Table of GontentsAn Introduction toMarine/RV Deep-Cycle Batteries. . 2

Deep-CycleBatteries.. 2

Sealed Lead-Acid vs. Flooded Lead-Acid . . 2

Deep-Clcle Sealed Lead-Acid Batteries . . 2

Proper Deep-Cycle Application 3

Wha t l saCyc le? . . . 3

T J p e s o f C y c l e s . . . . . . 4

Cycle [ife. 4

Determining BatteryDepth of Discharge/State of Charge . . . .5

Ratingsand Specif icat ions .. . . . . 6

Battery Charging 7

The Interstate BatteriesCyc l i ng L ineup . . . . . . . 8

What Makes a Deep-CycleBat te ryDis t inc t i ve? . . . . . . . .8

General Charger Information . l0

Trickle Charging l0

FAQs I I

Interstate's Marine/Rv StartingBatteries 17

Tpical Applications . l7

Deep-Gycle BatteriesThere are many misunderstandings regardingMarine/RV deep-cycle batteries. This booklet isdesigned to clariff terminology and misconcep-tions and to assist you, the customer, inl. making an informed decision regarding

pr0per usage,2. extending overall battery service life, and3. maintaining battery performance at

optimum levels.Deep-Cycle BatteriesThe term "deep cycle" refers, in general, to abattery that has the capability of deeplydischarging hundreds of times. Deep-cyclebatteries are either liquid electrolyte or sealedlead acid. How do they differ from otherbatteries? An automotive starting batteryis manufactured specifically to provide aquick burst of energy thousands of times inits lifetime, while only being able to deeplydischarge less than 50 cycles during its life.

. Seafed Lead.Acid VersusFlooded Lead.AcidMarine/RV deep-cycle batteries are available intwo different lead-acid types. A flooded or liquid-electrolyte battery has vent caps to allowmaintenance, and a sealed lead-acid battery iscompletely sealed or maintenance-free. Eachis available in common battery group sizes andhas similar ratings (CCA, RC, and Ah). TheSL{ battery is used where the battery or batterybank is not easily accessible. Maintenance onthe flooded battery includes checking electrolyteand adding distilled water.

DepGllcle Sealed Lead-AcidBatteries fSl,A,Interstate offers a wide selection of SealedLead-Acid (StA) batteries for Marine/Rvuse, including both Gel Cell and AbsorbedGlass Mat (AGM) types. Because they do notrequire maintenance, many consumers preferthem. And, for applications with hard-to-reachbatteries, SLA batteries are ideal.

An Intrcductionto Marine/RV

AGM and Gel batteries are completely sealedso absolutely N0 corrosion occurs. While bothAGM and Gel Wpes are lead-acid batteries,neither will expel external gasses, such ashydrogen and oxygen during recharge. Theycombine gasses internally.

Note that AGM technology has advanced inrecent years and is now available in Marine/RVdeep-cycle and automotive starting batteries.Important: Please remember, both AGM and Gelbatteries should be recharged with a chargerthat is specifically designed for SI^,A batteries.When AGM or Gel batteries are used to replaceliquid electrolyte batteries, always check withthe vehicle or battery manufacturer for infor-mation about charging requirements.Proper Deep.CycleApplicationA Marine/RV deep-cycle battery can be use forvarious applications including boats, motorhomes,sailboats, travel trailers, tent campers, etc. Anytimean application indicates a need for batteries thatcan provide repeated deep discharye, you needMarine/RV deepcycle batteries.What Is a Cycle?A cycle refers to one battery discharge andrecharge ofanydepth (See Figure l). Theamount of battery discharge (in percent) com-pared to its full capacity determines the needfor a shallow, moderate or deep cycle. This isappropriately called battery depth of discharge(DOD) and is measured in percentages.

FIGURE 1

3

For example,400/o DOD indicates that a batteryhas been discharged by 40%o of its total capacityand has a 600/o state of charge remaining.Dfpes ol CycfesThere are three primary Wpes of batterydischarge cycles: shallow, moderate and deep.These terms help us understand the type ofcycling that batteries experience. To clariff, let'stake a look at all three types. Shallow cyclesoccur when only a small percentage of the totalbattery capacity is discharged. Following that

FIGURE 2

same line of thought, moderate or deep cyclesare discharged by a higher percentage of thebattery's total capacity (See Figure 2).

