Guide to VRLA Batteries

2
II. AGM & GEL BATTERIES
VRLA technology encompasses both gelled electrolyte or gel
batteries and absorbed glass mat or AGM batteries. Both types
a
re regulated by special one-way, pressure-relief valves and
have significant advantages over flooded lead-acid products.
AGM (Absorbed Glass Mat) batteries
T
he electrolyte in AGM batteries is completely absorbed in
separators consisting of matted glass fibers. This causes them
to be spillproof, meaning they don’t leak acid like a flooded
design if tipped on their side. The glass mats in AGM batteries
are wrapped around the positive plate, which helps prevent
damage from vibration and extend cycling. The battery’s
groups are packed tightly in the case partitions also protect-
ing its power producing components. AGM battery designs
can have over twice the cycle life of a conventional flooded
product in the right application.
Gel or Gelled Electrolyte batteries
The electrolyte in a Gel battery is permanently locked in a
highly viscous gelled state instead of the traditional liquid
form. Because there is no liquid-type electrolyte, it will not
leak out of the battery if tipped on its side. The thick, gelled
electrolyte and tightly packed groups also protect the bat-
tery’s power producing components. Gel battery designs
have a superior deep discharge resiliency and can deliver
over two to three times the cycle life of an AGM product in
the right applications.
Similarities between Gel
and AGM VRLA technology
n
Batteries utilize special one-way, pressure-relief valves
and must never be opened.
n
Requires no electrolyte maintenance unlike deep cycle
flooded batteries that require frequent checking and
adjustment of electrolyte levels.
n
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).
n
Spillproof design enables installation in virtually any
position (upside-down installation is not recommended).
n
Has a higher tolerance against damage from deep
discharge. These batteries have optimized amounts of
electrolyte (which is also referred to as “acid-starved”) so
that they use the power in the acid before they use the
power in the plates. This minimizes the destructive nature
of ultra-deep discharges. Ultra-deep discharging is what
causes plate shedding, which can destroy a battery.
Major difference between Gel
and AGM battery performance
A Gel battery is better suited for super-deep discharge appli-
cations, which means it can withstand deeper discharges
without damaging the battery’s performance. However, due to
the physical properties of the gelled electrolyte, Gel battery
power declines faster than an AGM battery as the temperature
drops below 32ºF (0ºC). AGM batteries excel for high current,
high power applications and in extremely cold environments.
AGM batteries deliver a better dual purpose solution for a
combination of starting and accessory power.
Advantages of GEL and AGM battery designs
KEY BATTERY BENEFITS GEL AGM
Premium maintenance-free design Yes Yes
A
ir transportable
Yes Yes
(most sizes) (many sizes)
Spillproof construction,
won’t leak if turned sideways
Yes Yes
Minimizes terminal corrosion Yes Yes
Superior deep cycle life and resiliency Yes Yes
to deep discharge damage (Best) (Good)
Operates at severe angle or on side
(won’t leak or spill)
Yes Yes
Low to no gassing Yes Yes
Ideal for use around sensitive
Yes Yes
electronic equipment
Extended shelf life,
Yes Yes
low self-discharge rate
Enhanced recharging efficiency Yes Yes
Resistance to vibration Yes Yes
Delivers the best combination starting, Yes Yes
cycling, and deep cycle service (Good) (Best)
Operation in cold temperatures
Yes Yes
(Good) (Best)
Cold engine cranking Low Yes
III. EAST PENN’S AGM & GEL VRLA
BATTERY DESIGN
Features and benefits that make our
VRLA batteries unique
East Penn Expertise
East Penn builds VRLA batteries to the highest standards.
Our manu facturing process features improved controls
using state-of-the-art computers and the latest manufacturing
technology and equipment. VRLA batteries produced by East
Penn consistently meet the highest quality performance and
life standards.
One-Way, Pressure-Relief Valves
A critical feature of any VRLA battery is the quality of the seal-
ing valve. Not only must the valve safely release excessive
pressure and gas, but it must also keep the cell from being
contaminated by the atmosphere. Oxygen contamination will
discharge and eventually ruin a VRLA battery. Our valves
are UL recognized and 100% tested. The benefit is reliable
performance and long life.