Forney 52720 User manual

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52720
1.5 AMP SLOW • 12 VOLT • BATTERY CHARGER
KEEPS BATTERIES FULLY CHARGED IN STORAGE
POWER TO GET THE JOB DONE
OWNER’S MANUAL
• Automatic over-charging protection
• Short circuit protection
• Reverse hook-up protection
• Overheat protection
• LED battery status indicators
• For sealed lead-acid batteries
• ETL certified. 5-3-1 Warranty
with “Advanced Replacement”

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IMPORTANT SAFETY INSTRUCTIONS
PERSONAL PRECAUTIONS
1. SAVE THESE INSTRUCTIONS – The Forney 52720
offers a wide range of features to accommodate the
needs for home use. This manual will show you how
to use your charger safely and effectively. Please
read, understand and follow these instructions
and precautions carefully, as this manual contains
important safety and operating instructions.
2. WARNING: This product may contain chemicals
known to the State of California to cause cancer,
birth defects and other reproductive harm (CA.
Prop 65). Wash hands after use.
3. Do not expose charger directly to rain or snow.
4. Use only recommended attachments. Use of an
attachment not recommended or sold by Forney
Industries, Inc. may result in a risk of fire, electric
shock or injury to persons or damage to property.
5. To reduce the risk of damage to electric plug or
cord, pull by the plug rather than the cord when
disconnecting the charger.
6. Use of an improper extension cord could result in
a risk of fire and electric shock. Make sure:
• That the pins on the plug of the extension cord
are the same number, size and shape as those
of the plug on the charger.
• That the extension cord is properly wired and in
good electrical condition.
• That the wire size is large enough for the AC
ampere rating of the charger.
1. Consider having someone close enough by to come
to your aid when you work near a lead-acid battery.
2. Have plenty of fresh water and soap nearby in
case battery acid contacts skin, clothing, or eyes.
3. Wear complete eye protection and clothing
protection. Avoid touching eyes while working
near the battery.
4. If battery acid contacts skin or clothing, wash
immediately with soap and water. If acid enters
eye, immediately flood eye with cold running
water for at least 10 minutes and get medical
attention immediately.
5. NEVER smoke or allow a spark or flame in vicinity
of the battery or engine.
6. Be extra cautious to reduce the risk of dropping a
metal tool onto the battery. It might spark or short-
7. Do not operate the charger with a damaged cord
or plug; take it to a qualified service person. (Call
customer service at: 1-800-521-6038)
8. Do not operate the charger if it has received a
sharp blow, been dropped or otherwise damaged
in any way; take it to a qualified service person.
(Call customer service at: 1-800-521-6038)
9. Do not disassemble the charger; take it to a
qualified service person when service or repair is
required. Incorrect reassembly may result in a risk
of fire or electric shock. (Call customer service at:
1-800-521-6038)
10. To reduce the risk of electric shock, unplug the
charger from the outlet before attempting any
maintenance or cleaning.
WARNING – Risk of explosive gases. Working
in the vicinity of a lead-acid battery is dangerous.
Batteries generate explosive gases during normal
battery operation. For this reason, it is of utmost
importance that you follow the instructions each time
you use the charger.
To reduce the risk of battery explosion, follow
these instructions and those published by the
battery manufacturer and the manufacturer of any
equipment you intend to use in the vicinity of the
battery. Review the cautionary markings on these
products and on the engine.
circuit the battery or other electrical part that may
cause an explosion.
7. Remove personal metal items such as rings,
bracelets, necklaces, and watches when working
with a lead-acid battery. A lead-acid battery can
produce a short-circuit current high enough to weld
a ring or the like to metal, causing a severe burn.
8. Use this charger for charging a LEAD-ACID
battery only. It is not intended to supply power
to a low voltage electrical system. Do not use this
battery charger for charging dry-cell batteries that
are commonly used with home appliances. These
batteries may burst and cause injury to persons
and damage to property.
9. NEVER charge a frozen battery.

