharge Profiles for ISS 81 Ah Cells 

2.3. Resistor Drain Capacity 

The capacity remaining after the power discharge to 0.1 V was measured by discharging through 

a resistor to determine the presence of low rate active materials in the positive plate. The values 

are shown in Table 1. The cells with long wet life tended to have more resistive capacity 

indicating the presence of positive active material that is capable of discharging at very low rates. 

. 

 

0.5

0.75

1

1.25

1.5

0 20 40 60 80 100 120 140 160 180

CAPACITY (Ah)

VOLTAGE (V)

224

306

501

972

1728

2170

2188

2517

2932

2933
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

7 of 39

NESC Request No.: 06-069-I (Part 3) 

2.4. Charge Retention 

The cells in this study showed charge retention values ranging from 82.2% to 90.3% (see 

Figure 2). The general value for charge retention is 85% and the values yielded by most of cells 

were close to that thereby showing the absence of internal shorts in the cells. There was no clear 

correlation between wet life and charge retention values.

Figure 2. Charge Retention 72-Hour Open Circuit Stand, ISS Cells 

2.5. Reversal Voltage 

In general, the reversal voltage exhibited by cells with nickel precharge is < −0.35 V. All the 

cells showed that value with the exception of several cells with longer wet life such as ISS 3-224 

and 4-306 which showed −1.43 V and −0.78 V, HST 10-605 and 11-718 showed −1.51 V, and 

the commercial 120 Ah cell 22-1997 which showed −1.23 V. The larger negative values indicate 

the presence of a nickel precharge. It is not possible to quantitatively determine the amount of 

nickel precharge from the cell reversal voltage. A hydrogen precharge cell would have shown 

about −0.1 V or closer to 0 V. Figure 3 shows the voltage behavior during reversal for the HST 

cells and 90-9 US Government cells in which the HST cells exhibited −1.5 V for the reversal 

potential. Figure 4 shows the reversal voltages of the ISS cells. 

Stand, ISS cells

1.34

1.36

1.38

1.4

1.42

1.44

1.46

1.48

1.5

0 10 20 30 40 50 60 70 80

TIME (HRS)

Voltage (V)

224

306

501

972

1728

2170

2188

2517

2932

2933
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

8 of 39

NESC Request No.: 06-069-I (Part 3) 

Figure 3. Cell Reversal for HST and US Government 90 Ah Cells 

Figure 4. Cell Reversal for ISS Cells 

2.6. Voltage Rise 

The voltage recovery of the cells from a completely discharged condition yielded a value 

< 0.159 V that is in agreement with the value shown by nickel precharge cells. Thus, the 

behavior is unchanged with respect to wet life. Tables 1 and 2 give the voltage rise values for the 

cells. 

-1.8

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0 0.05 0.1 0.15 0.2 0.25

CAPACITY (Ah)

VOLTAGE (V)

SN 102

SN 165

SN 605

SN 718

-1.6

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0 0.05 0.1 0.15 0.2 0.25 0.3

CAPACITY (Ah)

VOLTAGE (V)

224

306

501

972

1728

2170

2188

2517

2932

2933
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

9 of 39

NESC Request No.: 06-069-I (Part 3) 

3.0. Gas Analysis 

The gases in the cell at the conclusion of the electrochemical tests were determined. The 

presence of gas was not indicated in any of the cells. Results are presented in Table 2. 

Comparing reversal voltage and gas analysis, a state of positive precharge is indicated in all the 

cells under test. 

Table 2. Voltage and Gas Analysis 

4.0. Cell Disassembly 

The cells were opened in a discharged state and anomalies were noted upon disassembly. In all 

cells, the components were in the proper sequence and the separator coverage was adequate. The 

canisters weld rings and end plates did not show any evidence of structural damage, were 

positioned properly, and contained drops of electrolyte. The anodes, cathodes and separators 

were easily detachable. Table 3 presents a summary of the visual observation of the condition of 

the components. 

