11
Valve Regulated (Sealed) Lead-Acid Batteries
Overview
OVERVIEW
Panasonic Valve Regulated (Sealed) lead-acid
battery (VRLA battery) have been on the market for
more than 30 years. The VRLA battery is a recharge-
able battery which requires no watering.
Adopting lead-tin-calcium alloy as the grid alloy, it has
outstanding characteristics against severe use
conditions such as overcharge, overdischarge,
vibration, shock and also for various storage condi-
tions. Our accumulation of technologies has enabled
us to respond to market requirements promptly by
developing batteries such as trickle/cycle long life
type .
The VRLA battery covers a broad range of
applications including, electric tools, UPS, and three
and four wheel electric wheel chairs for the elderly.
Battery types and model numbers
For main power source
For main and standby
power source
For standby power source
Cycle long life type .....................LC-XC
Expected trickle life 3-5(* 6) years..LC-R
Standard case .............LC-X
Flame-retardant case ..LC-P
Expected trickle life: Up to 50% of initial capacity under the following conditions:
Temperature: 25˚C
Discharge current: 0.25CA
Discharge ending voltage: 5.25V for 6V battery, 10.5V for 12V battery
Charge voltage: 6.85V for 6V battery, 13.7V for 12V battery
*Life : conform to Eurobat ( 20˚C / 0.1C)
Expected trickle life 3-5 (* 6) years...UP-RW
Expected trickle life approx. 6(*10) years
12
Valve Regulated (Sealed) Lead-Acid Batteries
GENERAL INFORMATION ON VALVE REGULATED (SEALED) LEAD-ACID BATTERIES
Construction and Electrolyte
Electrochemical Reactions on Electrodes
Positive plates
Positive plates are plate electrodes of which a grid
frame of lead-tin-calcium alloy holds porous lead
dioxide as the active material.
Negative plates
Negative plates are plate electrodes of which a grid
frame of lead-tin-calcium alloy holds spongy lead as
the active material.
Electrolyte
Diluted sulfuric acid is used as the medium for
conducting ions in the electrochemical reaction in the
battery.
Separators
Separators, which retain electrolyte and prevent
shorting between positive and negative plates, adopt
a non-woven fabric of fine glass fibers which is
chemically stable in the diluted sulfuric acid electro-
lyte. Being highly porous, separators retain electro-
lyte for the reaction of active materials in the plates.
Valve (One way valve)
The valve is comprised of a one-way valve made of
material such as neoprene. When gas is generated
in the battery under extreme overcharge condition
due to erroneous charging, charger malfunctions or
other abnormalities, the vent valve opens to release
excessive pressure in the battery and maintain the
gas pressure within specific range (7.1 to 43.6 kPa).
During ordinary use of the battery, the vent valve is
closed to shut out outside air and prevent oxygen in
the air from reacting with the active material in the
negative electrodes.
Positive and negative electrode terminals
Positive and negative electrode terminals may be
faston tab type, bolt fastening type, threaded post
type, or lead wire type, depending on the type of the
battery. Sealing of the terminal is achieved by a
structure which secures long adhesive-embedded
paths and by the adoption of strong epoxy adhesives.
For specific dimensions and shapes of terminals, see
page 68.
Battery case materials
Materials of the body and cover of the battery case
are ABS resins, unless otherwise specified.
The electrochemical reaction processes of the
sealed lead-acid battery (negative electrode
recombination type) are described below.
Where “charge” is the operation of supplying the
rechargeable battery with direct current from an
external power source to change the active material
Example of construction
Connector
Separator
Valve
(-) Negative terminal
Positive
electrode pole
Negative
electrode pole
Positive plates
Negative plate
(+) Positive terminal
Top cover
Cover
Battery case
in the negative plates chemically, and hence to store
in the battery electric energy in the form of chemical
energy. “Discharge” is the operation of drawing out
electric energy from the battery to operate external
equipment.