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PREPARING TO CHARGE
CHARGER LOCATION
1. If it is necessary to remove the battery from the
vehicle to charge it, always remove the grounded
terminal first. Make sure all of the accessories in
the vehicle are off, to prevent arcing.
2. Be sure area around the battery is well ventilated
while the battery is being charged.
3. Clean the battery terminals before attaching the
charger to the battery. During cleaning, keep
airborne corrosion from coming into contact with
your eyes, nose and mouth. Use baking soda and
water to neutralize battery acid and help eliminate
airborne corrosion. Do not touch your eyes, nose
or mouth.
4. Add distilled water to each cell until the battery
acid reaches the level specified by the battery
manufacturer. Do not overfill. For a battery without
1. Never place charger directly above the battery
being charged; gases from the battery will corrode
and damage the charger.
2. Never allow the battery acid to drip onto the
charger when reading the electrolyte specific
gravity or filling the battery.
removable cell caps, such as valve regulated
lead-acid (VRLA) batteries, carefully follow the
manufacturer’s recharging instructions.
5. Read, understand and follow all instructions for
the charger, battery, vehicle and any equipment
used near the battery and charger. Study all of the
battery manufacturer’s specific precautions while
charging and recommended rates of charge.
6. Determine the voltage of the battery by referring to
the vehicle owner’s manual and make sure that the
battery voltage matches the charger output voltage
(12V).
7. Make sure that the charger cable connections are
attached to the battery and ground securely.
3. Do not operate the charger in a closed-in area or
restrict ventilation in any way.
DC CONNECTION PRECAUTIONS
1. Connect and disconnect the DC output cable connections only after removing the AC plug from electric outlet.

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FOLLOW THESE STEPS WHEN BATTERY IS INSTALLED IN VEHICLE
FOLLOW THESE STEPS WHEN BATTERY IS OUTSIDE VEHICLE
A SPARK NEAR THE BATTERY MAY CAUSE A BATTERY EXPLOSION. TO REDUCE RISK OF A SPARK NEAR BATTERY:
A SPARK NEAR THE BATTERY MAY CAUSE A BATTERY EXPLOSION. TO REDUCE RISK OF A SPARK NEAR BATTERY:
1. Position the AC and DC cords to reduce the risk
of damage by the hood, door, and moving or hot
engine parts.
2. Stay clear of fan blades, belts, pulleys, and other
parts that can cause injury.
3. Check the polarity of the battery posts. The POSITIVE
(POS, P, +) battery post usually has a larger
diameter than the NEGATIVE (NEG, N,–) post.
4. Determine which post of the battery is grounded
(connected) to the chassis. If the negative post
is grounded to the chassis (as in most vehicles),
see step 5. If the positive post is grounded to the
chassis, see step 6.
5. For a negative-grounded vehicle: Connect the
POSITIVE (RED) cable clamp from the battery
charger to the POSITIVE (POS, P, +) ungrounded
post of the battery. Connect the NEGATIVE (BLACK)
cable clamp to the vehicle chassis or engine block
away from the battery. Do not connect the cable
clamps to the carburetor, fuel lines, or sheet-metal
body parts. Connect to a heavy gauge metal part
of the frame or engine block.
1. Check the polarity of the battery posts. The POSITIVE
(POS, P, +) battery post usually has a larger
diameter than the NEGATIVE (NEG, N, –) post.
2. Connect the POSITIVE (RED) charger cable clamp
to the POSITIVE (POS, P, +) battery post.
3. Position yourself as far away from the battery as
possible – then connect the NEGATIVE (BLACK)
charger cable clamp to the NEGATIVE (NEG, N, –)
battery post.
6. For positive-grounded vehicle: Connect the
NEGATIVE (BLACK) cable clamp from the battery
charger to the NEGATIVE (NEG, N, –) ungrounded
post of the battery. Connect the POSITIVE (RED)
cable clamp to the vehicle chassis or engine block
away from the battery. Do not connect the cable
clamps to the carburetor, fuel lines, or sheet-metal
body parts. Connect to a heavy gauge metal part
of the frame or engine block.
7. When disconnecting the charger, disconnect
the AC cord, remove the cable connection from
the vehicle chassis, and then remove the cable
connection from the battery terminal.
4. Do not face the battery when making the final
connection.
5. When disconnecting the charger, always do so in
the reverse order of the connecting procedure and
break the first connection while as far away from
the battery as practical.
6. A marine (boat) battery must be removed and
charged on shore. To charge it onboard requires
equipment specially designed for marine use.

