LAMAR CA-1550-CML User manual

Manual No LI-4159-CML Rev A
INSTRUCTION MANUAL
CA-1550 – CML
BATTERY CHARGER / ANALYZER
PLEASE NOTE: This Manual applies to Power Products Serial Numbers Q900 and higher,
and all Power Products by Lamar serial numbers.
Lamar Technologies LLC
14900 40th Ave NE
Marysville, WA 98271
Cage Code: 3RCD2
Ph: [phone] • Fax: [phone]
E-mail: [email protected]

TABLE OF CONTENTS
1
SYSTEM OVERVIEW ... ............................................................ .1
1.1 SYSTEM OVERVIEW.................................................................. .1
1.2 DISPLAYS AND CONTROLS...................................................... .2
2 INSTALLATION........................................................................ .3
2.1 LINE VOLTAGE ............................................................................. .3
2.2 TERMINALS ... ........................................................................... ...4
2.3 SPACE REQUIREMENTS......................................................... ...4
3 OPERATING GUIDE - CHARGING ... ................................... ...5
3.1 CHARGE CHARACTERISTICS ................................................. ...5
3.2 CHARGING METHODS ............................................................. ...6
3.3 PREPARATION FOR CHARGING ............................................... ..7
3.4 CHARGE TIME ............................................................................. ..9
3.5 SETTING CHARGE VOLTAGE AND CURRENT.......................... .9
4 OPERATING GUIDE - DISCHARGING ................................. .13
4.1 DISCHARGE CHARACTERISTICS ............................................ .13
4.2 DISCHARGE CAPACITY TESTING ... ......................................... .15
4.3 PREPARATION FOR TESTING ... ............................................... .16
4.4 DISCHARGE TIME .................................................................... ...18
4.5 CUTOFF VOLTAGE .................................................................. .18
4.6 SETTING DISCHARGE CURRENT ............................................ .21
4.7 TEST COMPLETION AND ANALYSIS...................................... ...22
5 CALIBRATION AND MAINTENANCE ... .............................. ...24
5.1 OVERVIEW OF CALIBRATION ................................................. .24
5.2 VOLTMETER CALIBRATION ...................................................... ..24
5.3 AMMETER CALIBRATION ........................................................ ...28
5.4 SHUNT VERIFICATION ............................................................ .31
5.5 DISCHARGE CURRENT OPERATING RANGE ....................... ...32
5.6
MAINTENANCE... .................................................................... ..32
6 TROUBLE-SHOOTING ......................................................... ..34
7 SPECIFICATIONS ................................................................... .36
WARRANTY ................................................................................. .37
CERTIFICATION OF CALIBRATION... ....................................... ..38

1. SYSTEM OVERVIEW
1 SYSTEM OVERVIEW
1.1 SYSTEM OVERVIEW
The CA-1550 Charger/Analyzer is a self-contained unit for charging and discharge
capacity testing of rechargeable batteries. It has been designed to accurately test,
charge and guarantee the emergency capacity of sealed or vented lead-acid or
nickel-cadmium batteries. Guaranteed emergency capacity is especially important for
aircraft batteries.
The unit comes in a convenient protective carrying case. It is very easy to move
around to accommodate flexibility in the work environment, whether used portable or
in the hangar or battery shop. The flexibility of charge and discharge parameters of
the CA-1550 makes it usable for a wide variety of batteries and voltages. The unit
accurately charges and tests lead-acid batteries of 12 or 24 volts, as well as nickel-
cadmium batteries of a single cell to 24 volts.
The charge unit of the CA-1550 allows charging at both constant potential and
constant current to give maximum flexibility in selection of charge method. The
charger has an adjustable charge current from 0 to 25 amperes, and an automatic
timer for charge time selection.
The discharge unit of the CA-1550 enables battery capacity testing with a constant
current of 0 to 50 amperes (usually set to 80-100% of the battery's capacity rating) for
a preset time. The unit automatically analyzes the discharge characteristics and
passes or fails the battery depending on the battery’s ability to maintain the
specified minimum voltage for the duration of the test.
1.2 DISPLAYS AND CONTROLS
The CA-1550 has been designed to have very simple and easy to understand
controls and displays.
Two digital panel meters allow viewing of charge and discharge current and
voltage. A digital electronic timer displays elapsed time and can be set to any fixed
duration period. Light indicators display if the unit is in charge or discharge mode and
also indicate battery pass or reject status after a discharge test (see Figure 1-
1).
