UN 38 3 Lithiumion Battery Testing Vibration and

UN 38. 3 Lithium-ion Battery Testing Vibration and Shock Testing Requirements

UN 38. 3 Lithium-ion Battery Testing Topics • • • Key points of presentation UN 38. 3 test overview UN 38. 3 vibration and shock test details Mild and full hybrid electrical vehicle battery systems Vibration and shock issues Vibration test analysis and recommended change Shock test analysis and recommended change Summary Back-up – – Transportation scenarios Calculations Vibration Isolation Aviation shock specification 2

UN 38. 3 Lithium-ion Battery Testing Requirements KEY POINTS • Lithium-ion batteries designed for hybrid electric vehicles (HEV) are large and complicated structures. • Lithium-ion HEV batteries are proven to be durable and safe for vehicle usage by extensive testing. • Applying the existing vibration and shock requirements to lithium-ion batteries designed for use in HEVs will increase the cost of HEVs and delay the adoption of HEVs in the market. • Existing vibration and shock requirements are not valid for heavier lithium-ion HEV batteries. • The existing requirements can be modified for large batteries and still assure safe transportation. 3

UN T 1 -T 8 Tests UN 38. 3 Manual Of Tests • • T 1 – Altitude Simulation T 2 – Thermal Shock T 3 – Vibration T 4 – Physical Shock • • T 5 – External Short Circuit T 6 – Impact T 7 – Overcharge T 8 – Forced Discharge • Tests were designed primarily for cell phone and laptop cells and batteries. • Tests simulate shipping environment and conditions, not the usage environment • All tests must be passed • Tests are without packaging 4

UN 38. 3 Manual Of Tests T 3 Vibration Testing Requirements • 16 batteries – 8 Fully charged » 4 fresh and 4 with 50 cycles usage – 8 Discharged » 4 fresh and 4 with 50 cycles usage • 3 hrs in each of 3 mutually perpendicular mounting positions • Logarithmic sweep from 7 Hz to 200 Hz to 7 Hz in 15 minutes – – – 7 Hz to 18 Hz at 1 gn; amplitude decreasing 18 Hz to ~50 Hz with 0. 8 mm amplitude; acceleration increasing to 8 gn ~50 Hz to 200 Hz at 8 gn; amplitude decreasing 200 Hz to ~50 Hz at 8 gn; amplitude increasing ~50 Hz to 18 Hz with 0. 8 mm amplitude: acceleration decreasing to 1 gn 18 Hz to 7 Hz at 1 gn; amplitude increasing 5

UN 38. 3 Manual Of Tests Current T 4 Shock Testing Requirements • 16 batteries – 8 Fully charged » 4 fresh and 4 with 50 cycles usage – 8 Discharged » 4 fresh and 4 with 50 cycles usage • 18 shocks: 3 in negative and positive direction of 3 mutually perpendicular mounting positions • Shock parameters – Normal batteries: Half-sine, 150 gn peak acceleration, 0. 006 seconds pulse duration – Large batteries: Half-sine, 50 gn peak acceleration, 0. 011 seconds pulse duration – Note: Large batteries have more than 500 grams ELC 6

UN 38. 3 Manual Of Tests Pass Criteria for Both Tests • • • No mass loss No leakage or venting No disassembly No rupture No fire OCV after test > 90% of OCV before test 7

HEV Lithium-Ion Batteries Mild and Full Hybrid Applications • Mild Hybrid Applications – One electric motor – Vehicle Functions » Assist during launch and acceleration » Stop/start engine when vehicle stops » Regen braking – 120 volts (32 -36 cells) – Less than 500 Wh – 14 kg battery assembly 400 x 250 x 150 mm 16 x 10 x 6 inches 8

HEV Lithium-Ion Batteries Mild and Full Hybrid Applications • Full Hybrid Applications – Multiple electric motors – Vehicle Function » Allows electric only propulsion » Stop/start engine when vehicle stops » Regen braking – 300 -320 volts (approx. 80 -88 cells) – Less than 2000 Wh – 45 -50 kg battery 1000 x 350 x 300 mm 40 x 14 x 12 inches 9

HEV Lithium-Ion Batteries Typical Usage, Vibration and Shock OEM Vehicle Requirements • Useful Life: 15 years/ 150, 000 miles • Vibration Test Requirements – – Random vibration 1. 28 grms 10 to 2000 Hz 24 hours/axis • Shock Test Requirements – Mild HEV Battery Assembly » 132 shocks/axis at 25 g’s, half-sine, 15 ms » 6 shocks/axis at 100 g’s, 11 ms – Mild and Full HEV Package » 10 shocks/axis at 50 g’s, 6 ms 10

