OKAYA has served the battery industry for over a decade and now provides a full range of batteries to meet the different needs of every consumer. OPL uses the most superior technology and each brand offers unique features to provide maximum choice to the consumer. We provide long warranty, customer friendly and prompt after sale services in tune with our commitment to quality.

The capacity of a battery to store charge is often expressed in Ampere hour (1 Ah = 3600 coulombs). If a battery can provide one ampere (1 A) of current (flow) for one hour it has a real world capacity of 1 Ah. If it can provide 1 A for 100 hours, its capacity is 100 Ah. Battery manufacturers use a standard method to determine how to rate their batteries.

The battery is discharged at a constant rate of current over a fixed period of time, such as 10 hours or 20 hours, down to a set terminal voltage per cell. So a 100 ampere-hour battery is rated to provide 5 A for 20 hours at room temperature. The efficiency of a battery is different at different discharge rates.

Warranty duration varies with brand and type of battery. Find a list of warranty durations on all OPL batteries here. Irrespective of warranty period, OPL batteries are made to serve for many years with our guiding promise “OKAYA ka vaada, life double se bhi zyaada!”

Pro-rata warranty is a kind of partial warranty that is used for non-repairable products like tires and batteries. Under Pro-rata warranty, if a product fails before the end of the warranty cycle, the manufacturer replaces it at a cost that depends on the age of the item at the time of complaint. In this type of warranty only a part of the initial cost is covered. However, the replaced product is then covered by an equal new warranty.

If your battery fails in the pro-rata warranty cycle then depending on the value of the battery, you will get discount on the current price of the newly replaced battery. The pro-rata warranty is counted from the date of purchase to the date of complain.

For example, if a battery has 12+12 (free of cost + pro-rata) months of warranty and it fails in the 18th month, then 75% (as 75% of its duty cycle is over) value of the battery will be deducted from its current price at that point of time and you will get 25% discount on the MRP of the newly replaced battery.

An OPL battery can remain in storage for a period of 3 months after which it requires a freshening charge which will bring up the battery to its optimum performance level.

OPL inverter batteries come with a water level indicator installed by the service engineer at the time of installation of your battery. When the indicator moves down towards the red marking we have to add DM water (Demineralized water) until the indicator moves up to the green marking on the indicator. Be careful and don't add any excess water.

Lead acid batteries are 100% recyclable. Lead is the most recycled metal in the world today. The plastic containers and covers of old batteries are neutralized, reground and used in the manufacture of new battery cases. The electrolyte can be processed for recycled waste water uses. In some cases, the electrolyte is cleaned and reprocessed and sold as battery grade electrolyte. In other instances, the sulfate content is removed as Ammonia Sulfate and used in fertilizers. The separators are often used as a fuel source for the recycling process.

Yes, you may use a substitute as long as the voltage and dimensions are same. The capacity rating (shown in "Ah") may be slightly higher or lower than the original. This is fine and should not affect the unit. There are hundreds of battery manufacturers and many batteries are interchangeable. If you are in doubt, contact your nearby service station.

It may have been under charged or over charged. Check your charging device periodically to ensure it is working properly. Also, follow the do's and don'ts mentioned in the maintenance booklet supplied with your battery. If you are in doubt contact your nearby service station.

A float application requires the battery to be on constant charge with an occasional discharge. Cycle applications charge and discharge the battery on a regular basis.

A deep cycle battery is designed with the ability of being discharged and charged hundreds of times. Many of these batteries may be totally discharged before they are ever recharged.

During storage batteries gradually lose charge due to unavoidable internal chemical reaction, this is called self-discharge. If the capacity loss due to self-discharge is not compensated by recharging the battery, the capacity may become irrecoverable. Temperature also plays an important role in determining the shelf life of a battery. Batteries are best stored at 25°C. When batteries are stored in areas where the ambient temperature varies, self-discharge can be greatly increased. Check the batteries every month and charge if necessary, as instructed in the maintenance manual.

Connecting your batteries in series will generate a higher voltage. The total voltage is the sum of all individual voltages. Connecting the batteries in parallel will increase the capacity or amp hours. When you connect your batteries in a "string" (either in parallel or series) and find a battery that is not charging properly, we suggest that the entire string to be replaced.

