Guide to VRLA Batteries

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Proprietary Case, Cover, and One-Way,
Pressure-Relief Valve
We design our own highly functional polypropylene cases,
valves, and covers. Many are molded 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.
East Penn’s Quality Assurance Checks
Below are a few examples of the hundreds of quality checks
that are performed on Gel or AGM battery types to assure total
confidence in the performance and life of our batteries:
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Extended Shelf Stand Test. Before shipment, every battery
is required to stand for a period of time and ending volt-
ages are analyzed. This extra quality assurance step verifies
that the batteries are optimized for electrical performance.
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Computer-Enhanced Filling Controls. During this com-
puterized process, batteries are monitored and filled to
exacting levels for precision separator absorption and
complete permeation.
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Multi-Staged Filling and Vacuuming Process. Every bat-
tery is filled and vacuumed several times during this
computerized process. Multi-staged vacuuming assures
complete electrolyte-to-plate interface.
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Computerized Polarity Check. Every battery is checked by
computer analysis for proper polarity.
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Discharge Test. High-precision calibrated sensors allow
computers to monitor the voltage drop during this dis-
charge to assure that every battery performs as designed.
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Grid Casting Inspections. Specified checks such as alloy
sampling, lead pot temperatures, ladle temperatures, grid
weight and thickness analysis assures patented alloy blend
and precise conditions for proper grid formation and appli-
cation into battery production.
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Acid Mixing Checks. Regulatory acid temperature
and specific gravity monitoring optimizes battery
performance and longevity.
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Paste Mixing Monitoring. Computer-assisted formula
monitoring and extensive acid gravity and temperature
checks provide best attributes for paste adhesion, power
absorption and delivery performance.
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Paste-to-Grid Application Monitoring. Temperature,
thickness, weight and line speed analysis assures proper
adhesion and extended service life.
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Curing Checks. Assures proper time, temperature, and
humidity to create the optimal environment to facilitate the
c
uring process.
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Cast-On-Strap and Assembly Audits. Monitors lead
temperatures, line speed, alloy sampling, weld quality,
terminal burn depth, and leak testing all to ensure the
final assembled product meets rigid specifications and
standards providing a solid construction to support
premium VRLA battery products.
IV. GENERAL QUESTIONS
ABOUT VRLA BATTERIES
What do I need to know about
VRLA battery charging?
All lead-acid batteries release hydrogen from the negative
plate and oxygen from the positive plate during charging.
VRLA batteries have one-way, pressure-relief valves.
Without the ability to retain pressure within the cells, hydro-
gen and oxygen would be lost to the atmosphere, eventually
drying out the electrolyte and separators.
Voltage is electrical pressure (energy per unit of charge).
Charge (ampere-hours) is a quantity of electricity. Current
(amperes) is electrical flow (charging speed). A battery can
only store a certain quantity of electricity. The closer it gets
to being fully charged, the slower it must be charged.
Temperature also affects charging. If the right voltage is used
for the temperature, a battery will accept charge at its ideal
rate. If too much voltage is used, charge will be forced
through the battery faster than it can be stored.
Reactions other than the charging reaction also occur to
transport this current through the battery—mainly gassing.
Hydrogen and oxygen may be given off faster than the
recombination reaction. This raises the pressure until the
one-way, pressure-relief valve opens. The gas lost cannot
be replaced. Any VRLA battery will dry out and fail prema-
turely if it experiences excessive overcharging.
Note: It is too much voltage that initiates this problem, not too
much charge — a battery can be “over-charged” (damaged
by too much voltage) even though it is not fully “charged.”
Never install any lead-acid battery in a sealed container
or enclosure. Hydrogen gas must be allowed to escape.
Can continual undercharging
harm a VRLA battery?
In many respects, undercharging is as harmful as over-
charging. Keeping a battery in an undercharged condition
allows the positive grids to corrode and the plates to
shed, dramatically shortening life. Also, an undercharged
battery must work harder than a fully charged battery,
which contributes to short life as well.
An undercharged battery has a greatly reduced capacity. It
may easily be inadvertently over-discharged and eventually
damaged.
Do VRLA batteries have a “memory”
like Ni-Cad batteries?