Electric Vehicle Batteries

ElectricVehicleBatteriesNorthBayChapteroftheElectricAutoAssociation:“VoltaicPile”,Zn-CuwithNaClelectrolyte,non-rechargeable,butshortshelflife1800VoltaFirstbatterywithlongshelflife,“DanielCell”,Zn-CuwithH2SO4andCuSO4electrolytes,non-rechargeable1836EnglandJohnFedineFirstelectriccarriage,4MPHwithnon-rechargeablebatteries1839ScotlandRobertAndersonFirstrechargeablebattery,“leadacid”,Pb-PbO2withH2SO4electrolyte1859FranceGastonPlanteFirstmassproducednon-spillablebattery,“drycell”,ZnC-Mn02withammoniumdisulphateelectrolyte,non-rechargeable1896CarlGassnerNi-Cdbatterywithpotassiumhydroxideelectrolyteinvented1910SwedenWalmerJungerFirstmassproducedelectricvehicle,with“Edisonnickeliron”NiOOH-Ferechargeablebatterywithpotassiumhydroxideelectrolyte1914USThomasEdisonandHenryFordModernlowcost“Eveready(nowEnergizer)Alkaline”non-rechargeablebatteryinvented,Zn-MnO2withalkalineelectrolyte1955USLewisCurryNiH2longliferechargeablebatteriesputinsatellites1970sUSNiMHbatteriesinvented1989USLiIonbatteriessold1991USLiFePO4invented1997USEVBatteryRequirementsSafeHighPowerHighCapacitySmallandLightLargeFormatLongLifeLowOverallCostEVBatteryRequirements:SafeExamplesofEVbatterysafetyissues:Overchargingexplosivehydrogenoutgassingthermalrunawayresultinginmelting,explosionorinextinguishablefireShortCircuitexternalorinternalundernormalcircumstancesorcausedbyacrashimmediateorlatentDamageliquidelectrolyteacidleakageEVBatteryRequirements:HighPowerPower=Watts=VoltsxAmpsTypicallyratedintermsof“C”–thecurrentratiobetweenmaxcurrentandcurrenttodrainbatteryin1hour;example3Cfora100Ahcellis300ABatteryvoltagechangeswithcurrentlevelanddirection,andstateofcharge1Horsepower=746WattsChargerefficiency=~90%Batterychargeanddischargeefficiency=~95%Drivesystemefficiency=~85%AC,75%DCbatteriesmotorcontrollermotorheatheatheatshaftchargerheat100%in60%-68%out32%-40%losttoheatEVBatteryRequirements:HighPowerExampleAcceleratingordrivingupasteephillMotorShaftPower=~50HPor~37,000WBatteryPower=~50,000WDC,~44,000WACBatteryCurrent~400Afor144VnominalpackwithDCdrive~170Afor288VnominalpackwithACdriveDrivingsteadystateonflatgroundMotorShaftPower=~20HPor~15,000WBatteryPower=~20,000WDC,~18,000ACBatteryCurrent~150Afor144VnominalpackwithDCdrive~70Afor288VnominalpackwithACdriveChargingDependsonbatterytype,chargerpowerandACoutletratingExample:for3,300W,160V,20ADCfor3,800W,240V,16AACEVBatteryRequirements:HighCapacityHighercapacity=higherdrivingrangebetweenchargesEnergy=WattsxHours=VoltsxAmp-HoursWatt-hourscanbesomewhatreducedwithhigherdischargecurrentduetointernalresistanceheatinglossAmp-HourscanbesignificantlyreducedwithhigherdischargecurrentseeninEVsduetoPeukertEffectAmp-HourscanbesignificantlyreducedincoldweatherwithoutheatersandinsulationExample:483.2V100Amp-HourcellswithnegligiblePeukertEffectand95%efficienciesPackcapacity=48*3.2Volts*100Amp-Hours*.95efficiency=14,592Wh340Watt–HourspermilevehicleconsumptionrateVehiclerange=14,592Wh/340Wh/mi=42milesEVBatteryRequirements:SmallandLightCarsonlyhavesomuchsafepayloadforhandlingandreliabilityCarsonlyhavesomuchspacetoputbatteries,andtheycan’tgoanywhereforsafetyreasonsSpecificPower=powertoweightratio=Watts/KilogramSpecificEnergy=energycapacitytoweightratio=Watt-Hours/KilogramPowerDensity=powertovolumeratio=Watts/literEnergyDensity=energytocapacitytovolumeratio=Watt-Hours/liter1liter=1millioncubicmillimetersExample:1modulewith3,840Wpeakpower,1,208Whactualenergy,15.8kg,260x173x225mm=10.1litersSpecificPower=3,840W/15.8kg=243W/kgSpecificEnergy=1,208Wh/15.8kg=76Wh/kgPowerDensity=3,840W/10.1l=380W/lEnergyDensity=1,208Wh/10.1l=119Wh/lEVBatteryRequirementsLargeFormatMinimizetheneedfortoomanyinterconnects;example100AhLongLifeMinimizetheneedforbatteryreplacementeffortandcostExample:2000cyclesat100%Depth-of-Dischargetoreach80%capacitychargingatC/2;5yearsto80%capacityon13.8Vfloatat73CLowOverallCostMinimizethepurchaseandreplacementcostofthebatteriesExample:$10Kpackreplacementcostevery5yearsdriven40milesperdaydownto80%DOD=1825days,73,000miles,14centspermileSource:LifeExpectancyandTemperature,~~+-LiCO2++---+-NiZn~~~~-+~NiCd-~~~+-+PbAAGM+-+~--+PbAgel~-