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BATTERY CHARGING - AC CONNECTIONS
OPERATING INSTRUCTIONS
CHARGING
This charger is intended for use with 12 volt battery
systems only. The charger contains an electronic
control circuit which safeguards against overcharging
the battery.
1. Connect the battery and AC power following the
previous steps.
2. The POWER ON (red) LED will light when the AC
cord is properly connected. When the battery is
charged the CHARGED (green) LED will light.
3. The charger then automatically switches between
charge mode and maintain mode as necessary.
The CHARGED (green) LED will cycle on when the
battery is at full charge and off when the voltage
drops below a preset level and the charger goes
into charge mode. This cycle will continue, and
the CHARGED (green) LED will stay on for longer
periods of time as the battery becomes more fully
charged.
This battery charger is for use on a nominal 120-volt
circuit and has a grounded plug that looks like the plug
illustrated. The charger must be grounded to reduce
the risk of electric shock. The plug must be plugged
into an outlet that is properly installed and grounded
in accordance with all local codes and ordinances. The
plug pins must fit the receptacle (outlet). Do not use
with an ungrounded system.
DANGER – Never alter AC cord or plug provided
– if it does not fit the outlet, have proper grounded
outlet installed by a qualified electrician. Improper
connection can result in a risk of an electric shock or
electrocution. NOTE: The use of an adapter plug is not
recommended.
CHARGING TIPS
Read this entire manual before using your battery
charger. The following tips serve only as a guide for
specific situations.
• Your charger has been designed NOT to spark if the
ring terminals on the leads accidentally touch one
another, or if the leads are connected in reverse.
• The battery must measure at least 1 volt to start the
charging of the battery. The POWER ON (red) LED
will be on even if the charging is not taking place.
You can verify charging by measuring the battery
voltage and noting an increase in volts.
• This charger is ideally suited for maintaining the
battery charge level for the following applications:
• Storage of a battery during non-seasonal use.
• For vehicles seldom used or placed in storage.
• For improved battery performance during cold
weather.
• For large automotive or marine batteries which are
deeply discharged, it is recommended to recharge it
first with a larger charger (such as a 10 amp) then
use the Forney 52720 to maintain the charge level
of the battery.
MAINTENANCE/CLEANING INSTRUCTIONS
1. Before performing maintenance, unplug and disconnect battery charger.
2. After use, unplug charger and use a dry cloth to wipe all battery corrosion and other dirt or oil from terminals,
cords, and the charger case.
3. Servicing does not require opening unit, as there are no user-serviceable parts.