HEV Lithium-ion Battery Transportation • Prototype or Development Stage – – – Air and vehicle modes utilized but mostly vehicle Domestic and international Multiple shipments possible for the same battery (some in the vehicle) Batteries have not passed UN 38. 3 testing Competent Authority will be used to allow shipping • Production – – – Vessel and vehicle modes normally Domestic and international 5 or less shipments of battery before vehicle installation Starts in 2010 Must pass UN 38. 3 tests or obtain special approval 11

UN 38. 3 Vibration and Shock Testing Issues and Impact • Per Delphi Analysis and Experience: – Current battery pack designs for mild and full hybrid applications are expected to fail the T 4 vibration test – They may also fail the T 3 shock test • Redesigning to pass UN vibration and shock tests would add development time, mass and cost to HEV battery systems : – That have already met requirements for 15 years of vehicle usage – That will be shipped only a limited number of times and rarely be air • Impact – HEVs will be more costly to the consumer and possibly delayed – Adoption of HEVs will be delayed along with their ecological and energy benefits 12

UN 38. 3 Vibration and Shock Testing Test Analysis • Mild hybrid lithium-ion battery packs are about 14 kg gross. – Maximum T 3 vibration force will be ~27, 000 N. – T 4 shock will be ~41, 000 N. • Full hybrid lithium-ion packs are about 48 kg gross. It is not a large battery by current definitions. – Maximum T 3 vibration force will be ~94, 000 N. – T 4 shock will be ~141, 000 N. 13

Vibration Test Analysis • HEV battery systems are assemblies of electronic controllers, sensors, air flow ducts, cabling, cell mounting fixtures, cells, trays, covers and attachment brackets. – They are not “solid” like cells and laptop batteries. – They will have several resonant frequencies under 200 Hz. – Estimated force exerted on mild HEV batteries due to damping and resonance is approximately 27, 000 N. – Full HEV battery force is approximately 94, 000 N. • With the understanding that vibration test parameters are based on air transportation of small lithium cells and batteries, these parameters do not realistically apply to larger batteries. 14

Vibration Test Analysis • UN T 3 testing of HEV batteries at these frequencies and 8 gn is unreasonable because: – Vibration of the transportation mode is reduced due to the mass of the pack. – Test requires vibration to be “faithfully” transmitted to device, yet vibration would not directly pass from the transportation mode to the battery due to the isolation provided by the skid or container and the package. – Force levels can not be transmitted by the transportation mode » Force required to vibrate a large notebook computer battery (0. 5 kg) is ~1000 N. » 27, 000 N and 94, 000 N are very substantial forces • • 2750 kg wrecking ball falling Or stopping a 550 kg wrecking ball after falling 1 second (35 kph/22 mph) in 1 meter 9500 kg wrecking ball falling Or stopping a 550 kg wrecking ball after falling 1 second in 0. 28 meters 15

Vibration Test Analysis and Recommendation • T 3 Test Recommendation For batteries > 12 kg: – Reduce force level from 8 gn to 2 gn • Basis for recommendation – Force levels are more realistic and exceed current exerted forces. » Force required to vibrate cell and notebook batteries at 8 gn~1000 N » 1000 N applied to vibrate a mild hybrid battery is ~0. 33 g. – 2 gn is equivalent to 5880 N for a 12 kg pack – 9 hours of swept-sine vibration testing at 2 gn is still a severe test for a large battery. 16

Shock Test Analysis and Recommendation • T 4 shock forces on mild HEV batteries would exceed 40, 000 N. – Full HEV battery forces would be >140, 000 N. • Again, with the understanding that these shock values are based on air transportation of small lithium cells and batteries, these parameters do not realistically apply to larger batteries. • UN T 4 testing of HEV battery packs at these forces is unreasonable because: – These force levels could not be transmitted by the transportation mode » Force required to shock cell phone and notebook batteries at 150 gn~1500 N » 1500 N applied to shock a mild HEV battery (~500 Wh, 12 Kg) is ~6. 5 gn. – There is no source for the additional 38, 000 N. – Aviation specifications (RTCA) test for Crash Shock at 20 g maximum. • Recommend limiting acceleration to 50 gn for all batteries > 12 kg – Far exceeds realistic and expected levels – 50 gn already is used in UN 38. 3 for large batteries. 17

Summary • Mild and full HEVs will have lithium-ion batteries that will have to be tested according to UN 38. 3 Manual of Tests • UN 38. 3 T 3 vibration and T 4 shock tests are unrealistic when applied to large batteries • If these tests remain as currently written, conversion of the world vehicle fleet to hybrids will be delayed • Proposed T 3 modification is to reduce g level from 8 to 2 for batteries 12 kg or heavier • Proposed T 4 modification is to reduce g level from 150 to 50 for batteries 12 kg or heavier 18

