Samlexpower PST-1500-12 Owner's Manual - Section 7 |
24 | SAMLEX AMERICA INC.
Section 7 |
General information on Lead Acid
Batteries
- 85%StateofDischarge(15%StateofCharge)atveryhighC-ratedischarge
currentofC/3Amps.
- 100%StateofDischarge(0%StateofCharge)athighC-Ratedischarge
current of C/5 Amps.
- 100%discharged(0%Stateofcharge)atlowerC-rateDischargecurrentofC/10Amps.
ItisseenthatatDCinputvoltageof10V/20V,thebatteryiscompletelydischargedfor
C-rate discharge current of C/5 and lower.
In view of the above, it may be seen that a fi xed Low DC Input Voltage Alarm is not useful.
Temperature of the battery further complicates the situation. All the above analysis is based
onbatteryelectrolytetemperatureof80°F.Thebatterycapacityvarieswithtemperature.
Battery capacity is also a function of age and charging history. Older batteries have lower
capacity because of shedding of active materials, sulfation, corrosion, increasing number of
charge/dischargecyclesetc.Hence,theStateofDischargeofabatteryunderloadcannot
beestimatedaccurately.However,thelowDCinputvoltagealarmandshut-downfunctions
aredesignedtoprotecttheinverterfromexcessivecurrentdrawnatthelowervoltage.
7.13 USE OF EXTERNAL PROGRAMMABLE LOW VOLTAGE DISCONNECTS
Theaboveambiguitycanberemovedbyusinganexternal,programmableLowVoltage
Disconnectwheremoreexactvoltagethresholdcanbesettodisconnectthebattery
based on the actual application requirements. Please consider using the following
ProgrammableLowBatteryCut-off/“BatteryGuard”ModelsmanufacturedbySamlex
America,Inc.www.samlexamerica.com
- BG-40(40A)–Forupto400W,12Vinverteror800W,24Vinverter
- BG-60(60A)-Forupto600W,12Vinverteror1200W,24Vinverter
- BG-200(200A)-Forupto2000W,12Vinverteror4000W,24Vinverter
7.14 DEPTH OF DISCHARGE OF BATTERY AND BATTERY LIFE
The more deeply a battery is discharged on each cycle, the shorter the battery life. Using
morebatteriesthantheminimumrequiredwillresultinlongerlifeforthebatterybank.
AtypicalcyclelifechartisgivenintheTable7.6:
TABLE 7.6: TYPICAL CYCLE LIFE CHART
Depth of Discharge
% of Ah Capacity
Cycle Life of Group
27 /31
Cycle Life of Group
8D
Cycle Life of Group
GC2
10
1000
1500
3800
50
320
480
1100
80
200
300
675
100
150
225
550
NOTE: It is recommended that the depth of discharge should be limited to 50%.