Activation Gas on opening

Date S/N after 1 hr after 24 hr

Jan-1995 122 0.015 0.069 No gas

Oct-1994 224 0.029 0.077 No gas

Dec-1998 1728 0.022 0.075 no gas

Oct-2001 2188 0.027 0.083 no gas

Jun-2004 2933 0.025 0.089 no gas

Mar-1997 102 0.022 0.064 no gas

Aug-2000 605 0.022 0.031 no gas

May-1997 1052 0.017 0.122 no gas

Aug-1997 1238 0.020 0.116 no gas

Feb-2004 2749 0.022 0.159 no gas

Nov-1997 5 0.017 0.033 no gas

* after resistor drain to 2 mV

VOLTAGE RISE*
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

10 of 39

NESC Request No.: 06-069-I (Part 3) 

Table 3. DPA Findings of All Cells 

5.0. Electrolyte Analysis 

The electrolyte was washed from all components of the disassembled stacks. The components 

were weighed before and after washing. Table 4 lists the weight of the electrolyte determined 

for each component. Results are listed as the average weight of electrolyte in each component as 

well as the weight of electrolyte per weight of component. The negative and positive plates in 

the subject cells contained similar amounts of electrolyte, except for the 120 Ah cell that 

contained greater electrolyte in the Positive plate, and consequently, less electrolyte in the 

SEPARATORS

ACTIVATION DATE

S/N

small blisterslarge blisterserupted blistersrough surfacesscratched surfacesweak pliable platesbent plateholes in plate surfacewettedpinholesburnmarkscompression marksdirty tabsloose Ptdirt on positive sidePt on negative sidegreen stainingtears from blisterswettedburnmarksmelting at tabdirtydiscolored KOH

Oct-94

ISS 81 Ah 

S/N 224

Jan-95

EOS AM 

S/N 2-122

Mar-97

EPT 90-9 

S/N 3-102

May-97

EPT 

120Ah 

S/N 1052

Aug-97

EPT 

120Ah 

S/N 1238

Nov-97

EOS PM 

S/N 1-5

Dec-98

ISS 81 Ah 

S/N 1728

Aug-00

HST 90-3 

S/N 10-

605

Oct-01

ISS 81 Ah 

S/N 2188

Jun-04

ISS 81 Ah 

S/N 2933

FREQUENCY KEY not present or neglible

slight, found in less than 30% of modules

moderate, between 30 and 70%

extensive, greater than 70%

POSITIVE PLATES NEGATIVE PLATES SCREENS
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

11 of 39

NESC Request No.: 06-069-I (Part 3) 

separator. The amount of electrolyte in the separators tends to have the greatest variation over 

time, with greater amounts found in aged cells. The pre-activation storage mode may also 

influence electrolyte absorption during activation as components are stored under pressure 

(nitrogen). 

The electrolyte was titrated to two separate endpoints to calculate the potassium hydroxide and 

potassium carbonate concentrations. Table 5 lists the electrolyte concentrations. KOH 

concentrations have remained similar, ranging from 28.4 to 30.7-weight percent and carbonate 

concentrations of 2.8 to 3.4-weight percent. The volume of electrolyte per Ah of theoretical 

capacity in the positive electrode has varied greatly, and been dependant on positive plate 

loading. 

Table 4. Electrolyte Distribution 

The cc/Ah data calculation is in progress and shall be completed in due course. 

Activation Cell Size Pos.Plate Neg Plate Zircar Screen

DATE S/N (Ah) (g/g plate) (g/g plate) (g/g sep) (g/g scrn)

Oct-94 224 81 0.14 0.04 1.28 0.08

Jan-95 2-122 50 0.14 0.05 1.42 0.12

Mar-97 3-102 90 0.14 0.04 1.38 0.07

May-97 1052 120 0.18 0.04 1.08 0.14

Nov-97 1-5 160 0.15 0.06 1.74 0.31

Dec-98 1728 81 0.14 0.03 1.35 0.20

Aug-00 10-605 90 0.15 0.05 1.31 0.05

Oct-01 2188 81 0.15 0.03 1.29 0.28

Jun-04 2933 81 0.13 0.03 1.24 0.15
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

12 of 39

NESC Request No.: 06-069-I (Part 3) 

Table 5. Electrolyte Concentrations 

6.0. Separators 

The Zircar separators were evaluated for their absorbency, resistivity and physical appearance. 

Table 6 displays these results. Results show the subject Zircar separators to be slightly lighter 

and thinner than the virgin sample. Weights and thickness from the Lot 10 cells are very similar, 

while the Lot 11 separator samples have been slightly thinner. The electrolyte absorbency of the 

separators from the entire group of cells was higher than that shown by a virgin sample. The 

cells with later activation dates tended to have lower absorbency. 

