Main Application Medical equipment Fire & security systems Electronic cash registers Communication equipment Telecommunication systems Uninterruptible power supplies Power tools Solar powered systems Other standby or primary power supplies |
|---|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The VRLA battery uses an absorbed electrolyte system. All of the electrolyte is absorbed into the positive plates, negative
plates, and the separators, Coupled with the use of special sealing epoxies, and long sealing paths for posts, VRLA
battery have exceptional leak resistance, and can be used any position.
1.2 Sealed and Maintenance-free Operation There is no corrosive gas generation during normal use and no need to check the specific gravity of the electrolyte or to add water during the service life.
1.3 High Quality and High Reliability The VRLA battery has stable and reliable capacity. The battery can withstand overcharge, over discharge, vibration, and shock. To assure this high quality and reliability, the batteries are 100% tested on production line for voltage, capacity, seals and the safety valve are 100% visually inspected before the final assembly process.
1.4 Exceptional Deep Discharge Recovery Batteries have exceptional deep discharge recovery and charge acceptance, even after deep or prolonged discharge.
1.5 Low Self-discharge Because of the use of lead calcium grids alloy and highly purity materials. VRLA battery can be stored long periods of time without recharge. The rate of VRLA batter self-discharge on open circuit is less than 2% per month at 20
1.6 Long Service Life The VRLA battery has long life in standby or cyclic service.
1.7 Solid Copper Termials Ensures highest current carrying capability.
1.8 Tank-formed Plates The initial capacity will be 100% and optimize cell voltage balance, due to the tank formation of the plates.
1.9 Computer-aided Design and Manufacturing Ensures quality products through control of processes and standards.
2 Discharging
2.1 Final Discharging Voltage The final discharging voltage is the battery terminal voltage in close circuit voltage per cell to which a battery discharging safely and maximize battery life. The higher discharging current, the lower final discharging voltage of battery .
2.2 Battery Discharging Characteristics:
The discharging capacity of battery is depended on the discharge rate being used and ambient temperature. Figure 1 show the different discharging current corresponding discharging capacity at 25 . They show that the rated capacity of a battery is reduced when it is discharged at a value of current that exceeds its 10-hours or 20-hours rate.
3 Charging
3.1 Constant Voltage Charging
This is the recommended method of charging for VRLA batteries.
It is necessary to closely control the actual voltage to ensure that
it is with the limits advised.
Standby service: 2.23-2.30 vpc at 25
Cycle service: 2.40-2.50 vpc at 25
3.1 Charging Methods
Correct charging is one of the most important factor to conside
when using valve regulated lead acid batteries. Battery
performance and service life will be directly affected by the
charging methods.There are four major methods of charging.
Constant voltage charging.
Constant current charging.
Two stage constant voltage charging.
Taper current charging.
3.2 Constant Voltage Charging
This is the recommended method of charging for VRLA batteries.
It is necessary to closely control the actual voltage to ensure that
it is with the limits advised.
Standby service: 2.23-2.30 vpc at 25
Cycle service: 2.40-2.50 vpc at 25
It is suggested that the initial current be set within 0.4CAmps.
Figure 3 and 4 indicate the time taken to fully recharge the
battery. It is also seen that the charging current is decreased to
approx 0.5-4mA/Ah under charging voltage 2.30 vpc, and
3-10mA/Ah under charging voltage 2.40vpc when the battery is
fully charged at 25
Note: it is necessary to ensure that the voltage is correctly set.
The charging voltage set too high will increase the corrosion of
the positive plates causing loss of capacity and ultimately
shortening the life of the battery.
3.3 Constant Current Charging
This method of charging is generally not recommended for VRLA
batteries. It is necessary to understand that if the batteries are
not removed from the charger as soon as possible after reaching
a state of full charge. Considerable damage will occur to the
batteries due to over charging. The required recharged capacity
is 1.07 to 1.15 times discharged capacity
3.3.1 Two Stages Constant Voltage Charging
This method should not be used where the battery and load are
corrected in parallel, however, if this method is to be used, it is
suggested that the technical department is contacted.
3.3.2 Taper Current Charging
This method is not recommended for VRLA batteries, however,
if this method is to be used it is suggested that the First Power
technical department is contacted.
3.3.3 Effect of Temperature on Charging Voltage
As temperature rises, electrochemical activity in the battery
increases. Similarly, as temperature falls, electrochemical
activity decreases. Therefore, as temperature rises, charging
voltage should be reduced to prevent overcharge, as temperature
falls, charging voltage should be increased to avoid undercharge.
In general, to assure optimum service life, use of a temperature
compensated charger is recommended. The recommend
compensation factor for VRLA batteries is ±3mV
Cell (standby use) and±4mV cell(cyclic use). The standard
central point for temperature compensation is 20 . Figure 5
shows the relationship between temperatures and charging
voltages in both cyclic and standby applications.
3.4 Charging Time
The time required to complete each charge depends on the
discharge condition of battery, caracteristics of charge used,
or the temperature during charge. For cyclic use, using constant
voltage charging, this time can be estimated by the following
expression at 25 .
(1)Discharge current: Larger than 0.25CA
Tch =Cdis/i + 3 ~5
(2)Discharge current: Less than 0.25CA
Tch = Cdis/I+ 6 ~10
Tch: time required for charge (hours)
Cdis: ampere-hour discharged before charge started(Ah)
I : initial charging current(A).
Complete charge time for float service will be slightly more than
24 hours.
4 Battery Life
Battery life depends on a number of key factors. These include:
Operating temperature of the battery;
Method of charging utilized
4.1 Cyclic Life
Giving due consideration to the above factors, the actual life of a
battery in cycle service is dependent on the depth of discharge
of each cycle. The greater the depth of discharge of each cycle,
the lesser the number of cycles available from the battery.
4.2 Standby Life
The estimated life under float service of VRLA batteries is more
than 18 years at 20 . The float service life is effected by the
factors listed above and the number of discharging, the depth of
discharging the battery suffers during its life time. The more
discharges suffered and the deeper the discharges, the shorter the
battery life. The higher the temperature, the shorter the battery life.
If the battery temperature remains at an elevated level for an
extended period of time, the expected life is reduced by 50% for
each 8 to 10 of constant temperature above 20
Battery life depends on a number of key factors. These include:
Operating temperature of the battery;
Method of charging utilized;
4.1 Cyclic Life
Giving due consideration to the above factors, the actual life of a
battery in cycle service is dependent on the depth of discharge
of each cycle. The greater the depth of discharge of each cycle,
the lesser the number of cycles available from the battery.
