Service Manual

FeaturesManagedbyProduct
Featuresmanagedbytheproductincludetooloperationsandpowerusage
control.TheBMSdoesnottellthetoolwhattodoanditdoesnotdictatehow
muchpowerisbeingused,thetooldoes.
BatteryConguration
Whenthinkingaboutbatteryconguration,the3keytermsare:voltage,amp
hours,andwatthours.Individualcylindricalcellsareconguredinparalleland
seriestoformabatterypack.
AmpHoursandVoltage
Voltageinvolts(V),isameasureofelectricalpotential.Tobuildvoltageinacell
pack,individualbatterycellsmustbeconnectedinaseries.Forexample,the
voltageofeachbatteryis3.7voltswith3batteriesintheseries.Thetotalvoltage
is3.7volts(perbattery)times3batteries,whichequals11.1V.
Amperage,inamps(A),isameasureofinstantaneouselectricalcurrent.
Batteriesareoftenratedinamphours(Ah).Forexample,2.5amphourbattery
candischarge2.5ampscontinuouslyfor1hour.Theamphourratingisthesize
(orcapacity)oftheproductsenergysource-a2.5Ahbatterywilldohalfofthe
workofa5Ahbatteryinthesamevoltagefamily.Inordertobuildcapacity,more
stringsofcellsmustbeaddedinparallel.Theamphoursofeachindividual
batteryis2.5andthereare4batteriesinparallelresultinginatotalof10Ah.
BatteryConguration:WattHours
Watthoursisthemeasurementofworkdonebythetool.Theelectricalenergy,in
watthours(Wh),isameasurementofpowerovertimethatcanbeconvertedinto
physicalwork.Bothwatthoursofthebatteryandthetool’swatthourcapacity
areimportantinformationtoknow.
DeterminingWattHours
Watthoursisdeterminedbymultiplyingamphoursbyvolts.Usinganindividual
batterycellthathas3.7voltsand2.5amphours,means3.7voltsinaseriesof3
whichresultsinatotalvoltageof11.1volts.
Thisindicates4cellsinparallel,eachcellequaling2.5amphoursresultingin10
totalamphoursforthisconguration.T odeterminewatthours,takethetotal
voltageof11.1andmultiplybythetotalamphoursof10,resulting111watthours
forthisbatterycongurationexample.
TheoryofOperation:ServiceandRepairs
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60vBatteryServiceManual
3439-480RevA