NASA follows top level safety requirement of two-failure tolerance (t hree levels of controls or design for minimum risk) to all catastroph ic hazards in the design of safe li-ion batteries for space use. ? R  igorous development testing at appropriate levels to credible offnominal conditions and review of test data. ? Implement robust design con  trols based on test results and test again to confirm safety at the a ppropriate levels. ? Stringent testing of all (100%) flight batteries  (from button cells to large batteries)

Jeevarajan, Judith

NASA Technical Reports Server

End User Acceptance –
Requirements or 
Specifications, Certification, 
Testing
Judith Jeevarajan, Ph.D
Power Systems Branch
NASA-JSC
April 11, 2013
NTSB Li-ion Battery Forum
https://ntrs.nasa.gov/search.jsp?R=20130012733 2019-08-31T00:46:26+00:00Z
NASA Human-Rated Li-ion Battery Applications
• Current:  Flying Li-ion since 1999
• Government  furnished equipment ~ 20 types (< 20V/ 10 Ah)
• Experiments/Payloads (55 to 60 types) up to 270 V (high energy, high
power, capacity 2 to 20 Ah
• Crew suit (main power)  20 V/ 40 Ah
• Space vehicles and Space Launch Systems 
– HTV (32 V / 174 and 100 Ah), SpaceX (28 V/ 200 Ah and 28 V/16.5 Ah)
• Future (and in work):
– ISS Main Power (120 V / 134 Ah)
– Robonaut (106 V / 60 Ah)
– New Tools (18 V to 28 V / 8Ah)
– New Vehicles (Orion (120 V/ 30 Ah, Orbital, 28 V/190 Ah, Boeing, 
SNC, Blue Origin) 
– Surface mobility systems (270 V / 60 Ah high power)
– Lunar Lander Platforms (varying); Habitats (≥ 28 V)
• Uniqueness:  
– Space, confined volume and human-rated with zero 
tolerance to fire
– pressurized and unpressurized environments
2J. Jeevarajan, Ph.D.
NASA-JSC
Non Human-rated NASA Li-ion Battery Applications 
Deep Space Missions: First 
mission in 2002) ( Maj. 20 to 
70 Ah; one at 120 Ah)
Current:
• Mars Exploration Rover (Spirit and 
Opportunity)
• Mars Phoenix Lander
• Juno (Jupiter Obiter)
• Kepler
• NuStar
• GRAIL
• Aquarius
• Mars Science Laboratory
• SMAP (On-going) and
Future:
• Europa Orbiter
• Mars 2020 Rover
• Mars Insight (Lander)
Satellite Applications: First mission in 
2006 (6 Ah to 134 Ah)
Current:
• Lunar Reconnaissance Orbiter (LRO)
• Solar Dynamics Observatory (SDO)
• Van Allen Probes (formerly RBSP Radiation Belt 
Storm Probes)
• Interstellar Boundary Explorer (IBEX)
• ST-5 (mission completed)
Future:
• Global Precipitation Measurement (GPM) 
spacecraft
• Magnetospheric Multiscale (MMS) spacecrafts
• Mars Atmosphere and Volatile EvolutioN (MAVEN) 
• DSCOVR (Triana) spacecraft 
• James Webb Space Telescope (JWST)
• Joint Polar Satellite System-1 (JPSS-1)
• Solar Probe Plus
• Ice, Cloud and Land Elevation Satellite -2 
(ICESAT-2)
• GeoStationary Operational Environmental Satellite 
(GOES-R) 
3
J. Jeevarajan, Ph.D.
NASA-JSC
Current State for Safety of Li-ion Batteries
Although the chemistry is one that can provide very high energy
density for rechargeable systems (significant weight advantage for
NASA), it is not the safest due to the nature of the associated
catastrophic failures such as
• electrolyte leakage (toxicity hazard in crewed environments), 
• fire and 
• thermal runaway 
Typical causes for catastrophic failures encountered in Li-ion cells/ 
batteries are
• Overcharge/overvoltage
• External shorts
• Repeated overdischarge; overdischarge with subsequent charge 
• High thermal environments
• Internal Shorts
NASA human-rated safety requirement is two-fault tolerance to 
catastrophic failures or design for minimum risk in cases where 
designing fault tolerance is impossible 
• Two-fault tolerance – three levels of control to all credible failures
J. Jeevarajan, Ph.D.
NASA-JSC
4
Failure Modes and Controls or Mitigation Measures
for Li-ion Batteries
5
High temperatures/High 
Thermal Environments
*Thermal analysis leading 
to appropriate thermal 
sensing; Verified by test
Design qualified to extreme 
temps
*Manuf. Spec.
Repeated 
Overdischarge/ 
overdischarge
followed by charge
Min. 3 controls 
verified by test
*Manuf. Spec.
Overcharge
Min. 3 controls
Verified by test
*Manuf. spec
External Shorts
High and Low 
Impedance
Controls and Design 
for Minimum Risk
Verified by test; 
*heat dissipation 
Internal Short
Design for Minimum 
Risk
Stringent testing and 
screening of flight cells; 
manuf. Facility audits
•Impeccable cell 
quality, cell uniformity
•Backup Slide 20
Stringent Monitoring and Control of 
*Cell and battery voltage 
*Battery current
*Temperature
Cell Balancing designed into a 
majority of applications
Concerns with Scaling and Testing- Cell to Module 
to Battery level
• NASA Centers have carried out extensive testing on li-ion batteries in 