(
Positive electrode) (Negative electrode) (Electrolyte)
Discharge
Charge
(Lead dioxide) (Lead) (Sulfuric acid) (Lead sulfate) (Water)(Lead sulfate)
(Positive electrode) (Negative electrode) (Electrolyte)
Pb 2H O
2
PbSO
4
PbSO
4
PbO
2
2H SO
242
++++
13
Valve Regulated (Sealed) Lead-Acid Batteries
GENERAL INFORMATION ON VALVE REGULATED (SEALED) LEAD-ACID BATTERIES - CONTINUED
In the final stage of charging, an oxygen-generating
reaction occurs at the positive plates. This oxygen
transfers inside the battery, then is absorbed into the
surface of the negative plates and consumed. These
electrochemical reaction processes are expressed as
follows.
Applications
Stand-by/Back-up power applications
¾Communication equipment: base station,
PBX, CATV, WLL, ONU, STB, etc.
¾Back-up for power failure: UPS, ECR, com-
puter system back-up, sequencers, etc.
¾Emergency equipment: lights, fire and burglar
alarms, radios, fire shutters, stop-position
controls (for machines and elevators), etc.
Main power applications
¾Communication and telephone equipment:
cellular phones (bag phones), transceivers,
etc.
¾Electrically operated vehicles: picking carts,
automated transports, electric wheelchairs,
cleaning robots, electric automobiles, etc.
¾Tools and engine starters: grass shears,
hedge trimmers, cordless drills, screwdrivers,
jet-skis, electric saws, etc.
¾Industrial equipment/instruments and non life-
critical medical equipment*: measuring equip-
ment, non life-critical medical equipment
(electrocardio-graph), etc.
¾Photography: camera strobes, VTR/VCR,
movie lights, etc.
¾Toys and hobby: radio-controllers, motor
drives, lights, etc.
¾Miscellaneous uses: integrated VTR/VCR,
tape recorders, other portable equipment, etc.
*(Note) When any medical equipment incorporating a Panasonic VRLA
battery is planned, please contact Panasonic.
Features
Leak-resistant structure
A required-minimum quantity of electrolyte is impreg-
nated into, and retained by, the positive and negative
plates and the separators; therefore electrolyte does
not flow freely. Also, the terminal has a sealed struc-
ture secured by long adhesive-embedded paths and
by the adoption of strong epoxy adhesives which
makes the battery leak-resistant. (Note) In stand-by/
back-up uses, if the battery continues to be used
beyond the point where discharge duration has
decreased to 50% of the
initial (i.e. life judgment criteria), cracking of the
battery case may occur, resulting in leakage of the
electrolyte.
Long service life
Service life of our long-life series (LC-P, LC-X series
is approximately double that of the conventional (LC-
R) batteries (Temperature 25°C, discharge rate 0.25
CA/ 1.75V/cell, discharge frequency every 6 months,
2.30V/cell charge).
Easy maintenance
Unlike the conventional batteries in which electrolyte
can flow freely, VRLA batteries do not need the
specific-gravity check of the electrolyte nor the
watering structurally; this makes the battery function
fully and makes maintenance easy.
No sulfuric acid mist or gases
Unlike the conventional batteries in which electrolyte
can flow freely, VRLA batteries generate no sulfuric
acid mist or gases under the use condition we
recommend. In uses under conditions other than
recommended, however, gas generation may occur,
therefore do not design the battery housing with a
closed structure.
Exceptional deep discharge recovery
As seen in the figure on the next page, our VRLA
battery shows exceptional rechargeablity even after
deep discharge, which is often caused by failure to
turn off the equipment switch, followed by standing
(approx. 1 month at room temperature is assumed).
