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UN 38.3 Shock Test Data Collection

Rich Byczek, Intertek

Oct 2013

1http://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

Mike WellsVibration Test Department Manager

734-582-2900Michael.wells@intertek.com

Rich ByczekIntertek Global Technical Lead

Electric Vehicle & Energy Storage248-219-1099

rich.byczek@intertek.com