Activation Cell Size KOH K2CO3

DATE S/N (Ah) Conc. (%) Conc. (%) cc/Ah

Oct-94 224 81 28.5 5.1 3.03

Jan-95 2-122 50 29.7 3.3 3.39

Mar-97 3-102 90 29.6 2.8 2.38

May-97 1052 120 27.1 4.7 2.82

Nov-97 1-5 160 28.4 3.4 3.73

Dec-98 1728 81 28.1 3.9 3.21

Aug-00 10-605 90 30.7 2.9 2.92

Oct-01 2188 81 28.0 4.0 3.18

Jun-04 2933 81 28.8 4.0 2.99
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

13 of 39

NESC Request No.: 06-069-I (Part 3) 

Table 6. Separator Absorbency 

7.0. Positive Plates 

The positive plate analysis consists of removing the active and sinter material from the substrate 

and from each other. Table 7 presents the results from the chemical analysis. Generally, the 

virgin plates tend to weigh less, be thinner yet have higher porosity, and have higher loading than 

their cell counterparts. This suggests plate swelling and possible sinter corrosion even in these 

cells with little cycling. The baseline values that were used for comparison are: Ni active 

material of 35.03%; Ni sinter of 49.68%; cobalt of 5.75% of the active material; plaque porosity 

of 78% and total active material loading of 1.68 g/cc void. The results reported are incomplete 

since the analysis is in progress. The cells were also analyzed for potassium in the positive plate, 

which made up approximately 1.5% of the plate mass. 

Act. Cell Size Absorbency

Date S/N (Ah) (g KOH/g sep)

1992 virgin 3.5" 2.0

Oct-94 224 81 2.8

Jan-95 2-122 50 2.9

Mar-97 3-102 90 2.7

May-97 1052 120 3.1

Nov-97 1-5 160 2.6

Dec-98 1728 81 2.5

Aug-00 10-605 90 2.5

Oct-01 2188 81 2.5

Jun-04 2933 81 3
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

14 of 39

NESC Request No.: 06-069-I (Part 3) 

Table 7. Positive Plate Analysis Comparison 

8.0. Precharge Analysis 

The capacity balance between the anode and cathode that is described as hydrogen precharge or 

nickel precharge was analyzed by several methods. For example, the absence of residual 

hydrogen in the cells at opening points to the presence of a nickel precharge. Only one cell from 

this study has had a positive pressure on opening. The positive plates were also discharged 

immediately after stack disassembly in flooded KOH. This test presented negligible residual 

capacity in cells to date. This capacity is considered to be the electrochemically active 

precharge. This value was lowest in the 90 Ah cells. Sample positive plates were also 

chemically analyzed with ferrous ammonium sulfate to determine the total charged nickel 

remaining in the plate. This value includes both the electrical and chemical portions of 

precharge. 

Table 8 presents the precharge values to date. The cells retained their original design of nickel 

precharge, but the 90 Ah cells appear to have a loss in precharge when compared to other cells. 

Activation Cell Ave. Cell Ave.

Date Weight Thickness Ni(OH)2 Co(OH)2 Co(OH)2 Sinter Substrate Sinter Plaque Ni Total Plate Cell

Identification (g) (mm) (%,g) (%,g) % of active (%,g) (%,g) (%) (%) (g/cc) (g/cc) (%) (%)

1995 Virgin EOS AM 13.05 0.767 33.19 2.02 5.66 48.64 13.15 80.4 75.8 1.48 1.71 121.6 NA

Lot 2 4.33 0.26 6.34 1.71

1997 Virgin HST 15.28 0.925 36.68 2.39 6.11 46.46 11.34 82.3 78.5 1.51 1.74 106.3 NA

Lot 11 5.53 0.36 7.00 1.71

Oct-94 S/N 224 0.811 34.49 1.93 5.26 45.43 12.63 82.2 78.3 1.46 1.78 131.6 120.6

ISS 81 Ah 4.68 0.26 6.17 1.71

Jan-95 S/N 2-122 13.58 0.805 34.05 2.58 7.00 56.49 12.55 77.6 73.9 1.55 1.67 148.1 132.3

EOS AM 4.65 0.35 7.72 1.71

Mar-97 S/N 3-102 15.65 0.947 39.69 2.43 5.72 50.45 10.87 80.5 77.2 1.70 1.80 113.9 119.0

RNH-90-9 6.26 0.38 7.95 1.71

Dec-98 S/N 1728 13.59 0.797 33.95 2.07 5.73 47.19 12.61 81.2 77.3 1.49 1.76 145.5 125.1

ISS 81 Ah 4.61 0.28 6.41 1.71

Aug-00 S/N 10-605 15.49 0.943 34.76 2.46 6.51 51.66 11.23 80.6 77.3 1.44 1.54 128.5 127.0

RNH-90-3 5.31 0.37 7.88 1.71

Oct-01 S/N 2188 13.44 0.809 33.89 2.20 6.17 46.24 12.75 82.0 78.1 1.43 1.73 153.4 129.9