(Positive electrode)
(Negative electrode) Charge (Lead dioxide)
(Lead sulfate)
(Lead sulfate)
O
2
PbSO
4
PbSO
4
Gas recombination reaction cycle
Charge Overcharge
(Oxygen)
(Lead)
Reaction
2
PbO
2
Pb(O )
14
Valve Regulated (Sealed) Lead-Acid Batteries
GENERAL INFORMATION ON VALVE REGULATED (SEALED) LEAD-ACID BATTERIES - CONTINUED
Transportation
Our VRLA batteries should be handled as common
cargo for both air shipment (*1) and boat shipment
(*2), as they can withstand electrolyte leakage during
the vibration test, the differential atmospheric pres-
sure test and the altitude test in accordance with the
special requirements of transportation regulations
specified by the international organizations (ICAO:
International Commercial Aviation Organization and
IMO: International Maritime Organization).
(*1: Special provision A67 *2: Special provision 238)
ISO
The Quality System and the Environmental Manage-
ment System at our palants were recognized and
registered as conforming to ISO.
ISO 9001:2000
ISO 9002 ISO 14001
MBI-SBD 
(Japan)
SLMB 
JIS (Japan Industrial Standards)
Our small sized VRLA batteries comply with JIS C
8702.
Example of rechargability after deep discharge
and standing
UL recognition
Our VRLA batteries fall into UL1989 (Standby Batter-
ies). UL1989 requires that the battery is free from the
hazard of bursting, that is, when the battery is over-
charged the vent valve opens to release internal
pressure. UL-recognized types of VRLA batteries to
date are listed in the following table. A number of the
recognized battery types are in use for such applica-
tions as emergency lights.
VdS and other recognition
The types of VRLA batteries which have acquired
VdS (Germany) recognition and the Japanese rec-
ognition to date are also listed.
Table of battery types which acquired local/
overseas recognition
Additional configuration codes (alphabetic letters or numbers) may appear for (a) in the code numbers of UL recognized types.
(Note) These standards are also valid for old model numbers.
Charge time (hours)
Current (A)
2.0
1.6
1.2
0.8
0.4
0.0048121620
Current product
LC-064R2P Conventional type
(6V4Ah)(6V4.2Ah)
(Test condition)
Discharge: 24 hours at 6 ohms
Hold: Standing for 1 month in
open-circuit state
Charge: 6.9V constant-voltage
charging for 16 hours;
Maximum current: 1.6V
Temperature: 25˚C
noitingocer/dradnatS stnetnoC rebmunnoitingoceR sledoMdezingoceR
LU
dradnatsytefaS.S.U
9891LU
seirettaBybdnatS 32731HM
ytefaSnamreGSdV
dradnatS
UP-RW1220(a)
UP-RWA1232(a)
UP-RW1245(a)
LC-R061R3(a)
LC-R063R4(a)
LC-R064R2(a)
LC-R067R2(a)
LC-R0612(a)
LC-R121R3(a)
LC-R122R2(a)
LC-R123R4(a)
LC-R127R2(a)
LC-RA1212(a)
LC-RD1217(a)
LC-R1233(a)
LC-V1233(a)
LC-P067R2(a)
LC-P0612(a)
LC-P127R2(a)
LC-PD1217(a)
LC-X1220(a)
LC-X1224(a)
LC-X1228(a)
LC-X1238(a)
LC-X1242(a)
LC-X1265(a)
LC-XA12100(a)
LC-XC1228(a)
LC-XC1238(a)
G196049
G193046
G198049
G199090
G188151
G100001
G100002
G191053 LC-R121R3PG
LC-R127R2PG/PG1
LC-X1224APG/AP
LC-X1265PG/P
LC-R122R2PG
LC-RA1212PG/PG1
LC-X1238APG/AP
LC-R123R4PG
LC-RA1212P/P1
LC-X1238PG/P
(China)
25$5
25$
15
Valve Regulated (Sealed) Lead-Acid Batteries
CHARACTERISTICS
Charging
Charge characteristics (constant voltage-constant
current charging) of VRLA batteries are exemplified
below.
Example of constant-voltage charge characteris-
tics by current
In order to fully utilize the characteristics of VRLA
batteries, constant-voltage charging is recom-
mended. For details of charging see page 19.