Cycle LiJeHow many cycles should a Marine/RV deep-cycle battery produce inits life? Battery cycle life is difficult to calculateand is dependent on multiple variables, includingbattery maintenance, proper recharge, batterydepth of discharge, battery temperature, cyclinguse, vibration, and overall care and consideration.

One of the more important factors is the battery'sdepth of discharge (DOD) level per cycle. As theamount of DOD is increased per cycle, there isa resulting decrease in the amount of total cyclelife and available performance retention (SeeFigure 3). If, for example, a battery is dischargedconsistently to 100% DOD (considering all othervariables are consistent), the battery's total cyclelife can be reduced to much less than one-half ofa battery discharged to only 50%0.

CYCLES TO50% CAPAC|TY

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[Rical perf.ormance a! 89'F (cycles hatved per 18'F rise).Discharged to 1.75 volts/cell. End of life at 50o/o capacity.

FIGURE 3

Therefore, to optimize performance of a Marine/RVdeep-cycle battery it is recommended that theconsistent discharge level not fall below 50%.Remembel many other factors affect battery cyclelife. If the battery is operating in a high heatenvironment (consistently above 90'F), the typicalnumber of cycles could be drastically reduced.

STATE OF DEPTH OFCHARGE DISCHARGE

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VOLTAGE SPECtFtCGRAVITY

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Det e r m i n i nJ'lIrL o Depthof Discharge/State oi ChargeBattery DOD (in percent) is the opposite ofbattery state of charge. For example, if thebattery has a 70% state of charge, the depth ofdischarge is 30% since the total must be 100%(See Figure 4). The most efficient means ofdetermining the battery's state of charge/depthof discharge on removable-fi ller-cap batte riesis by using a hydrometer. On mainience-freebatteries, an accurate digitalvoltmeter is thebest method.

4

Surface GhargeSurface charge, in general terms, refers toan inflated charge level immediately after thebattery has been charged. Surface charge affectsa voltmeter test of the battery's state-of-chargelevel more than a hydrometer test. As anexample, even hours after a charge, testing thebatteryvoltage and reading 12.66-12.75 voltsmay not be a true indicator that the batteryis fully charged. To remove battery surfacecharge, apply a load to the battery for a periodof time. For example, apply 10-15 amps for twoto three minutes, then allow the battery to sitfor one minute before retesting.Ratings and SpecilicationsMarine/RV deep-cycle batteries have ratingspecifications that include cold cranking amps(CCA), marine cranking amps (MCA), reseryecapacity (RC) and ampere hours (Ah). RCand approximate Ah ratings may not be listedon the battery decal. However, they are avail-able through your local Interstate BatteriesDistributor. Unless specified, the Ah ratings arebased on a 20-hour discharge.Gold Granking Amps ICCAI CCA isthe amount of current (amps) a battery at 0'F(-17.8'C) can deliver for 30 seconds whilemaintaining at least 1.2 volts per cell (7.2 voltsfor a l2-volt battery).Marine Granking Amps (MCAIMCA is the amount of discharge current abattery tested at 32'F (0"C) can deliver for 30seconds and maintain at least 1.2 volts per cell(7.2 volts on a l2-volt battery).

ilote: Interstate Batteries uses the RCrating established by Battery CouncilInternational (BCl). Some manufacturersuse a 15 or 23-amp discharge rate ratherthan 25-amp discharge. The lower dischargelevel allows a higher number of minutes tobe displayed (on the battery label) whichdoes not reflect the true RC minutes at a25-amp discharge.

Reserve Gapacity (RCl RC is theamount of time a battery can deliver 25 ampsat 80"F (26.7"C) without falling below 1.75volts per cell (10.5 volts on a l2-volt battery).