"A 12-volt lead acid battery is made up of six cells, each cell producing approximately above 2.1 volts that are connected in series from POSITIVE (+) terminal of the first cell to the NEGATIVE (-) terminal of the second cell and so on. Each cell is made up of an element containing positive plates that are all connected together and negative plates which are also connected together. They are individually separated with thin sheets of electrically insulating, porous material "envelopes" or "separators" that are used as spacers between the positive (usually dark chocolate) and negative (usually slate gray) plates to keep them from electrically shorting to each other. The plates within a cell, alternate with a positive plate, a negative plate and so on.

A battery is created by alternating two different metals such as Lead Dioxide (PbO2), the positive plates, and Sponge lead (Pb), the negative plates. Then the plates are immersed in diluted sulfuric acid (H2SO4), the electrolyte. The types of metals and the electrolyte used will determine the output of a cell. A typical fully charged lead acid battery produces approximately above 2.1 volts per cell. The action of the lead acid storage battery is determined by chemicals used, state-of-charge, temperature, porosity, diffusion, and load.

When the active material in the plates can no longer sustain a discharge current, a battery "dies / ages". Normally a battery dies as the active positive plate material sheds (or flakes off) due to the normal expansion and contraction that occurs during the discharge and charge cycles. This causes a loss of plate capacity and brown sediment called sludge or "mud," that builds up in the bottom of the case can short the plates of a cell out. This will kill the battery as soon as the short occurs. In hot climates additional causes of failure are positive grid growth, positive grid metal corrosion, negative grid shrinkage, buckling of plates or loss of water. Deep discharge, heat, vibration, fast charging and over charging all accelerate the "aging" process. Approximately 50% of premature battery failures are caused by the loss of water due to the lack of maintenance, evaporation from high under hood heat or over charging. Positive grid growth and undercharging causing sulfation also cause premature failures."

Performing preventive maintenance on batteries is easy and should occur at least once a month during hot weather and every three months in cold weather.

Here are some simple steps to maintain your battery:

• Check the electrolyte level for non-sealed flooded batteries (with filler caps). The electrolyte level should be kept always above the minimum electrolyte level indicated by the level indicator. This can be done by adding only battery grade (de-mineralized) water, conforms to IS 1069.
• If the battery is not fully charged (100% State-of-Charge), recharge it with an external battery charger in a well ventilated area. This is because state-of-charge is based on the frequency of power cut in certain areas. Some terrains have been known to consistently undercharge the battery causing an accumulation of lead sulfate, known as sulfation. A gradual build up of sulfation will reduce the capacity as well as the life of the battery.
• Do not use tap water or water from residential Reverse Osmosis (RO) systems to refill batteries because it could contain chlorine, calcium or magnesium and produce chlorine gas or calcium or magnesium sulfate crystals. These crystals can gradually fill the pores or coat the plates which will reduce the battery's capacity and cause premature failure.
• Remove any corrosion, lead oxidation, paint or rust with a brass wire battery brush or with a "Scotch Brite" pad from the terminal's mating surfaces on both ends of each battery cables, battery posts, lugs or terminals. A stiff steel wire brush or sandpaper may damage protective lead plating on copper connectors or terminals. Corrosion is normally a white powdery substance, but could have other colors mixed in with it like gray, yellow or green. Heavy corrosion can be neutralized with a mixture of 120 gm of baking soda (bicarbonate of soda) to 1.0 Liter of warm water. Bare metal to metal mating surfaces are required for very low electrical resistance and good current conductivity.

Corrosion is caused by one or more the following:

• Dirty or wet battery tops normally caused from expansion of electrolyte from overfilled cells or weeping from faulty battery terminal seals.
• Acid fumes leaking through the vent caps which could be a sign of over charging.
• Not enough battery box or room ventilation.
• Electrolysis due to the mismatch of metal alloys used in the battery posts, lugs, terminal clamps or terminals.
• Tighten loose hold down clamps to prevent excessive vibration, battery lugs, terminals and connectors.
• Clean the battery top to eliminate conductive paths created by dried or wet electrolyte and to prevent corrosion.
• Replace any battery cables (or cable terminals) that are corroding, swelling or damaged with equal or larger diameter cable. Larger cable and lugs, connectors or terminals are better because there is more surface area and less voltage drop."

