Rolls Marine Batteries have been the #1 choice of the people who ply the North Atlantic for over forty (40) years! Our heavy duty design, with a reputation for outlasting all competition, is known from Texas to Newfoundland. At sea where the life of the boat and her crew are at stake, take no chances, specify Rolls! No other manufacturer offers more for your money. Don't be fooled by some imitators who apply Marine labels to their automotive batteries. Marine service differs from automotive, requiring a battery that can stand up when exposed to cycling service. Lights, refrigeration blowers, motors, radio, and other electrical equipment results in cycling service, meaning the battery is constantly being charged and discharged! An automotive battery does not have the stamina required to perform cycling service and will not withstand the abuses of marine service. Thus, any money saved on "less expensive" batteries will result in less reliable service and a much reduced operating life. Engine cranking (or starting) batteries require high current output. In marine service, the batteries should have much greater capacity than normally required for the same horsepower "shore-based" equipment. In the event of starting trouble, a reserve of cranking capacity should be available, otherwise, the batteries will be dead before the trouble is corrected! Take no chances, choose Rolls, the positive choice for life!
Note: All pricing is the manufacturers list price, call or e-mail us for Boat Electric's Prices.
For additional technical information, go to the Surrette Bulletin section
Surrette/Rolls manufacturers a complete line of 8 volt batteries as well as 2 volt cells. Contact us for additional information.
For additional technical information, go to the Surrette Bulletin section
Surrette Technical Bulletins:
How many times have you heard the expression, "The Battery Won't Take A Charge" or "The Battery Won't Hold A Charge" ? More often than not, the culprit is hardened sulfate on the battery plates. Below we will attempt to explain what that means, what the causes are, and some measures to prevent the sulfate from permanently damaging your battery.
Let's look inside a battery cell. Basically, there are the positive plates, the negative plates, separators (to keep the plates apart), and electrolyte (sulfuric acid and water).
In normal use, battery plates are getting sulfated all the time. When a battery is being discharged the lead active material on the plates will react with the sulfate from the electrolyte forming a lead sulfate on the plates. When there is no lead active material and or sulfate from the electrolyte remaining the battery then is completely discharged. After a battery reaches this state, it must be recharged. During recharge, the lead sulfate is re-converted into lead active material and the sulfate returned to the electrolyte.
When the sulfate is removed from the electrolyte the specific gravity is reduced and the reverse takes place when the sulfate is returned to the electrolyte. This is why the state of charge can be determined with the use of an hydrometer.
If a battery is left standing in a discharged condition the lead sulfate will become hard and have a high electrical resistance. This is what is normally called a sulfated battery. The lead sulfate may become so hard that normal recharging will not break it down. Most charging sources, engine alternators and battery chargers, are voltage regulated. Their charging current is controlled by the battery's state of charge. During charging, battery voltage rises until it meets the charger's regulated voltage, lowering the current output along the way.
When hard sulfate is present, the battery shows a false voltage, higher than it's true voltage, fooling the voltage regulator into thinking that the battery is fully charged. This causes the charger to prematurely lower it's current output, leaving the battery discharged. Charging at a higher than normal voltage and low current may be necessary to break down the hardened sulfate.
Hardened sulfate also forms in a battery that is constantly being cycled in the middle of its capacity range (somewhere between 80% charged and 80% discharged), and is never recharged to 100%. Over time, a portion of the plate's active materials turns into hard sulfate. If the battery is continually cycled in this manner, it will lose more and more of its capacity until it no longer has enough capacity to perform the task for which it was intended. An equalizing charge, applied routinely every three to four weeks, should prevent the sulfate from hardening.
In both cases, the fact that the battery "won't take a charge" is a result of improper charging procedures which allowed the sulfate to harden. In most instances, it is possible to salvage a battery with hardened sulfate. The battery should be charged from an outside source at 2.6 to 2.7 - volts per cell and a low current rate (approximately 5 Amps for small batteries and 10-Amps for larger ones) until the specific gravity of the electrolyte starts to rise. (This indicates that the sulfate is breaking down.) Be careful not to let the internal temperature of the battery rise above 125o F. If it does, turn the charger off and let the battery cool. Then, continue charging until each cell in the battery is brought up to full charge (nominal 1.265 specific gravity or higher). This time needed to complete this recharge depends on how long the battery has been discharged and how hard the sulfate has become.
