J. Jeevarajan, Ph.D. / NASA-JSC 1

Lithium-ion Battery Charge Methodologies Observed with Portable Electronic

Equipment

Judith Jeevarajan, Ph.D. NASA-JSC

The 2009 Space Power WorkshopApril 21-23, 2008

https://ntrs.nasa.gov/search.jsp?R=20090016343 2020-06-17T05:27:39+00:00Z

J. Jeevarajan, Ph.D. / NASA-JSC 2

Introduction• Commercial lithium-ion batteries in portable electronic equipment has

been used by NASA for space applications since 1999.• First battery that was certified for flight and flown for Shuttle use was the

Canon BP 927 (2.7 Ah) battery pack.• Since then, numerous portable equipment with li-ion batteries have been

certified and flown and remain on-orbit for crew usage.– Laptops (two generations with third one being worked on now)– Camcorder– Camera– PDA – 2 versions (second one being li-ion polymer cells)– Satelite Phone

• Due to expense and time, certified batteries are used with different equipment with the help of adapters or by working with the manufacturer of the equipment to build the appropriate battery compartment and connector.

• Certified and dedicated chargers are available on Shuttle and on the ISS for safe charging.

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Contributors• Symmetry Resources Inc.

– Tim Nelson– Brad Strangways

• Applied Power International– Walt Tracinski

• Energy Systems Test Area– Jerry Steward– Tony Parish– Randall Parish– Jacob Collins– Joe Cook– Geminesse Dorsey– Frank Davies– Paul March– James Villarreal

• Former Battery Group Members– Scott Lazaroff– Bob Bragg– Claude Wooten

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Canon Camcorder Battery(BP 927 and BP 930)

Weight: 188.14 gDimensions: 1.52”X 2.76”X 1.50”Voltage: 7.2 V

Capacity: 3.0 AhConfiguration: 2S2P (4 cells)

Chargers:Canon CA 900 or CA 910.

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Typical Characteristics of the Canon BP 930 Battery While Being Charged on a Canon CA910 Charger

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Canon BP 930 Li-ion BatteryParallel (a) and Series (b) Imbalance Configurations

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Current and Voltage Profile for the Parallel Imbalance Configuration Test

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Voltage and Current Profiles for the Series Imbalance Test

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Panasonic Lithium-ion IBM Thinkpad Battery

Weight: 366 gDimensions: 4”X 4.5”Voltage: 10.8 VCapacity: 3.0 AhConfiguration: 4P3S (12 cells)

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Typical Voltage and Current Profile During Charge of a Panasonic Lithium-ion Battery in the IBM Thinkpad

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Overcharge of the Panasonic Lithium-ion Battery

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Circuit Board in the Panasonic Lithium-ion Battery• Firmware controls charge/discharge switches based on cell bank characteristics• Capacity gauge function is performed • Cell balancing carried out with small loads (15 mA) on banks

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Voltage Profile for the Individual Cell Banks During Overcharge of the Top Cell Bank

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Parallel (a) and Series (b) Imbalance Configurations for the Panasonic Lithium-ion Battery

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Charge Profile for the Panasonic Lithium-ion Battery During an Unbalanced Parallel Configuration of the Cell

Banks

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A31P IBM Thinkpad Battery

Physical Characteristics:Weight: 318.1 ± 1.0 gHeight: 24.9 ± 0.3 mmLength: 215.6 ± 0.6 mmThickness: 40.6 ± 1.2 mm

Electrochemical Characteristics:OCV at full charge: 12.6 VNominal : 10.8 VCapacity: 4.0 Ah

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A31P IBM Thinkpad Sanyo BatteryTypical Charge in aThinkpad

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

0 100 200 300 400

Time (min)

Volta

ge (V

)/ C

urre

nt (A

)

-10

10

30

50

70

90

110

130

150

Tem

pera

ture

(deg

F)

Temp

Current

Voltage

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Overcharge Test of Panasonic Battery in A31P Thinkpad

Cutoff Voltage : 14.1 V; Repeated overcharge permanently shuts down the battery that can be reset only at the manufacturer’s facility.

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Overcharge of Individual Cell Bank in the Thinkpad A31P Panasonic Battery

Battery does not accept any charge

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Iridium Satellite Phone Battery(ISP Battery)

Cell: 3.8 V; 950 mAhMass: 39.6 g

Re: 85 mohms

Battery: 3.8 V; 1900 mAhMass: 92.7 g

Overvoltage (2) and Undervoltage MOSFETS

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Typical Charge / Discharge Characteristics of ISP Battery in the Phone

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HandSpring PDA

Battery : Single Prismatic Cell3.8 V; 1.5 Ah; Mass: 43 g (cell only: 40.8 g, rest is casing and circuit board)

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Typical Charge/Discharge Characteristic of the HSP Battery in PDA

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HP PDA Li-ion Battery

Voltage: 3.8 VCapacity: 1.24 Ah

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Typical Charge and Discharge of Li-ion Battery in HP PDA

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HP- PDA Li-ion Polymer Expansion Pack Battery

Voltage: 3.8 VCapacity: 0.92 Ah

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Nikon EN-EL4a Li-ion Battery

Voltage: 11.1 VCapacity: 2.5 AhSanyo Li-ion Cells in 3S

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Nikon EN-EL4a Li-ion Battery Charge Characteristics in Camera

-0.5

2.5

5.5

8.5

11.5

0 20 40 60 80 100 120 140 160 180 200 220Time (min)

Volta

ge (V

) & C

urre

nt (A

)

0

10

20

30

40

50

60

70

Tem

pera

ture

(deg

. C)

charge voltage current charger temp battery temp

Detail A

Detail B

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Details of Charge Profile for the Nikon Li-ion Battery

-1.0

2.0

5.0

8.0

11.0

31.8 32.0 32.2 32.4 32.6 32.8 33.0 33.2 33.4 33.6 33.8 34.0

Time (sec)

Volta

ge (V

)

-0.25

0.25

0.75

1.25

1.75

2.25

2.75

3.25

Cur

rent

(A)

BatteryInserted

Voltage

Current

10.0

11.0

12.0

13.0

145.2 145.3 145.4 145.5 145.6 145.7 145.8 145.9 146.0

Time (min)

Volta

ge (V

)

-0.2

0.2

0.6

1.0

1.4

1.8

Cur

rent

(A)

Voltage

Current

Detail A

Detail B

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Summary and Conclusions• Charging of most Commercial-off-the-shelf batteries can be carried

out with either a dedicated charger or test equipment– Some require closure of the communication loop between battery and

charger and hence cannot be charged using test equipment /power supplies• The charge current seems to typically start dropping off before the

voltage reaches 4.2 V/cell; but there is a steady increase in voltage until the end of charge voltage is reached.

• Due to individual cell /cell bank monitoring, unbalanced cell voltage conditions reduce the current used in the charging process.

• Unbalanced cell conditions also have a limit on charge once any one cell bank reaches the safe voltage limit (~ 4.3 V)

• COTS batteries should be charged only with their dedicated COTS chargers

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Acknowledgment

Several Test Services in the Past 11 years:SRIAPIEnergy Systems Test Area- NASA- Johnson Space CenterPrograms for Funding the work – Shuttle, ISS