FIGURE 5Ampere houns (Ahl tested at 80'E It isthe amount of current (in amps) that a batterycan deliver, multiplied by the amount of hours,without falling below 1.75 volts per cell (10.5volts on a l2-volt). Most Marine/RV deep-cyclebatteries are rated on a 2O-hour discharye rate.Fxample: A l00Ah battery can deliver five amps for20 hours (amps x hours = Ah).

Battery ChargingUtilizing the correct charger and followingproper charging methods is one of the primarykeys to enhancing battery service life andperformance. Always choose a chargerspecifically designed to match the chargingrequirements (voltage and cunent) of thebattery or battery pack. If the charger unit isan on-board charger unit (i.e., alternator,generator, converter), validate its compatibilityand proper operation before or immediatelyafter installation of a newbattery. Never allow a batteryto become overcharged oroverheated. If the batterybecomes "hot to the touch"on the outside casing,immediately disconnect thecharger and allow the batteryto cool down before continuing.

sAMPS lOAMPS 15AMPS 20AMPS 25AMPS

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The Interstate Batteries Gycling LineupSuperior QuaIiJy Ptoduct Advantages:

PATENTED selenium alloyhelps reduce corrosionpenetration.

Improved 3/,t-inch(non-tapered) lugsenhance conductivity.

ComputeroptimizedAdvanced Matrix RadialGridsru meet today'sheavy cycling demands.

Automated post molding processproduces consistent reliability.

"Best in Class" ventsspecifically designed tominimize maintenance.

Extrusion-fusionintercell weld helpsimprove alignment.

Negative plate pasteexpander is extremelyresistant to heat,resulting in a 16%

increase in life cycles!

PATENTED round plate cornershelp reduce internal shorts.

Microporous polyethylene envelope separatorshelp maximize electrical performance.

NazSOr additive helps thebattery accept a charge moreeffectively arid hold it longer.

What Makes Q Deep-C11cleBattery Distinctive?Several qualities separate deep-cycle batteriesfrom starting types: thicker plates, denseractive chemical plate material and a speciallyformulated grid alloy. These and other addedfeatures allow the Interstate Marine/Rvdeep-cycle batteries to withstand the severe,repeated stress deep cycling creates.

FIGURE 6

I

General Ghargerlnformation

Various Wpes of chargers may be used onMari ne/RV deep-cycle batteri es. Most chargers,both onboard and external, are parallel-typechargers that have the capacity of reducingor tapering the current (in amps) whileregulating voltage.Although almost any type of charger willrecharge a Marine/RV deep-cycle battery tosome degree, short-term performance and long-term seruice life are directly proportional toproper recharging. It is recommended that you:r Choose the correct charger that matches thetype of batteryyou intend to recharge, i.e.,liquidelectrolyte, Marine/RV, deep cycle, automotive,maintenance-free or AGM.o Match the proper battery voltage(6-, l2-, 24- or 36-volt).r Choose the correct charger size in amps.A good rule of thumb: A charger should providea maximum of 20 amps for each 100 Ah ofthe battery.o Select a charger with a capacity sufficientto fully recharge the batteries within eightto 12 hours.. For optimum results, choose a maintenance-free type charger that is timed or automaticallyshuts off when the battery reaches a full stateof charge.o Always read and follow the charger instruction

manual's safety and proceduralrecommendations. Different

manufacturers offervarious features thatmay influencecharging parameters.

Gharging Tip: Do notdelay charging your batteries after

use. Recharge a$ soon as possible after oneday's use. Allowing the battery to sit discharged forseveral days may hamper its recharge acceptanceand ultimately its performance.

Tlickle ChargingThe term trickle charger is often used todescribe a low-current, inexpensive charger.Some trickle-type chargers may lack the

sophisticated electronic integrated circuitryto properly regulate current and/or voltage.A charger that lacks accurate voltage/currentregulation should not be used for prolongedbattery charging, or damage could occur.Some chargers have manual timers to allowa battery charge to be set for a few minutesup to several hours. Always monitor abattery during charge, whether it is onan automatic or manual setting.