The next time your batteries don't seem to be taking or holding a charge, check the specific gravity with a hydrometer. If all cells are low even after a long time on charge, chances are you've got some hardened sulfate that has accumulated on the plates. By following the instructions outlined above, the problem may be corrected.
With a sealed battery the same problem can exist.
Unfortunately hydrometer readings cannot be taken to determine the problem. If
you subject a sealed battery to overcharging you may lose the electrolyte and
ruin the battery.
Series 400 & 500 (4000 & 5000 Rolls)
for Deep Cycling
The best method is to determine the requirements of the boat. Below only serves as a rough guide and would be considered as the minimum requirements of the vessel.
The rules may change with the addition of an Inverter or other electrical equipment. On a 12 volt system divide 5 into the wattage of the Inverter to determine the size batteries required. On a 24 volt system divide by 10.
If the Inverter is to be run for more than a maximum of 15 minutes at close to full capacity, a larger battery bank will be required!
The exception may be if power is being supplied to the batteries from an alternator or other source.
Depending on the size of the boat it may be desirable to break the house batteries up into 2 or more systems for safety reasons. The essentials should be on one bank and the non-essentials on the other bank. Essentials are considered anything to do with safety, such as electronic equipment. Non-essentials are such things as an electrical refrigerator.
On a 12 volt system when 2 batteries are used to obtain the capacity for the house bank the question usually arises as to whether to use two 6 volts in series or two 12 volt in parallel. With two 12 volts in parallel if one battery should fail, the battery can be disconnected and still have a "live" system. With two 6 volts this is not so.
When installing two batteries in parallel the batteries must be:
Connections must be:
The starting battery or batteries should be isolated from the house batteries, and used only for starting the engine. This battery or batteries can be a Series 300 (3000 Rolls), or a good quality automotive type. The Series 400 and 500 will normally work fine for starting, but in many cases the user is paying more money than is necessary. However, the Series 400 & 500 will pay for itself due to it's heavy construction and long life!
So-called new no maintenance batteries with a marine label are not that much different than automotive no-maintenance batteries except the price. The reference to Gelled (Prevailer) has caused confusion. The gel only serves to hold the battery electrolyte captive and in deep cycle service it results in lower capacity than their rating. Batteries made with this construction are usually acid starved without sufficient electrolyte to activate the plates. The result is low capacity size for size.
By sealing the battery, there is no practical way of determining the battery's condition if the battery can't be checked with a hydrometer, the boat owner could be starting a cruise with low batteries; in an emergency it could result in battery failure just when the battery power is needed most.
The buyer of a Gelled type battery should be cautioned that the voltage setting of the regulator may have to be changed. The Prevailer has a 14.1 maximum volt limitation. Most alternators are preset at 14.2 to 14.5 volts and must be reduced in order to protect Gelled electrolyte batteries. Some distributors of Gelled type batteries have suppressed the fact that the ship's charging system may require an expensive modification to accommodate this type battery.
Most so-called sealed batteries are assembled in gray propylene cases - same as most automotive batteries. Rolls uses only black rubber containers on all series 4000, including the smaller size marine Batteries. White propylene cases are used only on our 3rd line series.
Promoters of these types of batteries are highly sales motivated. They fail to put the boat owner on notice that, in the event of improper voltage regulator setting, the battery could dry out and, if so, there would be no way to replace the water so that the battery could continue to function.
They refer to cranking power. They have no more than the average maintenance free automotive battery, which depends on a multiple of thin plates - the thinner the plates, the shorter the battery life, and the less able to stand abuse and overcharging.
The maintenance-free automotive batteries normally have plates as thin as .0500 thick, with low density porous active material (oxide) which does not lend itself to deep cycling or overcharging. It does have one advantage: it uses less lead and is a cheaper way to make a battery.