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1. SYSTEM OVERVIEW
Figure 1-1. Controls and displays of CA-1550
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Meter Calibration
Test points
12 volt CP Adjust 24 Volt CP Adjust
Adjustment Tool
Timer
Voltmeter
Ammeter
Battery Voltage selector
Voltage cutoff adjuster
Voltage Cutoff View
Discharge Current Adjust
Charge/Discharge selector
Pass/Fail Indicators
Charge Current Adjust
Mains On/Off/Reset

2. INSTALLATION
2 INSTALLATION
2.1 LINE VOLTAGE
The CA-1550-CML can operate on either 115 or 230 volts AC. The desired line
voltage can be changed by opening the unit and modifying the voltage-set jumper(s).
The unit is factory-preset at 115 volts AC.
WARNING: Ensure that the unit is turned off and that no
battery is connected before attempting to open the cover.
CAUTION: Ensure that the unit is set for the appropriate
line voltage before operation.
A. Turn off the unit and remove any battery
B. Open the cover by first unscrewing the two screws on the far right of the
front cover.
C. Locate the four position terminal strip with jumper(s). Note: There is a red
stripe on top of each jumper in the photo below.
D. Two jumpers are used for 115VAC input and one jumper (across the middle
two screws) is used for 230VAC input. See Figures below.
Jumpers
115 volt AC setting 230 volt AC setting
E. For 230 VAC operation, the 115 VAC cord must be replaced with one for
230 VAC in required country configuration.
NOTE: If the plug has to be changed make sure to connect
the green AC line wire to ground.
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2. INSTALLATION
Connect the unit to a wall outlet with a 15-20 ampere capacity. Sharing of the line
with other equipment may result in erratic operation if other equipment draws high
pulse or surge currents.
NOTE: The CA-1550 will maintain its operational integrity
with line fluctuation up to ± 10%.
2.2 TERMINALS
Two important points about the DC battery cable and connector are:
A. If the aircraft battery quick disconnect connector is removed, the ring
terminals can be used to connect to a post terminal battery.
WARNING: Correct polarity must be observed.
B. If the cable is extended or repaired during maintenance, the sensing leads
which run with the heavy DC cable must be connected to the new terminal
(see section 5.6).
2.3 SPACE REQUIREMENTS
The CA-1550 system comes in a sturdy transit case. It occupies 17" x 20" (432 mm x
508 mm) of table top space and weighs about 55 pounds. Place the unit on a sturdy
workbench in a well-ventilated area with the battery adjacent to it.
The top of the unit has air flow from hot resistors. Always leave the cover open and
the resistor vent uncovered when in operation, to maintain proper air flow.
NOTE: In non air-conditioned rooms it is recommended
that circulating or extracting fans be used to aid in the
removal of heated air.
NOTE: Operation in dusty or otherwise dirty air
environments will severely reduce the cooling capacity of
the fans and can lead to premature failure.
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3. OPERATING GUIDE - CHARGING
3 OPERATING GUIDE - CHARGING
3.1 CHARGE CHARACTERISTICS
The constant current charge characteristics of a lead-acid cell with respect to cell
voltage, ampere-hours input, specific gravity and rate of gassing at constant
current can be seen in Figure 3-1.
Figure 3-1. Charge characteristics of a lead-acid cell
As shown by the curve in Figure 3-1 the cell voltage of a discharged battery rises
rapidly when the battery is first placed on charge. The extent of the initial rise
depends on the charging rate. As the charge continues, the voltage rises at a
slower rate and eventually levels off when a full state-of-charge is reached. It can
be seen that the specific gravity reading lags behind the rate of ampere-hour return
during most of the charging cycle. Consequently, the specific gravity is not
indicative of the available ampere-hour capacity until the cell approaches a full-
charge state.
When a battery reaches a full state-of-charge the voltage of the battery will
stabilize and remain constant or decrease. The charging should discontinue at this
stage. A minimum of 100% of previous discharged ampere-hours are required.
In general a vented battery may be charged at any rate that will not produce
excessive gassing or electrolyte temperatures above 115°F (46°C). Sealed lead-
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3. OPERATING GUIDE - CHARGING
acid batteries should never be charged in a constant-current mode with a current
greater than C /10 (C equals the rated ampere-hour capacity of the battery). During
constant current charging at a rate in excess of C /10, oxygen is produced at an
excessive rate. The resulting increasing pressure will cause the cell to vent. Venting
of gasses results in a depletion of electrolyte. As the electrolyte cannot be replaced in
a sealed battery, the cell will dry out resulting in a decrease in capacity and
eventually battery failure. Therefore constant-potential charging is the
recommended charge method for sealed batteries (SLAB).
