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  Gelled Electrolyte (gel) and Absorbed Glass Mat (AGM) Batteries


Valve-regulated lead-acid (VRLA) technology encompasses both gelled electrolyte and absorbed glass mat (AGM) batteries. Both types are valve-regulated and have significant advantages over flooded leadacid products.

More than a decade ago, East Penn began building valve-regulated batteries using tried and true technology backed by more than 50 years experience. East Penn¡¯s unique computer-aided manufacturing expertise and vertical integration have created a product that is recognized as the highest quality, longest lived VRLA battery available from any source.

East Penn¡¯s gel and AGM batteries are manufactured to tough quality standards. East Penn manufactures high power gel and AGM batteries with excellent performance and life.


VRLA batteries can be substituted in virtually any flooded lead-acid battery application (in conjunction with well-regulated charging), as well as applications where traditional flooded batteries cannot be used. Because of their unique features and benefits, VRLA batteries are particularly well suited for:

Deep Cycle, Deep Discharge Applications
* Marine Trolling ? Electronics ? Sailboats
* Electric Vehicles ? Wheelchairs ? Golf Cars
* Portable Power ? Floor Scrubbers
* Personnel Carriers ? Marine & RV House Power
* Commercial Deep Cycle Applications

Standby and Emergency Backup Applications
* UPS (Uninterrupted Power Systems) ? Cable TV
* Emergency Lighting ? Computer Backup ? Solar Power
* Telephone Switching ? Village Power

Unusual and Demanding Applications
* Race Cars ? Air-transported Equipment
* Off-road Vehicles ? Wet Environments
* Marine & RV Starting ? Diesel & I.C.E. Starting

What is a gel battery?
A gel battery is a lead-acid electric storage battery that:
* is sealed using special pressure valves and should never be opened.
* is completely maintenance-free.*
* uses thixotropic gelled electrolyte.
* uses a recombination reaction to prevent the escape of hydrogen and oxygen gases normally lost in a flooded lead-acid battery (particularly in deep cycle applications).
*is non-spillable, and therefore can be operated in virtually any position. However, upside-down installation is not recommended.
* Connections must be retorqued and the batteries should be cleaned periodically.

What is an AGM battery?

An AGM battery is a lead-acid electric storage battery that:
* is sealed using special pressure valves and should never be opened.
* is completely maintenance-free.*
* has all of its electrolyte absorbed in separators consisting of a sponge-like mass of matted glass fibers.
* uses a recombination reaction to prevent the escape of hydrogen and oxygen gases normally lost in a flooded lead-acid battery (particularly in deep cycle applications).
* is non-spillable, and therefore can be operated in virtually any position. However, upside-down installation is not
* Connections must be retorqued and the batteries should be cleaned periodically.

How does a VRLA battery work?

A VRLA battery is a ¡°recombinant¡± battery. This means that the oxygen normally produced on the positive plates of all lead-acid batteries is absorbed by the negative plate. This suppresses the production of hydrogen at the negative plate. Water (H2O) is produced instead, retaining the moisture within the battery.

It never needs watering, and should never be opened as this would ¡°poison¡± the battery with additional oxygen from the air. Opening the battery will void the warranty.

What are the differences between gel batteries and absorbed glass mat (AGM) batteries?

Both are recombinant batteries. Both are sealed valve-regulated (SVR) ¨C also called valve-regulated lead-acid (VRLA). AGM batteries and gel batteries are both considered ¡°acid-starved¡±. In a gel battery, the electrolyte does not flow like a normal liquid. The electrolyte has the consistency and appearance of petroleum jelly. Like gelled electrolyte batteries, absorbed electrolyte batteries are also considered non-spillable ¨C all of the liquid electrolyte is trapped in the sponge-like matted glass fiber separator material.

The ¡°acid-starved¡± condition of gel and AGM batteries protects the plates during heavy deep-discharges. The gel battery is more starved, giving more protection to the plate; therefore, it is better suited for super-deep discharge applications.
Due to the physical properties of the gelled electrolyte, gel battery power declines faster than an AGM battery¡¯s as the temperature drops below 32ºF. AGM batteries excel for high current, high power applications and in extremely cold environments.

What is the difference between VRLA batteries and traditional wet batteries?

Wet batteries do not have special pressurized sealing vents, as they do not work on the recombination principle. They contain liquid electrolyte that can spill and cause corrosion if tipped or punctured.

