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Smart SMBus Lithium ion Battery for Land Warrior
For The 65th Lithium Battery Technical/Safety
Group At Best Western Golden Sails Hotel, Long
Beach CA Anthony Deanni, Laura Cristo , Anthony
Pellegrino and George Au US Army CECOM
RDEC AMSEL-RD-C2-AP-BA Fort Monmouth, NJ
07703 732-427-4886 732-427-3444 George.Au_at_mail1.mo
nmouth.army.mil 20-21 Feb 2002
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Outline

• Land Warrior battery with Smart SMBus
• Charge and discharge profile of the battery.
• Discharge at various wattage load.
• Low and High temp discharge.
• Storage tests at 55C for 7 days.
• Charge Profile Variance
• Life cycles
• SOC
• Conclusion

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Smart SMbus Lithium ion battery
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Smart Batteries - SMBus

• Open specification
• Interfaces defined electrical protocol,
  battery
  data set and charger data.
• Accurate fuel gauge
• Enables system power management
• Increases runtime using data for end of life
  decisions.
• More efficient charging
• Additional info at www.powersmart.com
• www.smbus.org

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Display the data from Battery to Laptop
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Smart Battery Data (SBD)
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LI7 Rechargeable Batteries

• Vendor Brentronics
• Technology Li-ion (Moli 18650 cells), 4S4P
• Weight 2 pounds
• Nominal voltage 15V
• Capacity / Energy 7.0 Ah / 105 Wh
• Runtime at 18W 5.8 hours
• Estimated recharge time 3.3 hours

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Typical Charge and Discharge Profile

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Discharge at Various Rate
18W
9W
27W
36W
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Discharge at Various Temp at 18 watts
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Summary of Temperature Discharge at 18 watts
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LI7 Rechargeable Battery

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Summary of Temperature Discharge at 14.5 watts
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Storage Test at 55 C for 7 days.
7.61 Temporary loss 2.9 Permanent Loss
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Charge Current Variation with time Charge 16.8V,
Taper to 0.5A cutoff
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Comparison of LI7 Charging Profile

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Charge Profile Variance
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Charge Variation Result
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Discharge Life Cycle with 16.4V and 16.8V Charge
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Charge Life Cycle with 16.4V and 16.8V Cutoff
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LI7 Rechargeable Battery 16.8V, 4.5A Taper to 0.5A

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LI7 Rechargeable Battery

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Conclusion

• The Smart Land Warrior battery can be
  discharged at 30C and has 92.56 of room
  temperature capacity when the battery is
  discharging at 18 watts.
• When the battery was stored at 55 C for 7 days,
  the battery will have 7.61 temporary loss and
  2.9 permanent loss.
• Charge the battery to 16.8 Volts VS 16.4 volts,
  it can improve the capacity by 8.4 and shorted
  the charge time by 15-45 mins.

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Acknowledgements
Bren-tronics, Inc E-One Moli Energy, Inc Mr.
Steve Slane