3.2 CHARGING METHODS
There are two main methods of charging a battery: 1) constant current; and 2)
constant potential. In what follows both methods will be described in some detail.
3.2.1 CONSTANT-CURRENT CHARGE METHOD (CI)
In this method the current remains at a preset level while the voltage can reach a
high level, e.g. 34-37 volts.
An advantage of the constant-current charge method is that the ampere-hour input
into the battery can be determined precisely by multiplying the charging current
with the charge time in hours. However, it is necessary to ensure that the battery is
not charged at a high rate for an excessive period of time. Such overcharging can
result in overheating, excessive gassing, and possible damage to the battery.
3.2.2 CONSTANT-POTENTIAL CHARGE METHOD (CP)
A charge source applies a fixed (constant) voltage (potential) to the battery. The
current supplied by the charge source fluctuates (rises and falls) with the battery
voltage.
There are several advantages of the constant-potential charge method. First, there
is less danger of gassing at an excessive rate. Secondly, batteries of the same
nominal voltage but with different capacities can be connected in parallel directly to
the charging source. Thirdly, batteries are charged more rapidly and with less
attention.
3.2.3 LEAD-ACID BATTERIES
With the constant-current charge method the voltage can climb to 34-37 volts.
Therefore, this method should normally not be used to charge lead-acid batteries,
especially not the sealed type (SLAB). It is preferred to charge a sealed lead-acid
battery in constant-potential mode at a voltage of 28.6 ± 0.2 volts for four hours or
until the charge current drops below one ampere.
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3. OPERATING GUIDE - CHARGING
The constant-current charge method can however be used for reconditioning
SLABs. The current must be set low and the timer set to 12-18 hours. The battery
should be periodically monitored for overheat during reconditioning. When the battery
begins to accept charge current, it can be switched to constant-potential charging set
to 14.5 (12 volt battery) or 28.6 volts (24 volt battery).
3.2.4 NICKEL-CADMIUM BATTERIES
Nickel-cadmium batteries may be initially charged with constant potential set to
14.5 (12 volt battery) or 28.6 (24 volt battery). After the initial charge the batteries
can be topped with a low constant-current (usually C/10
charge to 1.55 volts per cell.
The nickel-cadmium can also be completely charged in the constant-current mode.
The current would be adjusted to a lower rate for topping. A low constant current
applied during a long time can also be used to eliminate fading, previously called the
“memory effect”, from nickel-cadmium batteries.
Refer to your manufacturer’s maintenance manual for the recommended
discharge times.
3.3 PREPARATION FOR CHARGING
Before charging the battery, read the component maintenance manual
(CMM) or the operating and maintenance manual (OMM) for the specific battery.
Ensure that the charge time and current or voltage from the battery manufacturer
are followed.
It is recommended that a visual inspection of the battery is carried out in
conjunction with testing and charging batteries. The charging, unless otherwise
specified in the manufacturer's CMM/OMM, shall be conducted at room ambient
temperature of 70°F to 85°F (21°C to 29°C).
1.1.1 VERIFY END VOLTAGE
The end voltage (in all charge modes) can be verified by the following steps: 1)
turn unit power off; 2) disconnect any battery; 3) turn charge current to max; 4) turn
unit power on; and 5) verify the end voltages on the CA-1550 digital voltmeter (see
also Modify Constant Potential in section 3.5).
WARNING: Always turn the AC power switch off before
connecting or disconnecting a battery
NOTE: Once set, all settings are maintained and need not be
reset for duplicate charging
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3. OPERATING GUIDE - CHARGING
A. SWITCH OFF MAINS POWER
Turn off the AC on-off/reset power switch.
B. TURN DOWN CHARGE CURRENT
Repeatedly turn the Ampere Adjust knob fully
counter-clockwise to set charge current to
zero.
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3. OPERATING GUIDE - CHARGING
3.4 CHARGE TIME
3.4.1 TIMER UNIT SETTING
The CA-1550 has a built in timer, allowing charge time settings from 0.1-
999.9 minutes.
3.4.2 CHARGE TIME SETTING
The charge time will be set based on the state of charge of the battery and at
which rate the battery is being charged.
C. SET TIMER
Set the timer by pushing the up/down buttons
to the required charge time.
D. SELECT CHARGE MODE
Turn the Mode Select knob to the desired
charge mode: 1) Constant potential, CP; or 2)
Constant current, CI.