In a well ventilated area, fully charge and test the new battery. If the battery is dry charged (shipped without electrolyte), add the electrolyte but do not overfill, let it stand for approximately one hour and then slowly charge the battery at the specified level mentioned in the maintenance manual.

• If a non-sealed wet battery, check the electrolyte levels before installation and "top up" to the proper level with demineralized water as required but do not over fill. The plates need to be covered with electrolyte at all times to prevent an internal battery explosion or sulfation.
• Carefully lift the old battery out and dispose of it by exchanging it when you buy your new replacement battery or by taking it to a recycling center. Please remember that batteries contain large amounts of harmful lead, acid and other chemicals so take great care with safety and please dispose of your old battery properly to protect our fragile environment.
• After removing the old battery, insure that the battery tray or box and cable lugs are clean. Battery stores sell an inexpensive brass wire brush that will clean the inside of post lug clamps and the post terminals. If the terminals, cables or hold-down brackets are corroded, replace them. Replace any battery cables that are corroding, swelling or other damage with equal or larger diameter cable. Larger cable is better because there is less voltage drop.
• Check the positive and negative terminal markings on the replacement battery and position it so that the NEGATIVE (-) cable will connect to the NEGATIVE (-) terminal. Reversing the polarity of the electrical system can severely damage or DESTROY it. It can even cause the battery to explode.
• Connect the cables in reverse order, i.e. attach the POSITIVE (+) cable first and the NEGATIVE (-) cable last. For terminals check the length of the bolt and do not tighten more than 8.5 N-m, or you could crack the battery case. Connections need to be periodically checked for corrosion (or oxidation) and re-tightened.
• To prevent corrosion, coat the terminals and exposed metal parts with high temperature grease or white petroleum jelly."

• An equalizing charge is a special charge given to a battery when non-uniformity in voltage has developed between cells. It is given to restore all cells to a fully charged condition. Use a charging voltage higher than the normal float voltage i.e., 2.45 VPC for a maximum period of 24 hours.
• Non-uniformity of battery voltages may result from low/high float voltage due to improper adjustment of the charger or error in panel voltmeter reading. Ensure accurate setting and monitoring of float voltage.

It is required to equalize batteries when one or more of the following occur:

• Where the temperature compensated specific gravity reading difference between cells is 0.030 (or 30 "points") or greater.
• When one cell requires more water than all the other cells.
• When one cell does not require as much water as all of the other cells.

Additional words of caution and charging tips:

• Help prevent blindness and always wear safety glasses when working around deep cycle battery in the unlikely event that it might explode.
• Use the battery manufacturer's charging recommendations and temperature compensated voltages whenever possible for optimum capacity, maintenance and service life.
• Match the charger (or charger's setting) for the battery type you are recharging (or maintaining) and insure the charging voltages are compatible.
• Lead-acid batteries should always be recharged within 24 hours after they have been used and sooner the better. Before recharging, check the electrolyte and insure that it is not frozen (cold climate) and that it covers the plates at all times to prevent sulfation and to reduce the possibility of an internal explosion. Do not recharge frozen batteries because you will damage them. Allow them to thaw out first.
• After recharging, recheck the electrolyte levels after the battery has cooled, top up with de-mineralized water as required, but do not overfill.
• Reinstall the vent caps on wet (flooded) batteries before recharging and recharge ONLY in well-ventilated areas because explosive and toxic gasses can be produced during the absorption stage. Insure the vent caps are not clogged. Do not expose lead-acid batteries to a lit cigarette, sparks or flames because they produce flammable gasses and could explode.
• Follow the charger manufacturers' procedures for connecting and disconnecting cables. Connect the positive (+) lead of the charger to the positive (+) terminal post of the battery to be charged and the negative (-) lead of the charger to the negative (-) terminal post. Operate in a manner to minimize the possibility of an explosion or incorrectly charging the battery. You should always turn the charger OFF or unplug it before connecting or disconnecting cables to a battery. Do not wiggle the cable clamps while the battery is recharging, because a spark might cause an explosion. Good ventilation or a fan is recommended to disperse the gas created by the recharging process for wet batteries. As a safety feature, some chargers are designed not operate unless the battery has a partial charge or if the leads are reversed.
• If a wet battery becomes hot, over 125° F (51.5° C), or if it violently gasses or spews electrolyte, turn the charger off temporarily or reduce the charging rate. This will also prevent "thermal runaway" that can occur with AGM (Ca/Ca) VRLA batteries if the battery temperature is over 100°F (37.8° C).
• Insure that charging the battery with an external charger will not damage the electrical system or appliances with high voltages. If this is even a remote possibility, then disconnect the grounded battery cable from the battery before connecting the charger to the battery.
• If a battery is charged with a manual or defective charger and all the electrolyte is "boiled" out, some batteries can cause a FIRE or produce DEADLY CO (Carbon Monoxide) or other gasses.
• Routinely tighten cables connections.
• Do not recharge batteries with cracked or leaking battery cases.
• Continuous float charging or periodic recharging will prevent batteries from freezing. An electrolyte freeze points at various states-of-charge for a wet lead acid battery table indicates the temperature when the electrolyte will freeze."