With low capacity characteristics inherent in Gelled electrolyte batteries, their claims of faster recharge ability exist partly because there is less capacity to return to the battery. These claims are immeasurable because the only state of charge measurement is surface voltage which is not an accurate indicator for calcium lead alloy batteries. Because Gelled batteries are acid starved they have less capacity and also less problems with sulfation.
The positive plates in a lead acid battery are the limiting factor in life expectancy in deep cycling marine service. The so-called new sealed battery has very fragile thin plates no different than common automotive batteries.
Gelled batteries, such as the Prevailer battery, costs approximately 40% more than Rolls Marine Series 4000 and 100% more than American made automotive batteries. They use a cheap polypropylene case compared to rubber and they are clearly designed for float operation and a periodic deep cycling. Periodic deep cycle normally is not suitable or will not qualify as a deep cycle battery. Most automotive batteries qualify for periodic deep cycle service.
The above is only a brief comparison to reflect the fact that there is little if any difference, except the higher price, with the average North American car battery.
There is considerable confusion in the marketplace concerning marine batteries. The confusion centers around what is a marine battery? What is the difference between a marine, deep cycle, automotive and R./V. (Recreational Vehicle)? How to maintain, etc..
Many battery manufacturers sell their product to the marine trade by supplying their regular automotive and truck batteries with marine labels. This is difficult for the average layman to detect.
Rolls definition of a marine battery is one that is designed for maximum reliability. Remember, there are no service stations at sea. Maximum reliability is achieved by utilizing heavy positive and negative plating, dense active material, reinforced grid design, premium insulation which usually includes a thick woven glass mat, cell protector, rubber container, heavy intercell connections and on larger batteries multi-cell construction.
The majority of failures in lead acid batteries are contributed to the positive plates. The grid which is part of the plate is referred to as the current carrying conductor. The plate consists of the grid plus the active material. The active material chemically produces electricity which is conducted by the grid via inter cell connectors to the terminals.
Every time the average battery is discharged a small portion of the active material becomes inactive or lost because of expansion. On recharging the current chemically converts the active material from a lead sulfate to lead dioxide. This same current also converts a small portion of the lead in the grid to lead dioxide. This is sometimes referred to as a grid corrosion.
By now, you have probably guessed why the heavy positive plates and the reinforced grid design. The heavy positive plates provides more active material. By using a denser active material, more material can be held within a given space.
The reinforced grid design is accomplished by providing more metal in the grid. More metal can be lost from grid corrosion without harmfully affecting the battery. Overcharging will accelerate positive grid corrosion. Starting batteries are subjected to overcharge conditions when the engine is running. The electrical system is designed to replace a little more current than is lost via self discharge.
We often use the expression "The chain is only as strong as the weakest link". This is true in battery engineering. That is why a high quality marine battery will utilize high quality insulation to compliment the heavy plate construction. In most cases a thick woven glass mat will be placed against the positive plate. This is used to maintain the active material on the grid which extends the useful life of the battery. The glass mat is also referred to as a retaining mat. The best insulation is PVC, rubber or polyethylene. Glass matting should be a minimum of 0.020 thick to be effective.
The cell protector, made of perforated vinyl, fits on top of the cell immediately under the vent opening. The protector mat prevents damage to the insulation when a hydrometer is inserted into the vent opening.
Rubber containers are desirable in marine deep discharge type batteries. Rubber is more rigid and does not have the tendency to bulge. This is most important in deep discharge batteries.
Heavy intercell connectors are important to provide that extra margin of safety during high discharge. Thin intercell connectors used in solid top construction may melt under severe loads.
A good quality marine battery is initially expensive although inexpensive when considering the life expectancy. Multi-cell construction can be repaired in the event of damage. Solid top construction cannot.