Therefore, they are not air transportable without special containers.They cannot be shipped via UPS or Parcel Post or used near sensitive electronic equipment. They can only be installed ¡°upright.¡±Wet batteries lose capacity and become permanently damaged if:
* left in a discharged condition for any length of time (due to sulfation). This is especially true of antimony and hybrid types.
* continually over-discharged, due to active material shedding.

This is especially true of automotive starting types. Our gel cells have triple the deep cycle life of wet cell antimony alloy
deep cycle batteries, due to our unique design. The shelf life of a VRLA battery is seven times higher than the shelf life of a deep cycle antimony battery.

How do VRLA batteries recharge? Are there any special precautions?

While our VRLA batteries accept a charge extremely well due to their low internal resistance, any battery will be damaged by continual under- or overcharging. Capacity is reduced and life is shortened. Overcharging is especially harmful to any VRLA battery because of the sealed design. Overcharging dries out the electrolyte by driving the oxygen and hydrogen out of the battery through the pressure relief valves. Performance and life are reduced. If a battery is continually undercharged, a power-robbing layer of sulfate will build up on the positive plate, which acts as a barrier to recharging. Premature plate shedding can also occur.Performance is reduced and life is shortened. Therefore, it is critical that a charger be used that limits voltage.

The charger must be temperature-compensated to prevent underor overcharging due to ambient temperature changes. (See Charging Voltage vs. Ambient Temperature chart on page 11.)

Important Charging Instructions

The warranty is void if improperly charged. Use a good constant potential, temperature-compensated, voltage-regulated charger. Constant current chargers should never be used on VRLA batteries.

Can VRLA batteries be installed in sealed battery boxes?

NO! Never install any type of battery in a completely sealed container. Although most of the normal gasses (oxygen and hydrogen) produced in a VRLA battery will be recombined as described above, and not escape, oxygen and hydrogen will escape from the battery in an overcharge condition (as is typical of any type battery).

For safety¡¯s sake, these potentially explosive gasses must be allowed to vent to the atmosphere and must never be trapped in a sealed battery box or tightly enclosed space!

Can our VRLA batteries be used as starting batteries as well?

Our VRLA batteries will work in SLI (Starting, Lighting and Ignition) applications as long as the charging voltage is regulated to the appropriate values from the tables on page 11. Many vehicle regulators are set too high for gel batteries; therefore, the charging system may require adjustment to properly recharge a gel battery for best performance and life.AGM batteries excel in low temperature, high current applications such as cold weather starting.

What do the ratings and specifications signify for this line?

All ratings are after 15 cycles and conform to BCI specifications.CCA = Cold Cranking Amperes at 0¡ãF (¨C17.8¡ãC) Cold cranking amperes equal the number of amperes a new, fully charged battery will deliver at 0¡ãF (¨C17.8¡ãC) for thirty seconds of discharge and maintain at least 1.2 volts per cell (7.2 volts for a 12-volt battery).
CA = Cranking Amperes at 32¡ãF (0¡ãC)
Same as above, tested at 32¡ãF (0¡ãC).
RC = Reserve Capacity at 80¡ãF (27¡ãC)
The reserve capacity is the time in minutes that a new, fully charged battery can be continuously discharged at 25 amperes and maintain at least 1.75 volts per cell (10.5 volts for a 12-volt battery).

Minutes discharged at 50, 25, 15, 8 and 5 Amperes Minutes discharged is the time in minutes that a new, fully charged
battery will deliver at various currents and maintain at least 1.75 volts per cell. These are nominal or average ratings.
Ampere Hour Capacity at 20, 6, 3 and 1 Hour Rates Ampere hour capacity is a unit of measure that is calculated by
multiplying the current in amperes by the time in hours of discharge to 1.75 volts per cell. These are nominal or average ratings.

10 amperes for 20 hours (10 x 20) = 200 Ah @ the 20-hour rate
8 amperes for 3 hours (8 x 3) = 24 Ah @ the 3-hour rate
30 amperes for 1 hour (30 x 1) = 30 Ah @ the 1-hour rate

Therefore, if you have an application that requires a draw of 17 amperes for 3 hours, you would need a 51 Ah battery (@ the 3 hour rate)¡­(17 x 3 = 51). However, this is 100% of the capacity of this 51 Ah battery.

