Samlexpower SAM-1500C-12 Owner's manual - Section 2 |
6 | SAMLEX AMERICA INC.
SAMLEX AMERICA INC. | 7
SECTION 2 |
Features, Applications &
Principle of Operation
SECTION 2 |
Features, Applications &
Principle of Operation
Fig. 2.2 Battery Charger Stages and Voltage/Current Curves
2 Stage charging
Workingofa2StageChargerisexplainedbelow.PleaserefertoFig2.2.
2 Stages of Charging are bulk and float Stages. A 2-Stage Charger is able to recharge a
batterytoaround80%capacity.ThistypeofchargerisusedinBackup/UPSapplications
wherethebatteryremainscharged,isfloatingmostofthetimesandwilldischargeat
lesserfrequencyonlyduringpoweroutages.Chargingdetailsaregivenbelow:
• Thecharger’soutputvoltagewillbe13.8Vforchargingcurrent of 15A. • Ifthebatterywasdischargedtoalevelthatdrawshighercurrent>theBulkchargeCurrent of 15A, the charger will limit the charging current to 15A, its voltage will drop and will be clamped at the actual battery voltage when charging was started (Points 1 to 2, fig 2.1). Charging will take place at constant current limit of 15A, the battery voltage will start rising and the current demand will start reducing. When the current reduces to less than 15A, the chargerwillexitcurrentlimit/BulkChargeStage(Point2,Fig2.1)andwilloutputafixed float Voltage of 13.8V thereafter (Points 2 to 3 on the Voltage Curve in fig 2.2). battery’s in- trinsic voltage will continue to rise towards 13.8V and charging current will start to taper off (Points 2 to 3 on the Current Curve in fig 2.2). When the battery voltage has reached almost 13.8V,itwouldhavechargedtoaround80%capacityandthecurrentdrawwillbereduced tofewhundredmilliamps(around0.1%ofbatteryAhcapacity)tocompensateselfdischarge (Point 3 on the Current Curve in fig 2.2). • IfthedischargedlevelatthetimeofswitchingONwassuchthatthechargingcurrentdrawn was<15A,thechargerwillnotbeundercurrentlimitandwilloutputFloatVoltageof13.8V (Points 2 to 3 on the Voltage Curve in fig 3.2). battery’s intrinsic voltage will continue to rise towards 13.8V and charging current will start to taper off (Points 2 to 3 on the Current Curve in fig 2.2). When the battery voltage has reached almost 13.8V, it would have charged to around80%capacityandthecurrentdrawwillbereducedtofewhundredmilliamps(around 0.1%ofbatteryAhcapacity)tocompensateselfdischarge(Point3ontheCurrentCurvein fig 2.2) Bulk Charge Stage Float Charge Stage Charger Current Curve Charger Voltage Curve Time Voltage Curr en t 9 10 11 12 13 14 1 1 2 2 3 3 15A 0A LEGEND 1. Charging Starts 1 to 2. Bulk Charge Stage: Constant Current = 15A 2. Exits Bulk & Enters Float 2 to 3. Foat Stage: Constant Voltage = 13.8V Current Tapers to 0.1% of Ah Capacity 13.8V 5A 10A 20A