UN 38.3 Shock Test Data
Collection
Rich Byczek, Intertek
Oct 2013
http://www.psessymposium.org/
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T4: Shock
• Small Cells/Batteries = 150g/6ms = consumer
battery specs
• Large Cells/ Batteries= 50g/11ms = automotive
OEM Specs
• Large Cells -> Small Batteries: Cells at 50G,
Battery at 150G
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Measurement Methods
Shipping of Representative shipments and
packaging.
• OEM selected Samples
• OEM selected Methods
• Small, Medium, Large sample shipments
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Measurement Methods
INTERTEK RECOMMENDATIONS
Pallet (LTL) and Small (UPS, FEDEX, etc)
Assume small parcels have the roughest
handling.
Measure at package, not at device (do not
assume dampening)
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Measurement Methods
Measurement Equipment
EDR-3C by IST
- 3axis internal accelerometer
- Use 2 to test both package and
battery.
- Set minimum G threshold, to collect primarily shock pulse
data (i.e. 3G, 5G)
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Measurement Methods
May require multiple runs per shipment size and type.
• Set realistic thresholds to maximize data collection
• Potential variation from shipment to shipment
• Variation based on sample and packages size and
method.
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Measurement Methods
Measurement Analysis
-
Convert recorded data to time history
Cursory review of peaks and durations
Data “reduction” based on revised threshold
Statistical calculation of Peak G and Duration
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Measurement Methods
Resultant Shock Pulse ASSUMPTIONS
• Half Sine Pulse
• Small/ Large have separate parameters
• Peak G level: based on max for each shipment size,
regardless of method
• Duration: based on average pulse width above
threshold
• Pulse Count: TBD, based on average pulses per
shipment
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Measurement Methods
NOTE on PEAK and NUMBER of PULSES:
Increasing number of pulses may be a way to reduce
test peak levels.
Typical 1-3 pulse per direction is an ACCELERATED
TEST, and therefore peak G level may not be
representative of actual accumulated stress.
Alternate is realistic G level, with representative test
duration (number of pulses seen in a typical or
multiple shipments)
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Vibration and Shock
• “Test cells and batteries shall be secured to the testing
machine by means of a rigid mount”
• Fixturing:
• Support the product
• May simulate packaging
• May simulate mounting in position
• Not well defined currently.
• Cannot assume package dampening
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Vibration and Shock
• CONSIDER WHAT IS BEING SHIPPED!
• CONSIDER HOW IT IS SHIPPED!
• CONSIDER HOW IT IS TRANSPORTED AFTER INITIAL
SHIPMENT
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THANKYOU
Rich Byczek
Intertek Global Technical Lead
Electric Vehicle & Energy Storage
248-219-1099
[email protected]
Mike Wells
Vibration Test Department Manager
734-582-2900
[email protected]
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