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STORAGE INSTRUCTIONS
1. Store charger unplugged. Cord will still conduct electricity until it is unplugged from outlet.
2. Store inside, in a dry, cool place.
3. Do not store cable connectors on or around metal or clipped together.
TROUBLESHOOTING
PROBLEM POSSIBLE CAUSE SOLUTION
The charger is making an
audible clicking sound.
This battery charger is
equipped with a self-resetting
circuit breaker. This device
protects the charger from
temporary overloads. In the
event of an overload, the
breaker will trip open and
after a short cooling off period
will reset automatically. This
process is known as cycling
and can be recognized by an
audible clicking sound.
Battery is defective.
Shorted battery cables or ring terminals.
Severely discharged battery, but otherwise
it is a good battery.
Reverse connections at battery.
Have the battery checked.
Circuit breaker cycles when current draw is too
high. Check for shorted cables or cable clamps
and replace if necessary.
The battery may not want to accept a charge
due to a run-down state. Allow charging to
continue until battery has a chance to recover
sufficiently to take a charge. If more than 20
minutes, stop charging and have the battery
checked.
Shut the charger off and correct the lead
connections.
Charger makes a loud buzz
or hum.
Transformer laminations vibrate (buzz).
Shorted Diode Assembly or Output
Rectifier Assembly (hum).
No problem, this is a normal condition.
Have charger checked by a qualified
technician.
POWER ON (red) LED is not
lit. Charger will not turn on
when properly connected.
No power at the receptacle.
Charger is not plugged in.
Poor electrical connection.
Check for open fuse or circuit breaker supplying
AC outlet.
Plug the charger into an AC outlet.
Check power cord and extension cord for loose
fitting plug.
The battery is connected and
the charger is on, but is not
charging.
Cable clamps are not making a good
connection to the battery.
Connections are reversed.
Battery is defective (will not accept a charge).
Severely discharged battery, but otherwise
it is a good battery.
Check for poor connection to battery and
frame. Make sure connection points are clean.
Unplug the charger and reverse the battery
connections.
Have battery checked.
The battery must measure at least 1 volt to start
the charging process. If it is under 1 volt you
must charge it using a separate charger to get
the voltage up to at least 1 volt before you can
use the Forney 52720.
When you start the battery
charger without an electric load
or battery connected and you
input 120V AC into the charger,
the output port will show no
voltage if tested with a meter.
This is an advantage design to avoid
sudden short circuit through two clamps.
It is normal.
Once you connect the battery charger with a
driving voltage to the output port (the driving
voltage must be equal or higher than 1.2V DC),
you will see on the output port that the output
voltage rises from 0 V DC to about 13.15 V DC
immediately.

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5/3/1 LIMITED WARRANTY
FORNEY INDUSTRIES, INC. 1830 LAPORTE AVENUE, FORT COLLINS CO 80521 MAKES THIS LIMITED
WARRANTY TO THE ORIGINAL RETAIL PURCHASER OF THIS PRODUCT. THIS LIMITED WARRANTY IS NOT
TRANSFERABLE OR ASSIGNABLE.
Subject to the terms and conditions below, Forney Industries, Inc. of Fort Collins, Colorado warrants this
product to the original retail purchaser, to be free from defects in material and workmanship for a period of
one, three or five years (as specified below) from the date of sale. Within the warranty periods listed below,
Forney will replace or repair any warranted parts or components that fail due to defects in material or
workmanship. Proof of purchase is required.
For warranty service, return the product, with proof of purchase to Forney Industries, Inc., 3900 Canal
Drive, Fort Collins, CO 80524 or contact customer service at 1-800-521-6038. "Advanced Replacement",
at Forney’s option, requires the product must be registered within thirty (30) days of the date of purchase.
Registration on line is available at www.forneyind.com.
Forney Industries must be notified in writing within thirty (30) days of any equipment failure that begins within
the warranty time periods. All implied warranties begin on the delivery date of the equipment to the original
retail purchaser.
1. 5 Years – Parts & Labor or Full Replacement: Transformer
2. 3 Years – Parts & Labor or Full Replacement: All components and parts inside the battery charger cover
with the exception of the transformer
3. 1 Year – Parts & Labor (90 days for industrial use): All components and parts outside the battery charger
cover, Included but not limited to cables, clamps. Knobs, wheels and axle are not covered.
4. Consumable components that fail due to normal wear are not covered under this warranty.
5. Equipment that has been modified or changed by any one other that Forney Industries or their authorized
repair station, or equipment that has been improperly installed or operated or misused based on industry
standards, or equipment that has not had reasonable and necessary maintenance or equipment which has
been used for purposes outside of the specifications or the original intended use is not covered by this warranty.
Forney makes no other warranties, including warranty for any accessories used with this product that are
not manufactured by Forney Industries and/or approved for use with this product. This ‘Limited Warranty” is
void if the product is misused, subjected to abuse or is repaired or modified by anyone other than Forney or
its authorized repair station. It is the purchaser’s obligation to read and follow the instructions provided in the
owner’s manual. Using this product in any other way than its original intended use will void the warranty.
Forney Industries, Inc.
1830 LaPorte Avenue
Fort Collins, CO 80526
800-521-6038
www.forneyind.com