the past 15 years –for human and non-human rated missions
• NASA Centers have learned that cell level controls do not necessarily 
translate to module or battery level controls  (Backup slides 15 and 
16)
• NASA Centers have learned that all safety controls need to be 
verified by testing at the appropriate level and in the relevant 
environment
– Hazards such as overcharge and external short have opposite 
outcomes in pressurized versus non-pressurized environments 
due to the difference in heat dissipation
6
J. Jeevarajan, Ph.D.
NASA-JSC
Concerns with Scaling and Testing- Cell to Module 
to Battery level
• Li-ion battery designs should have high fidelity thermal analysis to 
show that the battery design is safe under worst case environments 
(temperatures and pressures) and under all nominal and off-nominal 
conditions.
– Results of thermal analysis should provide guidance on safe 
designs with very good heat dissipation paths.
– Good thermal design increases safety as well as extends the life 
of the battery
• Li-ion battery management electronics should be robust 
– strike a balance in monitoring and control; 
– extensive testing of control electronics should be carried out on 
ground
– For human-rated safety critical applications insight into telemetry
should be appropriate for trouble-shooting off-nominal events. 
7
NASA Standards and Certifications
"Human-Rating Requirements for Space Systems"   NPR 8705.2B 
(2009)
Evolution of requirements occurs with rigorous testing (Backup Slide 17) 
Human-rated:
Crewed Space Vehicle Battery Safety Requirements, JSC 20793
• Manned Space Vehicle Battery Safety Handbook (since 1982) converted to 
Crewed Space Vehicle Battery Safety Requirements, current is Rev B. April 
2006; working on Rev C now; in parallel AIAA battery safety document in 
preparation.
• Battery Processing, JWI 8705.3 and Battery Evaluation Forms (required for all 
batteries from button cells to large li-ion)
NASA NESC RP-08-75 “Database and Guidelines Document Developed for Lithium-
ion Battery”
Non-Human Rated:
– Have tailored requirements based on programs/projects (as a minimum, 
need to meet Range safety and Launch readiness reviews and 
AFSPCMAN 91-710); 
– safety requirements for ground processing, integration and launch are 
very similar to human-rated li-ion battery systems; 
– on-orbit safety maybe reduced to one-fault tolerance in many cases.8
J. Jeevarajan, Ph.D.
NASA-JSC
Summary
• NASA follows top level safety requirement of two-failure tolerance 
(three levels of controls or design for minimum risk) to all 
catastrophic hazards in the design of safe li-ion batteries for space 
use
• Rigorous development testing at appropriate levels to credible off-
nominal conditions and review of test data
• Implement robust design controls based on test results and test 
again to confirm safety at the appropriate levels
• Stringent testing of all (100%) flight batteries (from button cells to 
large batteries)
9
J. Jeevarajan, Ph.D.
NASA-JSC
Back Up 
10
J. Jeevarajan, Ph.D.
NASA-JSC
Li-ion Battery Project And Safety Review Life Cycle 
• Systems Requirements Review (SRR)
– Project or Product Technical Requirements Specification (PTRS)
• Outlines battery specifications, mission requirements for 
performance and safety, interfaces (mechanical, electrical, 
data, pressure, etc.) and unique requirements such as 
pressure variations, thermal extremes, vibration, shock, 
impact, water proofing, humidity, salt fog, etc.
• Preliminary Design Review (PDR) 
– Cell and Battery Design chosen at this point) (Phase 0/1 Safety Review)
• Critical Design Review (CDR)
– Confirmed cell and battery design (Phase II Safety Review)
• Manufacturing readiness review (MRR)
– Before start of cell manufacturing and/or battery manufacturing
• Flight Readiness Review (FRR)
– Includes approved safety data packages (Phase III safety review and final 
approval)
11
J. Jeevarajan, Ph.D.
NASA-JSC
Sample Flow Chart for Li-ion Battery Acceptance
12
J. Jeevarajan, Ph.D.
NASA-JSC
Sample Li-ion Battery Qualification Tests
 Physical and Electrochemical Characterization (mass, 
dimensions, OCV, capacity, dc resistance/ac impedance, 
 Charge/discharge cycles (typically with mission profile) at 
temperature extremes (+ /- 20 deg F of mission temperature 
range)
 Vibration to qualification levels (15 mins in each axis)
 Charge/discharge cycles 
 Vacuum leak Check (6 h exposure; 0.1 psi for pressurized; 10-5
Torr for those used in vacuum environments)
 Charge/discharge cycles
Pass/fail criteria is stringent with OCV (< 0.1 % change); capacity 
