Samlexpower PST-1000-12 Owner's manual - Section 7 |
16 | SAMLEX AMERICA INC.
Lead-acidbatteriescanbecategorizedbythetypeofapplication:
1. Automotiveservice-Starting/Lighting/Ignition(SLI,a.k.a.cranking),and
2. Deepcycleservice.
DeepCycleLeadAcidBatteriesofappropriatecapacityarerecommendedforthe
powering of inverters.
Deep cycle Lead Acid Batteries
Deepcyclebatteriesaredesignedwiththick-plateelectrodestoserveasprimarypower
sources,tohaveaconstantdischargerate,tohavethecapabilitytobedeeplydis-
chargedupto80%capacityandtorepeatedlyacceptrecharging.Theyaremarketed
foruseinrecreationvehicles(RV),boatsandelectricgolfcarts–sotheymaybereferred
toasRVbatteries,marinebatteriesorgolfcartbatteries.UseDeepCyclebatteriesfor
powering these inverters.
Rated capacity in Ampere-hour (Ah)
Batterycapacity“C”isspecifiedinAmpere-hours(Ah).AnAmpereistheunitofmeas-
urementforelectricalcurrentandisdefinedasaCoulombofchargepassingthroughan
electricalconductorinonesecond.TheCapacity“C”inAhrelatestotheabilityofthe
batterytoprovideaconstantspecifiedvalueofdischargecurrent(alsocalled“C-Rate”)
over a specified time in hours before the battery reaches a specified discharged terminal
voltage(Alsocalled“EndPointVoltage”)ataspecifiedtemperatureoftheelectrolyte.
Asabenchmark,theautomotivebatteryindustryratesbatteriesata“DischargeRate”
C/20Amperescorrespondingto20Hourdischargeperiod.Theratedcapacity“C”in
AhinthiscasewillbethenumberofAmperesofcurrentthebatterycandeliverfor20
Hoursat80ºf(26.7ºC)tillthevoltagedropsto1.75V/Cell.i.e.10.5Vfor12Vbattery,21V
for24Vbatteryand42Vfora48Vbattery.forexample,a100Ahbatterywilldeliver5A
for20Hours.
Rated capacity in Reserve capacity (Rc)
BatterycapacitymayalsobeexpressedasReserveCapacity(RC)inminutestypicallyfor
automotiveSLI(Starting,LightingandIgnition)batteries.Itisthetimeinminutesa
vehicle can be driven after the charging system fails. This is roughly equivalent to the
conditions after the alternator fails while the vehicle is being driven at night with the
headlights on. The battery alone must supply current to the headlights and the com-
puter/ignitionsystem.Theassumedbatteryloadisaconstantdischargecurrentof25A.
Reservecapacityisthetimeinminutesforwhichthebatterycandeliver25Amperesat
80ºf(26.7ºC)tillthevoltagedropsto1.75V/Celli.e.10.5Vfor12Vbattery,21Vfor24V
batteryand42Vfor48Vbattery.
Approximaterelationshipbetweenthetwounitsis:
capacity “c” in Ah = Reserve capacity in Rc minutes x 0.6
seCtIOn 7 |
General Information on Batteries for