Frequently AskedQuestions

L How important is an Ah rating?The Ah rating is important when determiningthe type and amount of battery or batteriesrequired to meet your specific componentloads. The battery's RC rating is in directcorrelation with Ah. An approximate Ah ratingcan be attained by multiplying the battery's RCrating by 0.6. Example: 180 RC x 0.6 = 108 Ah.2. Should I completely dischargea deep-cycle battery the first fewtimes I use it? No! A Marine/RV deep-cycle battery does not require a complete dis-charge at any time in its service life. In fact, forbest results, it is recommended to shallow ormoderately discharge the first five to 20 cycles.3. Do Marine/RV deep-cyclebatteries develop a memory? No!Iead-acid batteries do not develop a memory.What does this mean to you? Iead-acid batterieshave the ability to cycle to various amounts ofDOD anytime during their seryice life withouta memory developing inside the battery.4. Which is the most detrimentalto a battery, heat or cold? Bothextremes create battery problems. Extremeheat will allow the battery to increase itsshort-term performance level. However, heatinternally accelerates corrosion and otherdeterioration factors that reduce a battery'slife. Extreme cold battery temperatures resultin an immediate reduction of battery efficiencylevel, which reduces short-term performance.For example, a fully charged battery at 80"F

1 110

(26'C) should operate with 10070 efficiency, at32'F (0"C) with 65% efficienc$ and at 0'F(-17.8"C) with 40%o efficiency.

80 Ah wlll supply the minimum requirements at 80"F.To asaure acceptable battery cycle life and performance,

divide 80 Ah by 0.50 = 160 Ah. Use a battery system rated fot160 Ah @ 20 hour dlscharge rate.

FIGURE 7

DC amp hours = [(AC wans) 1121x1.1 x (hours of use).

FIGURE 8

5, How do I select the propertype and amount of batteriesto fit my needs?. Determine your total power requirements.. Determine approximate time of use.. Multiply hours by amps.. Divide total ampere hours by 0.50 (50V0

DOD) to maximize battery cycle life.Tip: When choosing a baftery or batteries forUolling motons, knowthat a l2-volt qnstem requiresa minimum of l.l to 1.2 amps per pound of thrust. A24-volt system requires 0.85 to 0.95 amps per poundof thrust. And a 36-volt system requircs 0.5 to 0.55amps per pound of thrust.

6. When do I need additionalbatteries? When your power requirementsexceed the Ah your battery system can provide,you will need to connect additional batteries toyour system or increase the individual batterysize (capacity). If you are consistentlyreplacing the battery or batteries beforethe warranty has expired, the capacity inyour system may not be adequate to supplyyour needs.Tip: Once a year, re-evaluate your total batteryneeds and vehicle load requirements. If you haveadded any accessories over the past year or thehours of usage have increased, increase your totalbattery capacity.

7. As a battety ages, doesefficiency decrease? Normally, aproperly charged, Mari ne/RV deep-cycle batte ry'sefficiency improves slightly after the first l0 to20 cycles. As a battery ages, its maintenancerequirements change. Near the end of usefulservice life, however, the battery will start tolose efficiency, decreasing performance andincreasing maintenance.8. ls it best to slow chargea Marine/RV deep-cycle battery?Yes! As previously mentioned, a Marine/RV deep-cycle battery should be charged at a slow cunentrate. Tlpically, a l0- to 20-amp charger is normallylarge enough to recharge a battery of 100 Ah withineight to 12 hours. A charge level of one to two ampsis often acceptable, howeve4 the battery should bemonitored periodically due to the extended chargetime. It is best to choose a charger that has anautomatic shut-offcapability. This type of chargernormally monitors the battery's charge level elec-tronically, then shuts offcompletely, or maintainsthe battery's state of charge.9. Are the Interrstate floodedMarine/RV deep-cycle batteriesmai nteh?trG€-frce? Interstate Marine/RVdeep-cycle, liquid-electrolyte batteries are "lowmaintenance." This means that maintenancecan be performed, but under normal conditionsis seldom needed. Interstate also offers sealedlead-acid batteries which are maintenance-free.