ISS 81 Ah 4.56 0.30 6.22 1.71

Jun-04 S/N 2933 13.47 0.787 34.18 2.34 6.50 46.25 12.73 81.5 77.5 1.50 1.80 151.1 131.0

ISS 81 Ah 4.60 0.32 6.23 1.71

Nov-97 S/N 1-5 23.28 0.826 30.68 2.24 4.41 54.66 14.33 78.0 73.7 1.41 1.43 171.7 152.0

EOS PM 7.15 0.33 12.74 3.34

POROSITY LOADING UTILIZATION
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

15 of 39

NESC Request No.: 06-069-I (Part 3) 

Table 8. Positive Precharge 

9.0. Conclusions 

The study leads to the following conclusions: 

1. Cell capacity, charge retention, and voltage rise are not influenced by the wet life of cells. 

2. Second voltage plateau occurs in cells with longer wet life. 

3. There is no obvious correlation between wet life and the number and/or severity of 

blisters on the positive plates. 

4. Coefficient of positive material utilization is unchanged. 

5. All the cells studied indicated nickel precharge and the oldest cells showed a nickel 

precharge of 8.4 Ah. 

Rated Actual 20 o

C Electrical Chemical Total

Activation CELL ID Ah Ah to 1.0 V Ah Ah Ah

Oct-94 224 81 90.6 0.1 8.4 8.4

Jan-95 2-122 50 58.9 1.1 9.6 10.7

Mar-97 3-102 90 91.5 0.5 8.3 8.8

May-97 1052 120 130 progressing progressing 14.6

Nov-97 1-5 160 171.4 1.1 22.0 23.1

Dec-98 1728 81 89.7 1.9 14.6 16.6

Aug-00 10-605 90 82.4 0.2 9.7 9.9

Oct-01 2188 81 90.8 1.7 10.9 12.7

Jun-04 2933 81 94.4 1.2 15.1 16.3

CELL CAPACITY PRECHARGE CAPACITY
NASA Engineering and Safety Center

Technical Assessment Report 

Document #:

NESC-RP06-069

Version:

1.0

Title:

Aerospace Flight Battery Systems

Page #:

16 of 39

NESC Request No.: 06-069-I (Part 3)

Appendix B. Analysis of Stored Nickel-Hydrogen Battery Cells

Work performed under Contract Number NNL07AC79T
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

17 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

18 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

19 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

20 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

21 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

22 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

23 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

24 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

25 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

26 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

27 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

28 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

29 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

30 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

31 of 39

NESC Request No.: 06-069-I (Part 3) 

Appendix C. Accelerated Cycle Test Report 

Accelerated LEO studies were conducted on two, five-cell packs of cells with long wet lives. 

The packs were tested at the Naval Systems Warfare Center, Crane Division battery test facility. 

All cells had been stored discharged at 0±5°C and had minimal cycling beyond the Acceptance 

Test Procedure (ATP) cycles. Electrical characterization data were comparable to the Lockheed 

Martin/COMSAT Corporation and TAC results. The cell packs were subjected to accelerated 

testing at 60-percent depth of discharge (DOD) in a 90-minute LEO orbit that consisted of 30 

minutes of discharge and 60 minutes of charge, at 10oC with voltage/temperature (VT) charge 

control. 

The packs were designated 7604W and 7605W. A third pack, 7606W was added as a 

replacement when Pack 7604W was damaged during the life cycle test due to an equipment 

failure after ~1200 cycles. 

Pack 7604W was comprised of five Eagle-Picher 90-9 cells from US Government programs, 

activated in March 1997. The cells were built at the Eagle-Picher, Joplin location using positive 

electrode plaque from the Eagle-Picher Colorado Springs plant that was impregnated at the 

Joplin by the C-Street (Joplin Plant) process. Life cycle testing on these cells started in August 

2007. This pack failed at cycle 1198 due to a test system failure which left the test in the charge 

condition at the maximum charge rate of 65 amps. The pack was discontinued. The cells were 

returned to Eagle-Picher. 

Pack 7605W was comprised of five, 81 Ah, Eagle-Picher cells manufactured for ISS, activated 

on May 27, 1997. The initial evaluation on these cells was completed on October 26, 2007, with 

life cycle testing starting in November 2007. 

Pack 7606W comprised of five Eagle-Picher 90-9 cells from US Government programs. Four of 

the cells were activated in April of 1995 and the fifth cell was activated in March 1997. Life 

cycle testing on these cells was initiated in May of 2008. 