The most important consideration in increasing the overall service life of a lead-acid battery is preventive maintenance. Protecting your battery from high temperatures with a heat shield or case, keeping it full charged at all times, and maintaining it are the easiest ways to extend it's life. In hot climates and during summer, the electrolyte levels need to be checked more frequently. For every increase of 18° F (10° C) above 77° F (25° C), positive grid corrosion or self-discharge rate is doubled. Periodically check the State-of-Charge of batteries. Based on charging systems sometimes it will undercharge the battery causing an accumulation of lead sulfate known as sulfation. This sulfation reduces the capacity of the battery. If the battery is not fully charged, recharge it periodically with an external battery charger matched to the battery type. Reducing the average DoD (Depth-of-Discharge) and the number of discharge/charge cycles, by proper deep cycle battery or battery bank sizing will significantly increase a deep cycle battery service life. If required, give periodic equalizing charge. Equalizing can also prevent electrolyte stratification, which can cause sulfation. In cold climates, increasing the diameter of the battery cables will reduce the voltage loss. Never discharge any 12-volt lead-acid battery below 10.5 volts because it can damage the battery. Provide adequate ventilation. High ambient temperatures above 80° F (or 26.7° C) will shorten battery life because it increases positive grid corrosion, growth and VRLA "thermal runaway"."

For lead acid batteries, lack of preventive maintenance, high temperature, fast recharging or overcharging causes a loss of water, which accounts for over 50% of the failures. sulfation from undercharging, electrolyte stratification (especially in taller batteries), using tap water, excessive temperatures or prolonged periods of non use account for approximately 85% of the deep cycle battery failures battery post or terminal corrosion, which cause charging and discharging problems. High ambient temperatures above 77° F (25° C) causing accelerated positive grid growth or corrosion, increased self-discharge, or thermal runway in AGM (Ca/Ca) VRLA batteries. For every increase of 18° F (10° C) above 77° F (25° C), the battery's life is cut in half due to positive grid corrosion or the self discharge rate is doubled. Misapplication, for example, using a starting battery in a deep cycle application, a motive deep cycle battery instead of a stationary for a UPS or an undersized battery (or battery bank) that causes discharges greater than the battery was designed for or will not produce enough capacity.

Do not locate batteries in place exposed to direct sun light, rain dust and adverse environments. Such exposure will cause damage to plastic components and may reduce battery life drastically. If the battery is not to be installed upon receipt, storage indoors is recommended. The batteries should be stored at a temperature of 15˚C-30˚C, in a clean, dry environment and provided with a freshening charge at intervals mentioned in point no.14. To prevent damage, do not stack wooden crates or battery packing cases one above the other,

Okaya batteries have expected shelf life as indicated in the table below . During the storage interval (i.e. between date of shipment and date of installation)for batteries stored at 270C, a freshening charge should be given once in every six(6) months. Storage at elevated temperatures will result in accelerated self-discharge as indicated below.