NOTE: The factory-presets are 14.5 and 28.6
volts in constant-potential mode but can, if
desired, be modified in step E.
3.5 SETTING CHARGE VOLTAGE AND CURRENT
The CA-1550 provides maximum flexibility in setting charge parameters. Both the
current and the voltage can be modified to accommodate different battery voltages
and charge methods.
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3. OPERATING GUIDE - CHARGING
E. MODIFY CONSTANT POTENTIAL
If charging in constant-potential mode (CP),
the constant charging voltage can be
modified. This has to be done before
connecting the battery.
1. Turn on the AC on-off/reset power switch.
2. Turn the Constant Potential Adjust
Trimpot until the desired voltage is
obtained. The voltmeter will display the
voltage as it is being adjusted.
3. Turn off the AC on-off/reset power switch
when voltage has been adjusted.
CAUTION: Ensure the unit is turned off
before connecting the battery.
F. CONNECT BATTERY
Connect the battery DC cable to the battery.
Ensure the connectors are plugged in
completely.
NOTE: The factory-presets are 24.5 and 28.6
volts in constant-potential mode can, if desired,
be modified in step E above.
G. SWITCH ON MAINS POWER
Turn on the AC on-off/reset power switch. The
voltmeter reads the battery terminal voltage,
the ammeter reads zero. The timer reads 0’s
and its red LED is off.
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3. OPERATING GUIDE - CHARGING
H. SET CHARGE CURRENT
1. CONSTANT-CURRENT
CHARGING
Turn the Ampere Adjust knob until the
desired charge current has been reached.
The charge current is displayed on the
ammeter as the current is being adjusted.
2. CONSTANT-POTENTIAL
CHARGING
Turn the Ampere Adjust knob to max (fully
clockwise) or to the desired current limit. The
charge current is displayed on the ammeter as
the current is being adjusted.
NOTE: The CA-1550 has a current limit of 25
amperes.
I. WAIT FOR CHARGE TO AUTOMATICALLY COMPLETE
During the charging of the battery the battery voltage, charge current, and
elapsed charge time are displayed.
1. CONSTANT-CURRENT CHARGING
The current remains constant while the voltage increases during the time of
charging.
2. CONSTANT-POTENTIAL CHARGING
The charger’s end voltage remains constant while the current starts at a
high value and gradually approaches zero as the battery approaches a full
charge.
The actual charge voltage in both modes is determined by the battery, until
the constant voltage is reached (28.6 volts in constant-potential or 35 volts in
constant-current mode).
The test completes when the set charge time has been reached. The Off
lamp illuminates.
For the constant-current method, if a second charging is desired (topping)
repeat steps C, H, and I, with the current adjusted to a lower value (usually
C 1 / 10)
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3. OPERATING GUIDE - CHARGING
K. SWITCH AC POWER OFF
Switch the AC on/off switch off before removing the battery.
NOTE: If in emergency it is required to stop
charging, switch the unit to off. When charging is
restarted the timer is reset to zero. It may be
necessary to adjust the parameters (current and
time) before resuming charge.
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4. OPERATING GUIDE - DISCHARGING
4 OPERATING GUIDE - DISCHARGING
4.1 DISCHARGE CHARACTERISTICS
The lead-acid and the nickel-cadmium cells are generally assigned nominal open
circuit voltages of 2.10 volts and 1.35 volts respectively. Actual open circuit voltage at
75°F/ 25°C for a fully charged battery cell depends on state-of-charge and time
after charge.
During discharge, the voltage of the cell or battery immediately begins to decrease
because of the effective internal resistance of the cell. This includes the resistance of
the terminal posts, active material, plate lugs and grids, separators, and contact
resistance between the surface of the active material and the electrolyte. The
internal resistance increases during discharge, being greater toward the end of
discharge, when the terminal voltage is lower.
As voltage gradually becomes lower during discharge, the point of near exhaustion
is reached. At this point, the discharge voltage curve begins to drop very sharply to
a value which is of no further practical use. Usually this happens at 18-20 volts for
a 24 volt lead-acid battery and 1 volt per cell for a nickel-cadmium battery (see
Figure 4-1).
Battery manufacturers specify a cutoff voltage which the battery must exceed
during a discharge test to have acceptable capacity. The cutoff voltage varies with
the rate of discharge (the discharge current/time combination used to draw the
same capacity). For example, the minimum cutoff voltages for a 30 ampere-hour,
24-volt naval aircraft lead-acid storage battery are generally specified as is shown
in Table 4- 1.