Most system designs will specify a battery that will deliver a minimum of twice the capacity required. This means the battery
will discharge to 50% of its capacity. Using a 50% depth of discharge (versus 80% or 100%) will dramatically extend the life
of any battery. Therefore, when helping to specify a battery for a system, choose a battery with at least twice the capacity required for best performance. If 50 Ah is required, specify at least a 100 Ah battery.

Independent Laboratory Testing BCI 2-Hour Life
Group Size ¡°27¡± Batteries East Penn Gel and AGM vs. Competitor
This chart compares the cycles run until the battery capacity dropped to 50% of the 15th cycle¡¯s capacity (on discharges at the 2-hour rate to a 10.5-volt cutoff).



Charging Current vs.Charging Time
Shown is the current needed to charge a battery from 0% to 90% state of charge in a given time. Or time required to change a battery from 0% to 90% state of charge at a given current. For example, to charge an 8G8D (curve H) to 90% in
3.5 hours, 100 amperes are required; at 35 amperes, it would take 10 hours

VRLA Battery Voltage During Constant Current Discharge Voltage vs. Percent Discharged



Gel Percent Cycle Life vs. Recharge Voltage
This chart shows the effect on life of overcharging a gel battery.
(e.g.: Consistently charging at 0.7 volts above the recommended level reduces life by almost 60%!)


What are the features and benefits that make East Penn¡¯s VRLA batteries unique?
East Penn Expertise

East Penn builds VRLA batteries to the highest standards. Our manufacturing process features improved controls using state-of-the art computers and the latest manufacturing technology and equipment. Therefore, the VRLA batteries produced by East Penn consistently meet the highest quality performance and life standards.

Ultrapremium Sealing Valve

A critical feature of any VRLA battery, gelled or absorbed, is the quality of the sealing valve. Not only must the valve keep the cell pressurized and safely release excessive pressure and gas due to overcharging, but it must also keep the cell from being contaminated by the atmosphere. Oxygen contamination will discharge a VRLA battery and eventually ruin the battery.

Our valves are UL recognized and 100% tested after manufacturing.The benefit is reliable performance and long life.
Spillproof and Leakproof A major advantage of VRLA batteries is their spillproof and leakproof feature. However, all VRLA batteries are not created equal in their degree of non-spillability. Some manufacturer¡¯s AGM batteries are unevenly filled. Over-saturation of the separators leaves liquid electrolyte that could spill. Under-saturation could lead to premature failure.
Some gels do not set properly; they remain liquid and can leak or spill. Our exclusive gel electrolyte is formulated, mixed and controlled to assure proper ¡°set¡± in every battery. East Penn¡¯s computer-controlled gel mixing and filling equipment ensures homogenization of the mix. This assures a gel battery that will not spill or leak. This feature allows our gel cell to be operated in virtually any position. However, we do not recommend an upside-down orientation. The AGM filling process assures that each cell is saturated with the maximum amount of electrolyte that can be held by the separators, without leaving excess electrolyte that could spill or leak.

Exclusive Gel Formula

The gelled electrolyte is another critical element in this type of battery. Our gelled electrolyte contains sulfuric acid, fumed silica, pure demineralized, deionized water, and a phosphoric acid additive. The phosphoric acid is a key reason that our batteries deliver dramatically longer cycle life than leading gel competitors and 3 times longer cycle life than traditional wet cells.

Exclusive AGM Electrolyte

Our AGM electrolyte contains high purity sulfuric acid and absolutely pure totally demineralized, deionized water to increase battery performance. Since the designs are ¡°acid-starved¡± to protect the plates from deep discharge, the acid concentration can drop to nearly zero during an extremely deep discharge. Substances that will not dissolve in acid may become soluble when the concentration drops this low. Upon recharge, these dissolved substances crystallize out
of the electrolyte, potentially destroying the battery. Our electrolyte prevents these events.

Exclusive Computerized Gel Mixing

Proper gel mixing is critical to life and performance. Consistency in mixing means consistent reliability. We have designed and built the newest, state-of-the-art gel battery manufacturing facility in the world. An example is our proprietary computerized gel mixing operation. Our exclusive formula is mixed using computer control in every stage of the process. Computer control delivers superior consistency for gel battery performance that is unequaled. Our temperature-controlled process and specially designed equipment assure a homogenous gel. It is important to note that our equipment was designed by our engineers specifically for gel mixing¡­ even down to the contour of the tank bottoms and feed pipe locations.

