48V Battery System Design for Mild Hybrid Applications. Angela Duren 11 February 2016

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1 48V Battery System Design for Mild Hybrid Applications Angela Duren 11 February 2016

2 OEM Portfolio Planning; A Balanced Strategy for Fuel Economy Low voltage hybrids are a cost effective solution for higher volume impact on fuel economy requirements EV 48V Fuel Economy Requirements HEV Mild hybrid Micro-hybrid sales volume

3 Fuel Efficiency Options Weighing technology maturity and consumer acceptance Powertrain efficiencies + Most mature technologies + Typically modest gains; except engine downsizing + Usually transparent to consumer, unless performance is sacrificed Light weighting + Somewhat mature + Large impact if implemented across many components + Somewhat transparent to consumer except possibly in repair costs Electrification + Varying maturity by technology + Full range of impact depending on battery/motor size + Dramatic variance in levels of consumer transparency 48V mild hybrids are gaining maturity; should be transparent as startstop restarts are improved 3

4 Fuel Economy/ Emissions Impact Low Voltage Electrification Steps Two OEMs have tested A123 battery in 48V systems coupled with 1.xL engines, and average fuel economy improvement projected is 12% 4

5 48V Mild Hybrid Incremental Cost Attractive system cost per % fuel economy gain $2,500 $83 $/% Incremental system cost ($) $2,000 $1,500 $1,000 $500 $0 $167 $55 $87 $ Fuel Economy Improvement (%) 48V mild hybrid Full hybrid DCT 8-speed (from 6 speed) F lb reduction Start-stop 48V mild hybrids are now competitive among mainstream fuel saving solutions

6 A123 Continues to Expand in Low Voltage Low voltage hybridization is a strategic focus for A123 Systems A123 has now secured 9 low voltage customers globally, some with multiple programs This experience has enabled insights in market trends and technical requirements Start of Production TBA 12V micro hybrid 48V mild hybrid

7 48V Battery Requirements are Diverse Drivers of 48V systems vary globally and among vehicle types + Fuel economy/ emissions improvement (aggressive charge pulses) + Electric super charger support/ engine downsizing (aggressive discharge pulses) + High power features such as e-a/c and e-chassis + Combinations of the above Power requirements from OEMs globally + Peak charge power specifications have ranged from 2kW to 21kW + Peak discharge power specifications have ranged from 6kW to 18kW Various package locations considered affect battery life & dimensional requirements 7

8 Sizing a 48V Battery for Mainstream Markets Lithium-ion cells used for HEV applications have power/energy ratios that work well in 48V applications, but most are not sized properly to balance energy, thermal requirements, and cost Energy throughput requirements for 48V battery systems range from Wh + Sizing toward the maximum of Wh yields approximately 4Ah capacity at EOL Assuming 50% capacity needed for usable energy window and capacity fade over life, approximately 8Ah BOL capacity is required Each lithium-ion chemistry has different requirements that might change this size factor slightly, but this is a good starting point for a chemistry fit comparison 8

9 A123 Chemistry Solution Portfolio Considerations for 48V mild HEV battery solutions High Energy EV EV EV EV w/ w/ fast fast charge charge PHEV Transportation Battery Solutions Single Battery Micro-Hybrid 12V Single Battery (Europe/VDA) HEV HEV 48V Hybrid Dual Battery/ Aux 12V Micro-hybrid High Power NMC (13s) (20s) LTO Considerations of market solutions LFP (14s) + Cost will limit favorability of LTO in this application due to inherent series cell counts + NMC and LFP have most potential for mainstream success based on cost + Higher impedance of NMC makes active cooling a basic system requirement A123 concluded that LFP could be optimized to further reduce impedance and potentially reduce/eliminate the need for active cooling in most 48V applications 9

10 Introducing UltraPhosphate 8Ah prismatic cell Impedance Change by Attribute 100% 80% HEV Electrode High P/E Ultra Electrode Extreme P/E 60% 40% 20% 0% Cathode Anode Electrolyte Loading 14Ah Nanophosphate [HEV] 8Ah UltraPhosphate [48V] Nanophosphate UltraPhosphate UltraPhosphate improvements total 65% additional power over previous HEV design 10

11 RT 10s Charge Power [kw] Pack impedance [mω] Custom Battery Solution for 48V Mild Hybrids Solution Comparison Scaled to 8Ah RT 10s Pack Charge Power [kw] Pack impedance [mω] UltraPhosphate : very low impedance supports reduced system complexity without active cooling Typical peak charge power requirement for 48V mild HEV LTO NMC A123 UltraPhosphate COOLING LTO NMC UltraPhosphate Not required in most applications Usually required due to higher impedance of NMC Not required in most applications COST 40-50% more cells for voltage match Lowest cell count and reuse of xev electrodes Low cell count and optimal power density 11

12 Benefits of Eliminating Battery Cooling A simpler and more cost effective solution Packaging volume, weight, and noise reduction + Reduces battery pack dimensions with elimination of cooling components + No clean air-duct routing + No fan noise + No cabin pressure concerns No thermal integration for OEM Reduced vehicle system cost 12

13 48V UltraPhosphate Battery Specification C-sample, sourced for production in 2017 Specification Unit Performance Pack Configuration - 14s1p Chemistry - UltraPhosphate Capacity Ah 8 Minimum Voltage* V 24 Nominal Voltage V 46 Maximum Voltage* V 54 SOC Range % s C, BOL, 50% SOC kw 15 60s C, BOL, 50% SOC kw s 25 C, BOL, 50% SOC kw 16 60s 25 C, BOL, 50% SOC kw 9 Usable Energy 25 C Wh > 180 Mass kg 8 Communication Protocol CAN Length x width x height mm 304 x 108 x 95 13

14 48V Battery Life Projection without Active Cooling NEDC Drive Cycle Battery Temperatures in Shanghai Cycling in Shanghai hot climate 2.5h/day for 365 days/year 1.4 MWh yearly energy throughput 23% impedance growth over 10 years 14

15 UltraPhosphate also supports 12V Starter Battery Cold crank gap with lead-acid addressed Ultra Electrode Extreme P/E 8Ah UltraPhosphate HE Electrode High E/P 20Ah UltraPhosphate A123 has recently achieved parity with leadacid cold crank performance at -30 o C, erasing the performance barriers to mass market * Tested to BS EN lead-acid AGM 12V 60Ah Cold Cranking Amps (7.5V minimum for 10 seconds*) A123 Gen2 12V 60Ah A123 Gen3 12V 60Ah -18degC -30degC 15

16 Summary System costs of 48V architectures are competitive with other fuel saving technologies, especially with regard to cost per percent improvement and consumer acceptance Active battery cooling is an obstacle for mainstream solutions which can be solved with battery cells designed specifically for the 48V application A123 Systems 48V UltraPhosphate battery is a compact design which can support vehicle architectures designed for fuel economy improvement without active cooling 16

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