Maintenance-free is the worst choice. If the electrical system malfunctions, the electrolyte may boil out. If maintenance-free, there is no way of replacing it. There is no way of checking the battery's electrolyte to determine whether the battery is in a charged or discharged condition. Yes, you will have the first signs of trouble when it starts failing. Okay, if you are alongside the dock, but tragic if you are still at sea or beginning a planned weekend. Even after repairs to a malfunctioned electrical system, the maintenance-free battery, if discharged will quite often have to be replaced. In many instances they will not accept recharging. Most maintenance-free batteries have calcium in the lead grids which forms calcium oxide on the surface of the grid when the battery is discharged. The calcium oxide forms a barrier between the grid and active material which makes recharging very difficult.
Most buyers of marine batteries compare products on the market by the number of plates, 20 hour capacity, reserve capacity, and the cranking performance. Before continuing, I would like to explain the meaning of the last three items.
The 20 hour rating is the capacity of the battery determined over 20 hours at 80of (26.7oC). A battery rated at 100 A.H. for 20 hours means that if you divide 20 into 100 the battery can be discharged at 5 amperes continuously for 20 hours. Likewise, if the rating was at 8 hours then divide 8 into 100. This would mean that the battery could discharge 12.5 amperes for 8 hours.
Marine batteries are usually rated at the 20 hour or 8 hour rating. The 8 hour rating is usually approximately 82% of the 20 hour rating.
The reserve capacity is defined as the number of minutes a battery can be discharged at 25 amperes. The temperature again is 80oF or 26.7oC.
The cranking performance is a measure of the maximum load a battery can withstand for 30 seconds at 0oF or 17.8oC. The cut off voltage is 7.2 volts for a 12 volt battery.
The cranking performance of a battery is determined by the square inches of surface area of the positive plates.
The 20 hour, 8 hour and reserve capacity of a battery is determined by the amount of cubic inches of active material. To obtain the maximum in these ratings the battery would be designed with fewer, but much heavier plates.
In order to demonstrate the confusion that rating presents to the layman, I have made a comparison between Rolls and a leading R.V............ type battery.
Both batteries are approximately the same dimension except the Rolls is higher. The R.V....... is a little longer because of the rope handles. Both batteries will deliver approximately 90 A.H. when new. But this is where the similarities stop.
The Rolls is conservatively rated because of the thickness of the plate and density of the active material. Because of the thickness and density the electrolyte cannot penetrate the inner service of the plate. However, as the Rolls ages this unused material comes into use and the battery actually increases in capacity. When both batteries are subjected to hard service the R.V....... type drops off in capacity very quickly. The Rolls increases in capacity and maintains this capacity over along life span.
The Rolls does not have as good a cranking performance because of the lower exposed plate area and also due to the thick woven glass mat. The thick woven glass mat retards the flow of electrolyte and thus reduces the cranking performance by approximately 10%. However, the glass mat adds to the life expectancy and reliability of the battery. The R.V....... battery has a thin glass mat which is ineffective.
If the initial performance was the guide then the R.V....... would be the better buy. However, when you think of the long term investment the Rolls is by far the better buy. Also, do not forget about the safety of a reliable product when at sea. Remember "quality hurts only once".
When comparing batteries ask about the ratings
as this will determine the physical size of a battery you will need. But do not
stop, ask additional questions. It is most important that you know the type of
insulation. Cellulose (impregnated paper) is the least desirable. Ask about the
thickness of the glass mat. It should be nothing less than 0.020. Ask about
plate thickness and height. The weight of the battery is a good guide as to the
thickness and height of the plates. A thin plate battery will weigh less. If
your dealer is knowledgeable and is not trying to confuse you, he will have the
Prior to placing batteries into winter storage make certain the electrolyte level is approximately 1.2" (30.4mm) above the top of the separators. The electrolyte level in very cold batteries will be lower than normal, so let batteries warm to a normal temperature before judging electrolyte levels.
Once the electrolyte level is correct ensure that the batteries are fully charged. Ensure that the battery tops are clean and dry. See Information Bulletin 501 & 507.
Now the choice is whether to leave the batteries aboard your boat or remove and store in a cool dry area. If the batteries are stored aboard the boat, disconnect the terminal cables. This will prevent premature discharge of the batteries due to a ground in the electrical circuits or failure to turn a piece of electrical equipment off.