Table 4- 1 Cutoff voltages at different discharge rates for a 30
ampere-hour, 24 volt lead-acid battery
The specified final minimum cutoff voltage represents the value of voltage at which the
rated ampere-hour capacity of the battery must have been delivered for the specified
discharge rate. Figure 4-1 is a typical discharge curve for a 40 ampere-
hour sealed lead-acid (SLAB) aircraft storage battery discharged at a 1-hour rate of
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4. OPERATING GUIDE - DISCHARGING
40 amperes. From Figure 4-1, it is observed that at the end of 1 hour of discharge
time, the battery voltage has reduced only to about 22 volts. Because the minimum
required cutoff voltage is 18 volts at the 1-hour discharge rate, the battery exceeds the
minimum requirements. With increasing hours of use or age, the battery
capacity decreases. Therefore, battery manufacturers usually recommend testing for
a capacity equal to 80% of the original ampere-hour rating.
Figure 4-1. Typical discharge curve for 40 ampere-hour lead-acid aircraft
battery
Figure 4-2 illustrates discharge curves for typical SLABs at different discharge
rates. Note that the cell voltage drops much more rapidly at the higher discharge
rates, i.e. the rates at which a greater current is drawn during a shorter period of
time.
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4. OPERATING GUIDE - DISCHARGING
Figure 4-2. Typical discharge curves for SLABs at different rates
The discharge of a lead-acid battery beyond the point of which exhaustion of the cell
is approached can be harmful, as the battery will form a sulfate deposit on its plates.
This is particularly true if the battery is not soon recharged.
4.2 DISCHARGE CAPACITY TESTING
The purpose of a discharge test is to determine the long-term capacity of the
battery. For a lead-acid aircraft battery, for example, the capacity test is the
amount of current which can be delivered for one hour or until the voltage
decreases to 1.5 volts per cell. This is considered the emergency capacity of the
battery. The result of the test will determine whether to accept or reject the battery
and which steps could be taken to electrically recondition the battery.
The amount of electrical capacity available from a fully charged nickel-cadmium or
lead-acid battery is defined by the capacity rating of the battery and is stated in terms
of ampere-hours. Because of internal resistance, the higher the discharge rate (higher
current during a shorter period of time) demanded of a battery, the less usable
capacity it can supply. See Figure 4-2.
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4. OPERATING GUIDE - DISCHARGING
4.2.1 Constant-Current Discharge Method
The most accurate and repeatable method of measuring capacity is to discharge the
battery at a constant-current rate. This is also the method used by the CA1550. The
load resistance in this method is continuously and automatically varied to maintain a
constant discharge current as the battery's voltage decreases. A schematic of the
circuit diagram for the CA-1550 can be seen in Figure 4-3. At the end of discharge,
the calculation of ampere-hour capacity is the product of discharge current and the
elapsed discharge time.
LOAD RESISTOR
Figure 4-3. Circuit diagram for constant current discharge test
NOTE: Always read the battery manufacturer's operating
instructions. Some lead-acid batteries are recommended at a
20 volt cutoff when tested for an hour at 80% of rated
capacity. Some nickel-cadmium battery requirements are
testing for two hours at half the rated capacity, and a 1 volt per
cell cutoff.
4.3 PREPARATION FOR TESTING
Before starting the discharge test, read the component maintenance manual
(CMM) or the operating and maintenance manual (OMM) for the specific battery to be
tested. Ensure that the discharge rate and cutoff voltage from the battery
manufacturer are followed.
It is recommended that a visual inspection of the battery is carried out in
conjunction with testing and charging batteries.
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4. OPERATING GUIDE - DISCHARGING
The battery must be fully charged before testing starts, except for special tests.
WARNING: Always turn off the AC power switch before
connecting or disconnecting a battery.
NOTE: The test, unless otherwise specified in the
manufacturer's CMM/OMM, shall be conducted at room
ambient temperature of 70°F to 85°F (21°C to 29°C).
A. SWITCH OFF MAINS POWER
Turn off AC on-off/reset power switch.
B. SELECT DISCHARGE MODE
Turn the Mode Select knob to the
“Discharge” setting.
C. TURN DOWN DISCHARGE
CURRENT
Turn the 3-turn Ampere Adjust knob fully
counter-clockwise to set discharge current to
zero. This prevents excess current, which
may be too high for the battery, once the
battery is connected and the discharge test
has begun.
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