Here are some methods to try to recover permanently sulfated batteries:

Light Sulfation Equalize the battery.

Apply a constant current at 10% of the Amp Hour capacity rating for 48 to 120 hours, depending on the electrolyte temperature and capacity of the battery, at 14.4 VDC or more, depending on the battery type. Cycle (discharge to 50% and recharge) the battery a couple of times and test its capacity. You might have to increase the voltage in order to break down the hard lead sulfate crystals. If the battery gets above 45° C then stop charging and allow the battery to cool before continuing.

Heavy Sulfation

Replace the old electrolyte with distilled, deionized or demineralized water, let it stand for one hour, apply a constant current at 10% of the Amp Hour capacity rating at 14.4 VDC until there is no additional rise in specific gravity, remove the electrolyte, wash the sediment out, replace with fresh electrolyte (battery acid), and recharge. If the specific gravity exceeds 1.300, then remove the new electrolyte, wash the sediment out, and start over from the beginning with distilled water. You might have to increase the voltage in order to break down the hard lead sulfate crystals. If the battery gets above 45° C then stop charging and allow the battery to cool down before continuing. Cycle (discharge to 50% and recharge) the battery a couple of times and test capacity. The sulfate crystals are more soluble in water than in electrolyte. As these crystals are dissolved, the sulfate is converted back into sulfuric acid and the specific gravity rises. This procedure will only work with some batteries."

AGM batteries & their advantage "A newer type of sealed battery uses "Absorbed Glass Mats" or AGM between the plates. This is a very fine fiber boron-silicate glass mat. These type of batteries have all the advantages of gelled, but can take much more abuse. We sell the OKAYA AGM batteries. These are also called "starved electrolyte", as the mat is about 95% saturated rather than fully soaked. That also means that they will not leak acid even if broken.

AGM batteries have several advantages over both gelled and flooded, at about the same cost as gelled:

Since all the electrolyte (acid) is contained in the glass mats, they cannot spill, even if broken. This also means that since they are non-hazardous, the shipping costs are lower. In addition, since there is no liquid to freeze and expand, they are practically immune from freezing damage.

Nearly all AGM batteries are "recombinant", what that means is that the Oxygen and Hydrogen recombine inside the battery. They use gas phase transfer of oxygen to the negative plates to recombine them back into water while charging and prevent the loss of water through electrolysis. The recombining is typically 99+% efficient, so almost no water is lost.

The charging voltages are the same as for any standard battery - no need for any special adjustments or problems with incompatible chargers or charge controls. And, since the internal resistance is extremely low, there is almost no heating of the battery even under heavy charge and discharge currents.

AGMs have a very low self discharge from 1% to 3% per month is usual. This means that they can sit in storage for much longer periods without charging than standard batteries. The OKAYA batteries can be almost fully recharged (95% or better) even after 30 days of being totally discharged.

AGMs do not have any liquid to spill and even under severe overcharge conditions hydrogen emission is far below the 4% max specified for aircraft and enclosed spaces. The plates in AGMs are tightly packed and rigidly mounted and will withstand shock and vibration better than any standard battery.

Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down and increased as temperature goes up. The standard rating for batteries is at room temperature – 25°C (about 77°F). Battery charging voltage also changes with temperature. It will vary from about 2.74 volts per cell (16.4 volts) at -40°C to 2.3 volts per cell (13.8 volts) at 50°C.

Even though battery capacity at high temperatures is higher, battery life is shortened. Battery capacity is reduced by 50% at -30°C (-22°F) but battery LIFE increases by about 60%. Battery life is reduced at higher temperatures for every 10°C over 25°C, battery life is cut in half. This holds true for ANY type of Lead-Acid battery, whether sealed, gelled, AGM, industrial or whatever. This is actually not as bad as it seems, as the battery will tend to average out the good and bad times.

One last note on temperatures - in some places that have extremely cold or hot conditions, batteries may be sold locally that are NOT standard electrolyte (acid) strengths. The electrolyte may be stronger (for cold) or weaker (for very hot) climates. In such cases, the specific gravity and the voltages may vary.