If the batteries become discharged, the electrolyte can freeze when stored below +20 o F (70oC). Below shows temperatures at which electrolyte, in various states of charge, starts to freeze.
A 3/4 charged battery is in no danger of freezing. Therefore, batteries should be kept at least 3/4 charged, especially during winter weather.
The frequency of checking batteries depends greatly on temperature. The effect of temperature on self discharge for the average fully charged, new, conventional battery in good condition is approximately as follows:
A fully charged battery stored at 80oF (26.7oC) will take 30 days before it self discharges 25 percent. At 50oF (10oC) the time period increases to 100 days. This will give you an idea of how often a battery should be checked.
Some makes of batteries will have a higher and some a lower rate of self discharge. This depends on the method of manufacture and purity of materials used
The battery is a major factor in regulation of the charging current by its change in counter voltage. Anything which affects the battery or regulator such as temperature, sulfation, etc... affects the charging current.
Low water consumption is an indication of proper regulator setting. When a battery uses more than 30-60 ml of water per cell per 40 hours of operation the regulator is set too high. The ideal voltage setting for a regulator may be defined as that setting which will keep the battery at or near full charge with a minimum use of water.
The correct voltage setting at 26.7C when using Rolls Marine Batteries is between 2.33 VPC and 2.36 VPC or 14 to 14.2 volts on a 12 volt system. Batteries that are not being exercised regularly the voltage setting should be reduced to approximately 2.17 VPC or 13.02 volts on a 12 volt system. This is common in a standby system or batteries left on charge over the winter months with the charger supplying the vessels requirements.
Some boat operators will charge at a higher voltage for a short period of time. This is referred to as an equalize charge. This is an acceptable procedure for batteries that are being cycled daily but certainly not necessary will reduce the life of the battery.
In most instances the best trade off for maximum battery life and the absence of problems in marine applications is a multi-bank, dedicated correct fixed voltage system. This means heavy duty alternators designed for marine application and voltage regulation that does not drop below the desired level when the batteries approach full charge.
If charging voltage of 14-14.2 cannot be maintained the recharge time will increase. Voltage regulators with pronounced temperature voltage compensation curves as used in many automotive type systems are not usually suitable for recharging batteries in deep cycle applications. The alternator output voltage may fall below the necessary minimum long before the battery reaches full charge.
Multi-battery isolators are commonly used in charging systems. Beware of attempts to install isolators in systems using unmodified, internally mounted and internally sensed voltage regulators. The charging voltage will be too low which will lead to battery sulfation and possible battery failure.
Avoid paralleling or placing batteries in series that are of a different brand, size and age. Premature battery failures will result.
A serviceable battery's ability to resist charging increases as it approaches full charge and decreases as it becomes discharged. This is due to the battery's higher counter voltage or resistance as it approaches full charge. As a battery becomes more nearly charged a higher voltage would be required to maintain the same charging current. On a properly regulated charging system the charging current approaches zero as the battery approaches a fully charged condition. A battery with a defective cell would have lower counter voltage and thus the charging current would be at a higher than normal level. Of course the good cells would soon fail due to overcharging and also consume more water than normal.
Do not completely discharge a deep cycle battery if it can be avoided. The deeper the discharge the less life you will obtain from the battery. the ideal method of operation in to charge and discharge the batteries through the middle range of their capacity (50% - 85%). The reason for this is that the charge acceptance rate is fairly high in the middle range of the capacity. From 85% to 100% requires a small charging current over a longer period of time. This is usually undesirable in a sail boat as it would require running the engine for a long period of time. No problem if you are connected to shore power using a high quality marine charger.
At least once a month the battery system must be fully charged when operating in the middle range of the battery capacity. During each discharge a little more lead sulfate accumulates. If this lead sulfate is allowed to remain for too long a period it will become very difficult to remove. The reason is that the lead sulfate will become hard and have a high electrical resistance. This is what is normally called a sulfated battery. The lead sulfate may become so hard that normal recharging will not break it down. This is the reason many sail boat owners complain at the end of the season that their batteries will not accept a charge.
See Information Bulletin 501.
