Owner`s manual

18 | SAMLEX AMERICA INC.
NegativePostoftherstbatterystring(Battery1ofBatteryString1asinFig.4.4),
the following abnormal conditions will result:
• Theresistancesoftheconnectingcableswillnotbebalanced.
• Theindividualbatterieswillseedifferentseriesresistances.
• Alltheindividualbatterieswillbechargedatdifferentchargingcurrentandthus,will
reach fully charged state at different times.
• Thebatterywithlowerseriesresistancewilltakeshortertimetochargeascomparedto
thebatterywhichseeshigherseriesresistanceandhence,willexperienceovercharging
and its life will be reduced.
Sizing Inverter Battery Bank
Thefollowingbasicrulesareusedtodeterminethesizeofthebatterybank:
• ActivePowerinWatts(W)=
VoltageinVolts(V)xCurrentinAmperes(A)xPowerFactor ...................... Formula 1
• Foraninverterrunningfroma12Vbatterysystem,
theDCcurrentrequiredfromthe12Vbatteriesisthe
AC power delivered by the inverter to the load in Watts (W)
divided by 10 ..................................................................................................... Formula 2
• Energyrequiredfromthebattery=
DCcurrenttobedelivered(A)xtimeinHours(H) ........................................ Formula 3
• AsaRuleofThumb,Ahcapacityofthebatteriesrequired=
2xEnergyrequiredfromthebattery ............................................................. Formula 4
Anexampleofthiscalculationfora12Vinverterisgivenbelow:
Let us say that the total continuous AC Watts delivered by the 12V inverter = 1500W.
Then,usingFormula2above,theDCcurrenttobedeliveredbythe12Vbatteries=
1500W÷10=150Amperes.
Next, the energy required by the load in Ampere Hours (Ah) is determined:
Forexample,iftheloadistooperatefor3Hours,thenasperFormula3above,theenergy
tobedeliveredbythe12Vbatteries=150Amperes×3Hours=450AmpereHours(Ah).
Finally, as per Rule of Thumb at Formula 4, the Ah capacity of the batteries should be
twice the energy required by the load in Ah=450Ahx2=900Ah.
SECTION 4 | Installation