All deep cycle batteries are rated in amp-hours. An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps x hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) x 0.333 (hours), or 6.67 AH. The accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured. Sometimes ratings at the 6 hour rate and 100 hour rate are also given for comparison and for different applications. The 6-hour rate is often used for industrial batteries, as that is a typical daily duty cycle. Sometimes the 100 hour rate is given just to make the battery look better than it really is, but it is also useful for figuring battery capacity for long-term backup amp-hour requirements.

Battery voltages "All Lead-Acid batteries supply above 2.1 volts per cell when fully charged. Batteries that are stored for long periods will eventually lose all their charge. This "leakage" or self discharge varies considerably with battery type, age, & temperature. It can range from about 1% to 15% per month. Generally, new AGM batteries have the lowest, and old industrial (Lead-Antimony plates) are the highest. In systems that are continually connected to some type charging source, whether it is solar, wind, or an AC powered charger this is seldom a problem. However, one of the biggest killers of batteries is sitting stored in a partly discharged state for a few months. A "float" charge should be maintained on the batteries even if they are not used (or, especially if they are not used). Even most "dry charged" batteries (those sold without electrolyte so they can be shipped more easily, with acid added later) will deteriorate over time. Max storage life on those is about 2-3 years.

Batteries self-discharge faster at higher temperatures. Lifespan can also be seriously reduced at higher temperatures - most manufacturers state this as a 50% loss in life for every 10 degrees F over a 25 degree cell temperature. Lifespan is increased at the same rate if below 25 degrees, but capacity is reduced. This tends to even out in most systems - they will spend part of their life at higher temperatures, and part at lower."

A WATT-HOUR is the unit of measure for electrical energy expressed as Watt x Hours.

OHM is a unit for measuring electrical resistance or impedance within an electrical circuit.

Ohm's Law expresses the relationship between volts (V) and amperes (A) in an electrical circuit with resistance (R). It can be expressed as follows: V= IR Volts (V) = Amperes (I) x Ohms (R). If any two of the three values are known, the third value can be calculated using the above equation.

In a lead-acid battery, the electrolyte is sulfuric acid diluted with water. It is a conductor that supplies water and sulfate for the electrochemical reaction:

The state of charge of a lead acid battery is most accurately determined by measuring the specific gravity of the electrolyte. This is done with a hydrometer. Battery voltage also indicates the level of charge when measured in an open circuit condition. This should be done with a voltmeter. For an accurate voltage reading, the battery should also be allowed to rest for a period sufficient to let the voltage stabilize.

When charging lead acid batteries, the temperature should not exceed 50°C. At this point the battery should be taken off charge and allowed to cool before resuming the charge process.

Yes! Deep cycle batteries are specially designed with denser active material and thicker plates to withstand deep discharge recharge service. They are also reinforced by envelope and glass mat separators to reduce shedding of the active material and damage from the jolting vibration of a boat on choppy water. Car batteries, on the other hand, use porous active material and thin plates so that high-amp energy can be quickly delivered for maximum starting power. Repeated cycling weakens the positive plates and makes the active material shed from the grids. Thus, in repeated deep discharge recharge applications, the capacity of the car battery drops below desired levels in about 50 cycles.

Yes, overcharging causes grid corrosion and reduces battery life. An automatic or timer switch charger are best.

It is easy to decide which deep cycle battery is required and how long it will operate your equipment before recharging is necessary.

Watts x Hours of Operation = Watt Hours

• Establish the loading of each piece of electrical equipment - this is expressed in watts and is stamped into the compliance plate attached to the electrical item.
• Determine the length of time (in hours) you intend to operate each piece of equipment between charges.
• Watts x Hours of Operation = Watt Hours
• Check the system voltage, e.g. 6 volts, 12 volts or 24 volts etc.
• The next stop is to determine the 'Ampere Hour' (AH) requirement that the battery must accommodate. You calculate this by dividing 'Watt hours' by the system voltage.

Example:

540 Watt Hours divided by 12 volts (step 3 voltage system) = 43 Ampere Hours." Correct Handling of batteries "To avoid shorting, metallic objects should not be placed on top of the battery. Batteries contain hydrogen gas and air in a volatile mixture which is easily ignited. Keep flames or sparks away from the battery at all times.