No other battery manufacturer has comparable equipment. Multi-Staged Filling/Vacuuming Operation. Most other manufacturers fill their gel cells in a one step process, vibrating the battery with hopes of releasing most of the air pockets.
This system is less than perfect and leaves voids or air pockets at the critical gel-to-plate interface. These voids are non-reactive and reduce overall battery performance.
Our process fills and vacuums each cell several times. This multi-step process assures complete evacuation of air and complete gel-toplate interface. Our computerized process also weighs every battery before and after filling as a check for proper gel levels. The benefit is more power-per-pound of battery.

Our AGM topping process assures that the maximum retainable electrolyte quantity is held within the battery separators, without leaving any unabsorbed liquid to spill or leak.

Tank Formed Plates

East Penn is the only battery manufacturer that uses tank formation to activate the battery plates. This process guarantees a fully formed and voltage matched plate. The extra handling of the plates provides an additional inspection step in the process to verify plate quality. Ultrapremium, Gel Glass Mat, Double Insulating Separators Another critical component is the separator, which isolates the positive from the negative plate. The separator must allow maximum charge flow between the plates for maximum performance. Separator failure is a leading cause of warranty claims
and customer dissatisfaction. East Penn uses an ultrapremium grade separator in our gel batteries. We believe that this expense (which is 5 to 6 times higher than other types) is worth the benefits of extended life and performance:

* The fiberglass mats embed themselves into the surface of the plates, acting like reinforcing rods in concrete. This
extra reinforcement locks the active material onto the plate for longer life and extended performance.
* The ultra-clean separators have no oil contamination or other impurities. Therefore, resistance is low and
battery performance is high.
* Excellent porosity allows maximum charge flow, which means more power-per-pound.
* Superior resistance to oxidation dramatically reduces separator failure, which extends life.
* Our separators are especially suited for gel batteries, while others use separators designed for flooded
automotive batteries.

Ultrapremium AGM glass mat separators

Glass mat separator properties can vary considerably. East Penn uses glass mat engineered to have an ideal balance of properties¡ª i.e. absorbency, compressibility, puncture resistance and electrical resistance. This attention to detail results in high performance and long life.

Exclusive Thru-Partition Weld Seals

One of the causes of self-discharge in batteries is the minute electrical currents that flow between each cell through the partition at the weld area. These currents accelerate the discharge of batteries not in use.

We block these currents by using an exclusive weld seal or gasket.This feature dramatically reduces self-discharge to less than 3% per month: the lowest self-discharge rate of any battery manufacturer and seven times lower than many conventional batteries!

Exclusive Patented Calcium/Copper Lead Alloy Grids

This exclusive alloy provides longer shelf life, more powerper-pound and superior corrosion resistance. By using special
grain refiners, we can dramatically improve performance and life.

Heavy-Duty Motive Power Style Grid Design

While other manufacturers cut costs by using automotive style grids, we use a high-performance deep cycle grid. This heavy-duty grid design is similar to the grid in a motive power battery. The hefty ¡°power rods¡± designed into our grids not only lock the active material onto the grid, but also act as ¡°bus bars¡± to collect and direct the energy to the terminals. The benefit is more powerper- pound of battery for your equipment and longer battery life.

Multiple Plate Lug Milling

Shiny, well milled plate lugs are critical to our superior cast-on-strap quality. Each of our plate lugs is automatically milled to assure the highest quality strap with no loose or dropped plates. Our lugs are then fluxed and tinned automatically for an additional assurance of quality.

Heavier Plate Straps

We use an exclusive lead/tin alloy in a unique multi-stage caston- strap operation. The result is heavier straps with outstanding lug-to-strap knit. This eliminates dropped and loose plates, thereby improving performance and life.
Polyester Element Wrap Another cause of deep-cycle battery failure is ¡°mossing.¡± This phenomenon occurs late in a battery¡¯s life, as the positiveactive material actually grows around the edge of the separatorand eventually ¡°shorts¡± against the negative plate. This ends the battery¡¯s service life.Our AGM separators wrap around the bottom of the plate and are wider than the plates. This makes mossing failures unlikely. To prevent life-shortening mossing in our gel batteries, we use a special polyester fiber sheet that is wrapped around the edge of each element, similar to the wrap in an industrial battery. The result is longer service life.