Back-up Material Follows 19

Back-up HEV Lithium-ion Battery Transportation Scenarios • Prototype or Development Stage 1. 2. 3. 4. 5. 6. 7. 8. • Battery transported from manufacturer to airport by vehicle Airport to airport Airport to distribution center by vehicle Distribution center to HEV system integrator by vehicle HEV system from system integrator to OEM engineering by vehicle HEV (car) from OEM engineering to test site by vehicle HEV (car) back from test site to OEM engineering by vehicle HEV system from OEM engineering back to integrator by vehicle Production Stage 1. 2. 3. 4. 5. Battery transported from manufacturer to marine port by vehicle Marine port to marine port Marine port to distribution center by vehicle Distribution center to HEV system integrator by vehicle HEV system from system integrator to OEM assembly plant by vehicle 20

Back-up Calculations • Resonant Vibration Force at 8 gn – Force = [mass] x [acceleration]/[ξ, the damping constant] – Damping constant is set at. 04, empirical value based on testing similar designs – Mild Hybrid Force = 14 x 8 x 9. 8/(. 04) N or ~27, 000 N. – Full Hybrid Force = 48 x 8 x 9. 8/(. 04) N or ~94, 000 N. • Shock Force at 150 gn – – Force = [mass] x [acceleration] x Dynamic Amplification Factor is set at 2 Mild Hybrid Force = 14 x 150 x 9. 8 x 2 N or ~41, 000 N. Full Hybrid Force = 48 x 150 x 9. 8 x 2 N or ~141, 000 N. 21

Back-up Vibration Isolation 22

Back-up Calculations • Stopping a wrecking ball examples: – – – 550 kg wrecking ball after falling 1 sec in 1 meter Forceavg x distance = mass x velocity 2/2 Forceavg = (mass x velocity 2 ) / (2 x distance) Forceavg = 550 kg x (9. 8 m/s)2 / (2 x 1 m) Forceavg = 26411 kgm/s 2 Forceavg = 26411 N – – – 550 kg wrecking ball after falling 1 sec in 0. 28 meters Forceavg x distance = mass x velocity 2/2 Forceavg = (mass x velocity 2 ) / (2 x distance) Forceavg = 550 kg x (9. 8 m/s)2 / (2 x 0. 28 m) Forceavg = 94325 kgm/s 2 Forceavg = 94325 N 23

Back-up Calculations • Vibration force required for a large notebook computer – Force = [mass] x [acceleration]/[ξ, the damping constant] – Damping constant is set at. 04 – Force =. 5 x 8 x 9. 8/(0. 04) ~ 1000 N. • Acceleration resulting from 1000 N vibration force on a 12 kg battery – – Force = [mass] x [acceleration]/[ξ, the damping constant] Acceleration = Force x [ξ, the damping constant]/[mass] Acceleration = 1000 N x [. 04]/12 kg Acceleration = 3. 33 m/sec 2 or ~. 33 gn • 2 gn force applied to a 12 kg pack – Force = [mass] x [acceleration]/[ξ, the damping constant] – Force = 12 x 9. 8/(. 04) – Force = 5880 N 24

Back-up Calculations • Force required to shock 0. 5 kg notebook batteries at 150 gn – Force = [mass] x [acceleration] x Dynamic Amplification Factor – Force = 0. 5 x 150 x 9. 8 x 2 N – Force ~ 1500 N • Acceleration resulting from 1500 N shock force on a 12 kg battery – – Force = [mass] x [acceleration] x Dynamic Amplification Factor Acceleration = Force / [mass] / Dynamic Amplification Factor Acceleration = 1500 N / 12 kg / 2 Acceleration = 62. 5 m/sec 2 or ~6. 5 gn 25

Back-up Aviation Equipment Shock Requirements • “RTCA, Inc. is a private, not-for-profit corporation that develops consensus-based recommendations regarding communications, navigation, surveillance, and air traffic management (CNS/ATM) system issues. RTCA functions as a Federal Advisory Committee. Its recommendations are used by the Federal Aviation Administration (FAA) as the basis for policy, program, and regulatory decisions and by the private sector as the basis for development, investment and other business decisions. ” • Source: rtca. org 26

Back-up RTCA Specification • DO-160 D: Environmental Conditions and Test Procedures for Airborne Equipment • Shock – – – “Saw Tooth” configuration pulses 11 ms pulse for standard testing or 20 ms for low frequency testing 18 shocks, 3 per orientation 6 g Equipment operating • Crash Safety – Same as above except 1 shock/orientation at 20 g 27