Xantrex SW Series Owner's Manual

Contents

Xantrex SW Series Owner's Manual Manual pdf 75 page image

OPERATION 2001 Xantrex Technology, Inc.5916 - 195th Street N. E.Arlington, WA 98223Telephone: 360/435-8826Fax: 360/435-2229www.traceengineering.comSW Series Inverter/ChargerPart No. 2031-5Rev. C: February 2001Page67Once the battery voltage nears the BULK VOLTS DC setting, the voltage will be held at this level while thecurrent into the battery tapers off. The time allowed for this tapering period is called the ABSORPTIONTIME period. This setting is very important for systems which use generators since it determines how longa generator will run and when the generator shuts off. Using a generator to “trickle” charge a battery is notefficient and should be avoided. Some users may want to decrease the ABSORPTION TIME to keepgenerator-running time to a minimum. This may result in the batteries not being fully charged. The higherthe BULK VOLTS DC setting and the longer the ABSORPTION TIME period, the more fully charged thebattery would be when the charger is shut off. Often, the generator is used only to “BULK CHARGE” thebattery and the solar array is allowed to trickle charge the battery to a full charge condition.The following chart provides a guideline in setting the battery charger settings for several different types ofbatteries. The battery manufacturer is the best source of information and should be consulted if yourbattery type is not shown. Since the settings also depend on the system design, other factors may apply.Table 4, Charging Setpoints For Common Battery TypesTYPICAL BULK AND FLOAT SETPOINTS FOR COMMON BATTERY TYPESBattery Type Bulk Volts Float Volts Equalizing Charge ProcessSealed GelLead Acid battery 14.1 VDC BULK 13.6 VDC FLOAT Not Recommended - Consult manufacturerA.G.M.Lead Acid battery 14.4 VDC BULK 13.4 VDC FLOAT Charge to 15.5 VDC or as per manufacturerMaintenance-Free RV/MarineLead Calcium Battery 14.4 VDC BULK 13.4 VDC FLOAT Not Recommended - Consult manufacturerDeep-Cycle, Liquid ElectrolyteLead Antimony Battery 14.6 VDC BULK 13.4 VDC FLOAT Charge to 15.5 VDC or as per manufacturerNiCad or NiFe Alkaline Battery*(using 10 cells in series) 16.0 VDC BULK 14.5 VDC FLOAT Consult manufacturerNote: Values shown are for 12 volt systems. For 24 volt systems multiply the settings shown by 2.For 48 volt systems multiply the settings shown by 4. These settings are guidelines, refer to yourbattery manufacturer for specific settings.EQUALIZING BATTERIES (UNSEALED OR VENTED BATTERIES ONLY)In many of the inverter/charger applications, batteries are subjected to less than ideal operatingconditions. This can result in significant differences in the state-of-charge level between the individualbattery cells. Furthermore, the low charge rates and extended periods at partial charge levels can result inboth stratified battery electrolyte and inactive areas of battery plate material. If the condition is allowed toremain for extended periods of time, the battery can “sulfate” and become unusable.To correct this condition, many manufacturers recommend a periodic “equalization” charge to mix up theelectrolyte, re-activate unused battery plate material, and bring up all of the individual cells to a full state ofcharge. This requires that the battery be given a controlled “overcharge” by increasing the charge voltagefor a limited period of time. The voltage and time required are both dependent upon the amount ofcorrection required. The more frequently the batteries are equalized, the lower the equalize voltage andshorter the time period.Equalizing a battery is only recommended on unsealed or vented batteries. The process will cause theelectrolyte to gas and will release hydrogen and oxygen in the process. The chance of explosion due tothe accumulation of these gasses is therefore a realistic hazard. The batteries must be provided with goodventilation with no ignition sources present. Some users have found that the battery cell caps are subjectto clogging during an equalization charge and therefore remove them during this process. Since thebatteries may rapidly bubble while being charged, it is advised that the battery be refilled only after theequalization process is finished (if the battery electrolyte level is low, add enough to cover the platesbefore charging).