APPROXIMATEBATTERYAh (@12V)

AC WATTS 30 MIN. I (1 HOUR)

131 2

10, How do I know if my charger iscorrect for the battery's chalgingneeds? Check and/or test the battery orbatteries every four to six weeks. This actionwill determine whether your onboard or externalcharger is operating in harmony with yourbattery system. For example, if your batteriesare using an excessive amount of water (addi-tional water needed every two to three weeks),the charger may be overheating and/or over-charging your batteries. If your batteries arenot meeting the performance expected, thecharger may be undercharging the batteries. Ifthe batteries are low-maintenance, test with ahydrometer. A low state of charge will hamperthe performance and service life of the battery.11. Do I need to equalize mybatteries? When the specific gravity ofindividual cells in a battery or bank of batteriesbecome unequal by more than 15 points or whenthe battery will not come up to full charge usingnormal charging methods, an equalization chargeis needed. An equalization charge is a batterycharge at a slightly higher voltage than normal.0n a l2-volt battery system, this may be 15.5 voltsto 16.2 volts.

So how do you know if your batteries need anequalization charge? It depends on the batterytype and manufacturer. With normal use,starting (or chassis) batteries do not requireany equalization throughout their service life. Insome household or deep-cycle applications, anequalization charge may be necessary. Sealedlead-acid batteries do not require an equaliza-tion charge.Gaution: Due to the higher-charge voltage requiredwhen equalizing, it is nece$sary to consult and followvehicle and battery manufacturer'sguidelines. Some vehicle manufacturers requirecomplete battery disconnection from the vehicle'selectricaUelectronic system prior to an equalizationcharge. Always monitor the batteries duringan equalization charge. If the batteries become"hot-to-the-touch" or spew acid, disconnectimmediately!

12. When do I need to add waterto my batteries? If the vehicle'scharging system is working well with thebatteries and adequate time is allowed toproperly recharge, additional water may not benecessary. It is important to remember thatall flooded, lead-acid batteries gas H2O duringcharging, s0 you should never add premixedelectrolge to your battery! Add water, prefer-ably distilled, when the electrolyte level fallsbelow 12" above the plates. Do not overfill.Do not fill the cell higher than l/8" belowthe battery's internal vent-well. Overfillingthe battery can result in increased water lossand post corrosion. Remember, as batteriesnear their end of life, they often requiremore maintenance.13. Will it damage my batteriesto sit for weeks or months?A battery sitting unused can deteriorate fasterthan a battery that is used (recharged) daily.As a battery sits, the chemicals inside thebattery react, discharging the battery. Thisprocess is called battery self-discharging.Depending on the batterytype and temperaturc,the rate of selfdischarge varies. For example, atypical liquidelecholyte Marine/RV battery keptat a constant 80'F (26.7 " C) may self-discharyeapproximately2lVo of its capacity in three to fourmonths. If the battery has any type of vehicle elec-hical discharge, like maintaining sensor voltage,the batterywill discharge morc quickly. The batterywill not be damaged if it is rechaqed propedy.Tip: If the battery is used seasonally or sporadi-cally, place a fully-automatic charger on the batteryfor a few hours each week. Please remember tomonitor batteries during recharge.

24VOLTS,500CCA, 120RCFIGURE 9

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12 VOLTSs00 ccA

120 RC

Interstate's MarinelBVStarting BatteriesThese batteries are used primarily in themarine industry for starting purposesonly. They are built "lnterstate-tough" towithstand the most rugged conditions andhave these quality features:o Four-post designo Carrying handleso Calcium/calcium chemistry. Vibration-resistant technologyo High density active chemical material

o NazSOa additiveo Negative plate paste expander

12 VOLTS, 1000 CCA, 240 RCFIGURE 10

IBS PART NO, APPTICATION ccA McA RC@25A

24VOLTS, 1000 CCA, 240 RCFIGURE 11

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12 VOLTS, 450 AhFIGURE 12

I I*Power accessories include fish finders, auto pilot,invertors, safety systems, blowers and lighting.

FIGURE 13lnterstate Batteries offers a complete line of sealed AGM,Marine/RV deep-cycle bafteries. Contact your local lnterstatedistributor for more information about various product lines.

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