checks (1 to 5% depending on battery size) and mass checks 
(0.1 to 1% change depending on battery mass)
13
FREQ (Hz) ASD (G2/Hz) dB/OCT Grms
20.00 0.057600 * *
40.00 0.057600 0.00 1.07
70.00 0.144000 4.93 2.02
700.00 0.144000 0.00 9.74
2000.00 0.037440 -3.86 13.65
J. Jeevarajan, Ph.D.
NASA-JSC
Sample Li-ion Flight Battery Acceptance Tests
Cell Acceptance: As a minimum, physical and electrochemical characterization; 6 sigma 
range accepted; if more than 3% of lot fails, the entire lot is rejected
Cell Matching: As a minimum, from accepted cells, the cells are matched for modules 
(banks and strings) based on the following: OCV (0.1 % variance), capacity (less 
than 2%), dc resistance (10% variance)
Battery Flight Acceptance Testing:
– Physical and Electrochemical Characterization (mass, dimensions, OCV, capacity, dc 
resistance/ac impedance, 
– Vibration to levels higher than workmanship (1 min per axis)
– Charge/discharge cycles 
– Vacuum leak Check (6 h exposure; 0.1 psi for pressurized; 10-5 Torr for those used 
in vacuum environments); thermal vacuum exposure tests for batteries to be used in 
unpressurized volume
– Charge/discharge cycles
Pass/fail criteria is stringent with OCV (< 0.1 % change); capacity checks (1 to 5% 
depending on battery size) and mass checks (0.1 to 1% change depending on 
battery mass)
14
FREQ (Hz) ASD (G2/Hz) dB/OCT Grms
20.00 0.028800 * *
40.00 0.028800 0.00 0.76
70.00 0.072000 4.93 1.43
700.00 0.072000 0.00 6.89
2000.00 0.018720 -3.86 9.65
J. Jeevarajan, Ph.D.
NASA-JSC
Examples of Cell Protective Devices
• Lithium-ion cells, whether cylindrical, prismatic, etc. irrespective of size, have 
different forms of internal protective devices
– PTC
– CID
– Tab/lead meltdown (fusible link type)
– Bimetallic disconnects
- etc.
• External protective devices used in
lithium-ion battery designs are 
– Diodes
– PTC/polyswitch/contactors
– Thermal fuses (hard blow or resettable)
– Circuit boards with specialized wire traces
– etc.
Although cell level protective devices protect cells and low voltage /low capacity 
batteries (less than 12 V and 60 Wh), extensive testing at NASA-JSC has 
shown that cell level protective devices do not always protect when the cells 
are used in batteries of high voltage and high capacity.
CID Top disc
Insulator 
Bottom disc
Tab
Diode
15
J. Jeevarajan, Ph.D.
NASA-JSC
J. Jeevarajan, Ph.D.
NASA-JSC
Examples Showing Cell Limitations in Multicell 
Configuration
48V 6A Overcharge on 4P Battery
Photos show the limitations of 
18650 size cells; 
These cells are only test 
vehicles; protective devices, 
Internal and external to the 
cells, irrespective of cell size,
should be fully characterized at 
all appropriate 
levels if used within the first 
three levels of safety control.
12V 6A Overcharge on 4P Battery
External Short on 8S5P 
Matrix Pack
16Overcharge Test on a 14-Cell String 
Studies In the Area of Lithium-ion Technology
• Funding for surveillance task (more than 2 decades)
– Previously Shuttle
– Currently International Space Station, NASA Engineering Safety 
Committee (NESC), Office of Chief Technologist (OCT),  Seed Funds 
from NASA HQ and Center Level Discretionary funds
• Types of Test Programs
– State-of-the-art cell technology (commercial cells of increasing 
capacities, high energy and power density, pouch type, etc.) –
performance and safety characterization
– General issues faced by li-ion technology – limitations of cell internal 
protective devices, safety characteristics under different environmental 
conditions, overdischarge – cell mismatch study, matrix design 
performance and safety characterization, internal short test method 
standardization, implantable on-demand internal short circuit device
– Technology improvements – safer electrolytes, electrode improvements 
– tested in ≥ 2 Ah to confirm safety
17
J. Jeevarajan, Ph.D.
NASA-JSC
Sample Testing and Acceptance For COTS Li-ion 
Batteries
18
J. Jeevarajan, Ph.D.
NASA-JSC
Lot Testing
Sample Testing and Acceptance Process for 
NASA/Custom Designed Li-ion Batteries
19
J. Jeevarajan, Ph.D.
NASA-JSC
Test
Design
Retest
Sample of Strong Correlation between soft short test 
failures and cell defects
20
3.1
3.0
2.9
2.8
2.7
2.6
2.5
O
C
V
,
 
V
o
l
t
s
300250200150100500
Time, hours
OCV vs time for 14-day Soft Short Test
EFT1 cells (NCP25-5) worst performers
Cells with declines > 28mV in black
Decline of 2054 maybe erroneous
1970
2007
2032
1934
1949
20492008 2054
2 mm wide FOD
Measure OCV over 14 days after deep discharge within manufacturer’s specifications
J. Jeevarajan, Ph.D.
NASA-JSC


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