Exclusive Forged Posts and Bushings

¡°Black¡± posts and oxygen-contaminated batteries are often due to porous lead terminal posts. A battery can lose its critical pressure through tiny pores and fissures in the battery terminals. Pressure loss is harmful to the battery and is evident by black posts, which are caused by sulfuric acid fumes escaping from the battery through and around the lead posts and bushings. These fumes can cause corrosion and can damage sensitive electronic equipment. These pores and fissures are caused by the industry¡¯s method of casting posts and bushings. This method produces tiny air pockets
and paths which allow corrosive gas to escape, causing life shortening depressurization, cell dry-out and corrosion damage.
To eliminate this problem, we use forged terminal posts and bushings, which are completely solid with absolutely no porosity. The benefit is longer life, better performance and no leakage of corrosive gas¡­especially important when installed in or near sensitive electronic equipment.

Acid Stratification Prevention

Acid stratification can occur in conventional wet cells. During charge, acid is released at the plate surfaces. During discharge, acid is consumed at the plate surfaces. Since the concentration is not uniform, diffusion (spontaneous mixing by random molecular motions) begins. If this mixing occurred rapidly, stratification would not occur, but it is relatively slow, allowing lighter parts of electrolyte to ¡°float¡± toward the surface and heavier parts to ¡°sink¡±toward the bottom.
The top portion of the plates do not perform as well in contact withlower concentration electrolyte. The bottom portion of the plates do not perform as well with the higher concentration, and will corrode prematurely. High voltage ¡°equalization¡± charging is sometimes used in wet batteries to make gas bubbles that re-mix the electrolyte.Because the immobilized gel will not ¡°float¡± or ¡°sink¡± within itself when a non-uniform concentration exists, it cannot stratify. Therefore, no high-voltage equalizing charge is necessary. Simply recharge at the standard 13.8 to 14.1 voltage setting. This means longer life and consistent performance in stationary and standby applications.

Electrolyte in an AGM battery is strongly held by the capillary forces between the glass mat fibers, but not completely
immobilized. Stratification is possible in extremely tall cells, but cannot occur in batteries of the size covered in this document.

Convenient Carrying Handles

This feature makes carrying, installation and removal easier, more convenient and less time consuming.

Dozens of Terminal Options Available

Our batteries are delivered with the most popular type of terminal; however, on a special order basis many terminal options are available. This gives you total flexibility to specify the proper terminal for your application¡­ without making compromises.

Proprietary Case, Cover, and Pressure Vent

We design and mold our own rugged polypropylene cases, vents and covers in our on-site, state-of the-art plastics molding facility. This provides ultimate control of our high performance designs, quality and delivery to our manufacturing plant, assuring you the highest quality battery and most reliable service.

Environment and Worker Protection

It¡¯s nice to know that every possible safeguard was designed into our process to protect our co-workers and the environment¡­ special safeguards that are exclusive to East Penn. One benefit is assurance of a consistent source for batteries without fear of governmental interference or delays.

Over 250 Quality Assurance Checks

Hundreds of quality checks are performed to assure total confidence in the performance and life of our batteries.
For example:
* 100% Cycling. After initial charging, every battery is discharged and then recharged at the factory. This allows us to check the performance of the battery and give it a second charge that equalizes the cells for improved performance and longer life.
It¡¯s interesting to note that, as a cost-saving measure, we use the current generated during the initial discharge to recharge other batteries in this computer-controlled process.
* Extended Shelf Stand Test. Before shipment, every battery is required to stand for a designated period of time.
Beginning and ending voltages are compared. This extra quality assurance step verifies that the critical pressure
control valves are functioning properly.
* Filling Weight Control. During this computerized process, batteries are weighed before and after filling. This assures
that the exact amount of electrolyte is in each battery.
* Multi-Staged Filling and Vacuuming Process. Every battery is filled and vacuumed several times during
this computerized process. Multi-staged vacuuming assures complete electrolyte-to-plate interface, with no
power-robbing air pockets.
* Computerized Polarity Check. Every battery is checked by computer for proper polarity.
* High Rate Discharge Test. Every battery is discharged at approximately twice the rated capacity. A sensitive computer
monitors the voltage drop during this discharge to assure that every battery performs as designed.
* Formed Element Inspection. Elements are assembled and charged outside the battery container in a computerized
forming and drying process. This allows visual inspection of every grid, plate, separator, and formed element before being
sealed inside the battery, assuring perfect cell elements with longest life and highest performance.
* Tank Formed Plates. Voltage matched plates are critical in standby applications. Forming each plate outside the battery assures the highest quality, best matched plates in the industry, and also allows a visual check before and during assembly.

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