Discharging
a) Discharge current and discharge cut-off
voltage
Recommended cut-off voltages for 6V and 12V
batteries consistent with discharge rates are given in
the figure below. With smaller discharge currents, the
active materials in the battery work effectively, there-
fore discharge cut-off voltages are set to the higher
side for controlling overdischarge. For larger dis-
charge currents, on the contrary, cut-off voltages are
set to the lower side.
(Note) Discharge cut-off voltages given are recom-
mended values.
Discharge current vs. Cut-off voltage
b) Discharge temperature
(1) Control the ambient temperature during dis-
charge within the range from -15°C to 50°C for the
reason described below.
(2) Batteries operate on electrochemical reaction
which converts chemical energy to electric energy.
The electrochemical reaction is reduced as the
temperature lowers, thus, available discharge capac-
ity is greatly reduced at temperatures as low as -
15°C. For the high temperature side, on the other
hand, the discharge temperature should not exceed
50°C in order to prevent deformation of resin materi-
als which house the battery or deterioration of ser-
vice life.
c) Effect of temperature on discharge character-
istics
Available discharge capacity of the battery varies
with ambient temperature and discharge current as
shown in the figure below.
Discharge capacity by temperature and by dis-
charge current
(Test condition)
Discharge : 0.05 CA constant-
current discharge
Cut-off voltage; 1.75 V/cell
Charge : 2.45 V/cell
2.30 V/cell
Temperature : 25˚C
0 3 6 9 12 15 18
2.5
2.0
0.4
0.3
0.2
0.1
0
Current Voltage
Charge time (hours)
(CA)
(V/cell)
~
~~
~
120
100
80
60
40
20
0
-20 -10 0 10 20 30 40 50
Capacity (%)
Temperature <˚C>
0.05CA
0.1CA
0.25CA
1CA
Discharge current (CA)
Discharge cut-off voltage (12V battery)
Discharge cut-off voltage (6V battery)
5.4
5.2
5.0
4.8
4.6
4.4
4.2
4.0
10.8
10.4
10.0
9.6
9.2
8.8
8.4
8.0
0.05 0.1 0.2 0.3 0.5 1 2 3
16
Valve Regulated (Sealed) Lead-Acid Batteries
CHARACTERISTICS - CONTINUED
d) Discharge current
Discharge capability of batteries is expressed by the
20 hour rate (rated capacity). Select the battery for
specific equipment so that the discharge current
during use of the equipment falls within the range
between 1/20 of the 20 hour rate value and 3 times
that (1/20 CA to 3 CA): discharging beyond this
range may result in a marked decrease of discharge
capacity or reduction in the number of times of
repeatable discharge. When discharging the battery
beyond said range, please consult Panasonic in
advance.
e) Depth of discharge
Depth of discharge is the state of discharge of
batteries expressed by the ratio of amount of capac-
ity discharged to the rated capacity.
Storage
a) Storage condition
Observe the following condition when the battery
needs to be stored.
(1) Ambient temperature: -15°C to 40°C (preferably
below 30°C)
(2) Relative humidity: 25% to 85%
(3) Storage place free from vibration, dust, direct
sunlight, and moisture.
b) Self discharge and refresh charge
During storage, batteries gradually lose their capacity
due to self discharge, therefore the capacity after
storage is lower than the initial capacity. For the
recovery of capacity, repeat charge/discharge sev-
eral times for the battery in cycle use; for the battery
in trickle use, continue charging the battery as loaded
in the equipment for 48 to 72 hours.
c) Refresh charge (Auxiliary charge)
c) Refresh charge (Auxiliary charge)
When it is unavoidable to store the battery for 3
months or longer, periodically recharge the battery at
the intervals recommended in the table below de-
pending on ambient temperature. Avoid storing the
battery for more than 12 months.
d) Residual capacity after storage
The result of testing the residual capacity of the
battery which, after fully charged, has been left
standing in the open- circuit state for a specific period
at a specific ambient temperature is shown in the
figure below. The self discharge rate is very much
dependent on the ambient temperature of storage.
The higher the ambient temperature, the less the
residual capacity after storage for a specific period.