The amount of recharge a battery needs can be determined by measuring the specific gravity with a hydrometer. The chart below shows the approximate "percent of charge" at various specific gravity values at 26.7 C.
On a manual charging system the charging current at less than 75% charged can be 25% of the 20 hour rate. The rate can even be higher below 50% charged. Once the battery approaches 75% charged reduce to 10% of the 20 hour rate. At 85% reduce the rate to 3% of the 20 hour rate. At 100% the charge is discontinued. A well regulated fixed rate system will do this automatically.
So called low-maintenance batteries are not all the same! There is a vast difference from one manufacturer to another.
While they are designed to go further without adding water, water can be added and the battery cell condition can be checked. This is not possible with most maintenance free batteries.
With maintenance free, if the electrical system malfunctions, the electrolyte may go dry, and there is no way of replacing it! There is no way of checking the electrolyte level, nor is there a reliable way of determining the state of charge of the battery. Only an experienced technician can determine the state of charge with a high quality voltmeter. Yes, you will have the first of trouble when the battery starts to fail. Okay if you are alongside the dock, but tragic if you are still at sea or beginning a planned weekend.
Many maintenance free batteries will not accept a charge if totally discharged as they contain calcium oxide between the grid and the active material. The calcium oxide has a high electrical resistance and confuses the alternator or charger into thinking the battery is charged!
Good marine practice dictates periodically checking the battery (or batteries) before putting out to sea.
|Specific Gravity (cor..... to 80oF/26C)||Freezing Temp|
|1.280 Spec. Grav......(cor..... to 80oF/26C)||-92F (-69C)|
|1.265 Spec. Grav......(cor..... to 80oF/26C)||-71.3F (-57.4C)|
|1.250 Spec Grav......(cor..... to 80oF/26C)||-62F (-52.2C)|
|1.200 Spec Grav......(cor..... to 80oF/26C)||-16F (-26.7C)|
|1.150 Spec. Grav......(cor..... to 80oF/26C)||+5F (-15C)|
|1.100 Spec. Grav......(cor..... to 80oF/26C)||+19F (-7.2C)|
The state of charge of a battery can be measured with a hydrometer. The chart below shows the approximate "percent of charge" corrected for temperature at various specific gravity values.
|Charged||Specific Gravity||Open Circuit Voltage|
Determining state of charge by voltage is more difficult as there must be no load or surface voltage present.
When taking specific gravity measurements, it is important to correct for temperature to get a true reading. As a rule of thumb, specific gravity will change by 0.0003 for each ten degrees Fahrenheit change in temperature above or below 77 F (25 degrees C). Below 77F subtract from readings and above 77F add to the readings. As an example a reading of 1.265 at 67F corrected for temperature would be 1.262 and a reading of 1.265 at 87F corrected for temperature would be 1.268.
It is recommended that fully charged gravity and voltage readings be taken of each cell every month and compared with readings from the preceding period. The readings will indicate any marked difference in battery condition as well as differences between cells. A good rule of thumb is if there is 0.025 points or less between the high and low cell the battery is not defective. Low readings would indicate the battery being discharged.
Sometimes the battery may be operated between the middle range or it's capacity due to load demands and or lack of charging time. At least once every three to four weeks the battery system must be fully charged. During discharge sulfate is formed. If the sulfate is allowed to remain for too long a period it will become very difficult to remove and the battery system will not accept a charge.
For more information see bulletin #501.
The charging system can have a profound effect on the life of the battery. A high voltage setting can cause excessive gassing and water loss. Eventual damage to the battery system will take place. A low setting will leave the batteries in an under charged condition resulting in a loss of capacity and eventually the battery system may not take a charge. A proper setting will result in a minimum of water consumption and still able to maintain the batteries at full charge.
For more information see bulletin #507.
Remember batteries may expel explosive gases. Keep sparks, flames, burning cigarettes or any other ignition sources away from the battery system at all times. Always wear a face shield when working near batteries.
|Charged||Specific Gravity||Open Circuit Voltage|
|Charged||Specific Gravity||Open Circuit Voltage|