Batteries contain sulphuric acid. Never add acid to cells and keep acid away from eyes, skin, clothing or any other material which may become damaged.

If contamination occurs, use large amounts of water to neutralise and flush acid away.

Batteries are heavy ensure correct lifting procedures are used when moving batteries.

Correct Storing of Batteries "Batteries have a limited shelf life and when stored gradually lose their power to perform. On average, a fully-charged battery takes about 13 weeks to gradually discharge to less than its optimum operating level.

The rate of charge loss depends on battery type (low maintenance or maintenance free) and temperature conditions.

Charge loss becomes more evident when temperatures increase.

At 20 C low maintenance batteries lose approximately one half of one per cent of charge per day (30 percent in 60 days). At 30 C charge loss is usually double the rate for 20 C.

Under similar temperature conditions, maintenance free batteries lose their charge more slowly than low maintenance batteries. Excessive humidity will also accelerate charge loss.

A battery stored upright in cool and dry conditions is ideal.

Whilst in storage batteries that have not been recharged and allowed to go flat, may be permanently damaged. Recharging every four to eight weeks, depending on storage conditions, will restore batteries to ""as new"" condition.

No. But properly charging a deep cycle battery is a very important factor which can affect battery performance and life.

Batteries come in many different group sizes. A battery's group size simply determines it's length, width, height, and terminal configuration this has nothing to do with a battery's capacity. Regardless of the group size, two batteries are equal in power if the CCA [Cold Cranking Amp] ratings are the same. New technology enables a great deal of power to be put into smaller cases with today's new high capacity output design.

The battery's state of charge can be tested using a hydrometer or a voltmeter. A hydrometer will determine the specific gravity of the electrolyte in each cell, while a voltmeter will give you a voltage reading. There are some batteries that come with a state-of-charge indicator eye built in the battery's cover.

Heat is the number one killer of a battery. Although it increases the performance of the battery for the short term, life is drastically reduced over time. Heat increases the rate of evaporation, which causes a loss of water from the electrolyte. Extreme heat also increases the rate of self discharge and promotes the corrosion of the positive plate grids. OKAYA grid alloy reduces corrosion and extends battery life twice as long as standard battery designs.

The life of a battery is determined by a number of factors with the most important being proper maintenance. Amount of use, proper charging and climate are other elements that also need to be considered. A battery that is stored for prolonged periods of time without use or recharging can develop sulfation on the plates which will greatly reduce the time a battery will perform.

A cycle is simply discharging and recharging a battery once. Many companies advertise how many cycles a battery can achieve. One must be cautious when comparing these advertisements. How deep the battery was discharged, how the battery was recharged, what temperature the test was run and how a failure is defined all play into how many cycles a battery can withstand.

Sulfation refers to the process whereby a lead-acid battery loses its ability to hold a charge after it is kept in a discharged state too long due to the crystallization of lead sulfate.

There is no such thing as completely sealed flooded lead acid battery. All flooded lead acid batteries have vents that are continuously open to the environment. A "sealed" flooded battery generally refers to the cover design as being non accessible. Flooded batteries generally cannot be operated at an angle greater than 45 degrees.

An AGM battery is truly a sealed battery. Under normal operating conditions an AGM battery will not vent gases and is non spillable because the electrolyte is contained in the glass mat separators.

Mostly it would have been mentioned as Pro rata Warranty 24+6 :

Here 24 months means that any warranty on the battery covers defects in materials and workmanship from the date of installation or from the date of purchase by the customer. If any problem arises in the battery within this period it will be replaced free of cost only when the end user follows all Manufacturer maintenance instruction as in user manual. Also the battery should be serviced only by the Authorized Service Provider (ASP) approved battery manufacturers.

Whereas the additional six months means pro rata warranty. Under this warranty, if any part or item fails before the end of the pro rata warranty period, it is replaced at a cost that depends on the age of the part or item at the time of failure. The end user should bear the additional cost of the new part / item.

Note: The responsibility of battery maintenance (scheduled preventive maintenance) lies with the customer. In the event of missing the scheduled maintenance, the battery warranty will cease.