As of November 2009, Pack 7605W, comprised of the ISS cells, had completed ~12,000 nominal 

cycles and had started to show signs of decay after 11,500 cycles. The US Government cell pack 

(7606W) had completed ~9,000 cycles. Pack 7606W experienced low end-of-discharge-voltages 

(EODVs) and cell divergence at 7,200 cycles. The DOD was reduced from 60 % to 15 % DOD, 

a level more representative of an HST profile. 

Trend plots and full cycle plots for each of these packs follow.
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

32 of 39

NESC Request No.: 06-069-I (Part 3) 

 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

33 of 39

NESC Request No.: 06-069-I (Part 3) 

 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

34 of 39

NESC Request No.: 06-069-I (Part 3) 

Wet Life Study Update: 

Pack 7605W: 

Cell Description: 5 ISS 81 Ah cells manufactured by Eagle-Picher and activated May 27, 1997. 

Loral/SS part #E005140-02. 

Initial Evaluation: Completed 10/26/2007. 

Life Cycle: Began 11/14/2007. 

 Test Conditions: LEO Stress test – 60% DOD, Orbit Period 90 minutes (30 minutes 

discharge, 60 minutes charge), @10oC. Charge control = VT. 

Status: Completed 1750 cycle. See attached Trendplot. 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

35 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

36 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

37 of 39

NESC Request No.: 06-069-I (Part 3) 

Wet Life Study Update: 

Pack 7605W: 

Cell Description: 5 ISS 81 Ah cells manufactured by Eagle-Picher and activated May 27, 1997. 

Loral/SS part #E005140-02. 

Initial Evaluation: Completed 10/26/2007. 

Life Cycle: Began 11/14/2007. 

 Test Conditions: LEO Stress test – 60% DOD, Orbit Period 90 minutes (30 minutes 

discharge, 60 minutes charge), @10oC. Charge control = VT. 

Status: Completed 1750 cycle. See attached Trendplot. 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

38 of 39

NESC Request No.: 06-069-I (Part 3) 
NASA Engineering and Safety Center 

Technical Assessment Report 

Document #:

NESC-RP06-069 

Version: 

1.0 

Title:

Aerospace Flight Battery Systems

Page #:

39 of 39

NESC Request No.: 06-069-I (Part 3) 
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Technical Memorandum

 4. TITLE AND SUBTITLE

NASA Aerospace Flight Battery Program

Wet Life of Nickel-Hydrogen (Ni-H2) Batteries

5a. CONTRACT NUMBER

 6. AUTHOR(S)

Jung, David S.; Lee, Leonine S.; Manzo, Michelle A.

 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center

Hampton, VA 23681-2199

 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

 8. PERFORMING ORGANIZATION

 REPORT NUMBER

L-19893 NESC-RP-08-75

10. SPONSOR/MONITOR'S ACRONYM(S)

NASA

13. SUPPLEMENTARY NOTES

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Category 16-Space Transportation and Safety

Availability: NASA CASI (443) 757-5802

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email: help@sti.nasa.gov)

14. ABSTRACT

This NASA Aerospace Flight Battery Systems Working Group was chartered within the NASA Engineering and Safety Center 

(NESC). The Battery Working Group was tasked to complete tasks and to propose proactive work to address battery related, 

agency-wide issues on an annual basis. In its first year of operation, this proactive program addressed various aspects of the 

validation and verification of aerospace battery systems for NASA missions. Studies were performed, issues were discussed 

and in many cases, test programs were executed to generate recommendations and guidelines to reduce risk associated with 

various aspects of implementing battery technology in the aerospace industry. This document contains Part 3 - Volume II 

Appendices to Part 3 - Volume I.

15. SUBJECT TERMS

Aerospace; Battery Storage History; Hubble Space Telescope; Nickel Hydrogen; Wet Life

18. NUMBER

 OF 

 PAGES

44

19b. TELEPHONE NUMBER (Include area code)

(443) 757-5802

a. REPORT

U

c. THIS PAGE

U

b. ABSTRACT

U

17. LIMITATION OF 

 ABSTRACT

UU

Prescribed by ANSI Std. Z39.18

Standard Form 298 (Rev. 8-98)

3. DATES COVERED (From - To)

January 2007 - February 2010

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

5e. TASK NUMBER

5f. WORK UNIT NUMBER

869021.03.07.01.09

11. SPONSOR/MONITOR'S REPORT

 NUMBER(S)

NASA/TM-2010-216729/Volume II

16. SECURITY CLASSIFICATION OF:

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this 

collection of information, including suggestions for reducing this burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and 

Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person 

shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

01- 08 - 2010