Self discharge rate almost doubles by each 10°C rise
of storage temperature.
Residual capacity test result
30˚C 25˚C
0 3 6 9 12 15
Storage period (months)
100
80
60
50
40
20
0
Residual capacity
40˚C
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)egrahchserfer(egrahc
C°02woleBshtnom9
C°03otC°02shtnom6
C°04otC°03shtnom3
17
Valve Regulated (Sealed) Lead-Acid Batteries
CHARACTERISTICS - CONTINUED
e) Open circuit voltage vs. residual capacity
Residual capacity of the battery can be roughly
estimated by measuring the open circuit voltage as
shown in the Figure.
Open circuit voltage vs. Residual capacity 25°C
Temperature conditions
Recommended temperature ranges for charging,
discharging and storing the battery are tabulated
below.
Battery life
a) Cycle life
The cycle life (number of cycles) of the battery is
affected by such factors as battery types, charging
methods, ambient temperature, interval between
charge and discharge, or depth of discharge. Typical
cycle life characteristics of the battery are shown in
the above figure. This is typical data obtain from a
well-equipped laboratory.
Cycle times depend on each model of batteries and
may differ from this data when batteries are actully
used in the field.
Expected life is also affected by charge conditions.
For life performance, please check actual charge/
discharge pattern in the field. The life is shortened at
shallow discharge about less than 30% of rated
capacity. For additional inquiries, please contact
Panasonic office.
Cycle life characteristics
(Temperature: 25˚C)
7.00
6.75
6.50
6.25
6.00
5.75
5.50
5.25
5.00
14.0
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0
0 20 40 60 80 100
Residual capacity (%)
Open circuit voltage (6V battery)
Open circuit voltage (12V battery)
egrahC C°04~C°0
egrahcsiD C°05~C°51-
egarotS C°04~C°51-
00 100 200 300 400 500 600
20
40
60
80
100
120
Capacity (%)
Charge/discharge cycle (number of cycles)
(Test condition)
Discharge : 0.25CA
Cut-off voltage 1.75V/cell
Charge : 2.45 V/cell constant-voltage control
Maximum current: 0.4 CA
12 hours
Temperature : 25˚C
18
Valve Regulated (Sealed) Lead-Acid Batteries
CHARACTERISTICS - CONTINUED
b) Trickle (Float) life
Trickle life of the battery is largely dependent on the
temperature condition of the equipment in which the
battery is used, and also related to the type of the
battery, charge voltage and discharge current. The
respective Figures show the influence of temperature
on trickle life of the battery, an example of trickle
(float) life characteristics of the battery, and the test
result of the battery life in an emergency lamp.
Influence of Temperature on Trickle life
Trickle life characteristics at 50°C
Testing conditions
Discharge: 0.25 CA, End voltage: 1.7V/2V
Charging: 2.275V/2V, Constant-voltage control,
current: 0.15 CA
Conventional products
Trickle long life series
10 20 30 40 50 60 70
Temperature <˚C>
Service life (years)
15
10
5
3
1
0.5
0.1
(Test condition)
Discharge : 0.25 CA
Cut-off voltage : 1.75V/cell
Capacity check by every 3 months
Charge : 2.30V/cell
Constant-voltage control
Maximum current : 0.4 CA
Temperature : 20˚C to 23˚C
Time (years)
Capacity (%)
120
100
80
60
40
20
0 1 2 3 4
(Test condition)
Discharge : 0.25 CA
Cut-off voltage: 1.7V/2V
Charge : 2.275V/2V
Constant-voltage control 0.2 CA
Discharge frequency : once ever y 21 days
Trickle long
life series
Conventional
products
0 2 4 6 8 10 12 14 16
50˚C discharge period (months)
Conversion to 25˚C period (years)
Duration of discharge (minutes)
300
250
200
150
100
50
0
0 1 2 3 4 5 6 7
Conversion to 20˚C period (cycles)
0 1 2 3 4 5
Trickle (Float) life characteristics (LC-R)