Forney 52721 User manual

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52721
2 AMP TRICKLE • 6 AMP MEDIUM • BATTERY CHARGER
6 & 12 VOLT • AUTOMATIC SHUT OFF
POWER TO GET THE JOB DONE
OWNER’S MANUAL
• 2 Amp trickle charge at 6V & 12V
• 6 Amp medium charge at 12V
• Automatic operation
• Over-charging protection at 12V
• Reverse hook-up protection
• Short circuit protection
• Overheat protection
• Easy-to-read meter
• ETL certified. 5-3-1 Warranty with
"Advanced Replacement"

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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 each time before using your
charger, you read this manual and follow the instructions exactly.
This unit contains or emits chemicals known to the State of California to cause cancer and birth defects or
other reproductive harm. Wash hands after handling.
SAFETY PRECAUTIONS
WARNING
1. Before you use your battery charger, be sure to
read all instructions and cautions printed on:
• Battery Charger
• Battery
• Vehicle or unit using battery
2. Use battery charger on LEAD ACID type
rechargeable batteries only, such as used in autos,
trucks, tractors, airplanes, vans, RVs, trolling
motors, etc. Charger is not intended to supply
power to low-voltage electrical system other than in
an automotive application.
WARNING: Do not use 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.
3. Use only attachments recommended or sold by
manufacturer. Use of non-recommended attachments
may result in fire, electric shock, or injury.
4. When disconnecting the battery charger, pull by
the plug not by the cord. Pulling on the cord may
cause damage to cord or plug.
5. Locate battery power cord so it cannot be stepped
on, tripped over, or subjected to damage or stress.
6. Do not operate charger with damaged cord or
plug. Have cord replaced immediately.
7. Do not operate charger if it has received a sharp
blow, been dropped, or otherwise damaged in
any way. Take it to a qualified professional for
inspection and repair.
8. Do not disassemble charger. Take it to a qualified
professional when service or repair is required.
Incorrect reassembly may result in electric shock
or fire.
9. To reduce risk of electric shock, unplug charger
from outlet before attempting any maintenance or
cleaning.
10. Do not use an extension cord unless absolutely
necessary. Use of an improper extension cord could
result in fire or electric shock. If an extension cord must
be used, make sure that:
• Pins on plug of extension cord are the same
number, size, and shape as those of plug on
charger.
• Extension cord is properly wired and in good
electrical condition.
• Wire size is large enough for AC ampere rating
of charger, as specified below:
Length of cord (feet): 25 50 100 150
AWG size of cord: 18 18 18 16
11. Always charge battery in a well ventilated area.
NEVER operate in a closed-in or restricted area
without adequate ventilation. WARNING: Risk of
explosive gas.
12. Position charger as far away from battery as DC
charger cables permit.
13. Do not expose charger to rain or snow.
14. NEVER charge a frozen battery. If battery fluid
(electrolyte) is frozen, bring into a warm area to
thaw before charging.
15. NEVER set a battery on top of charger.
16. NEVER place charger directly above battery being
charged. Gases from battery will corrode and
damage charger.
17. NEVER touch the battery clips together when the
charger is energized.
18. NEVER crank engine with charger attached to
battery. WARNING: Battery chargers get hot
during operation and must have proper ventilation.
Air needs to flow around entire charger. Do not
set on flammable items like carpeting, upholstery,
paper, cardboard, etc. Will damage leather and
melt plastic and rubber.

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PERSONAL PRECAUTIONS AND SAFETY
PREPARING TO CHARGE
1. WARNING: Wear complete eye protection and
clothing protection when working with lead-acid
batteries.
2. Make sure someone is within range of your voice
or close enough to come to your aid when you
work with or near a lead-acid battery.
3. Have plenty of fresh water and soap nearby for
use if battery acid contacts skin, clothing, or eyes.
If battery acid contacts skin or clothing, wash
immediately with soap and water.
4. Avoid touching your eyes while working with a
battery. Acid particles (corrosion) may get into
your eyes! If acid enters your eye, immediately
flood eye with running cold water for at least 10
minutes. Get medical attention immediately.
1. Make sure you have a 12 volt or 6 volt lead-
acid battery and select battery charger switch
accordingly.
2. Clean battery terminals. Take care to keep
corrosion from coming in contact with your eyes.
3. If required, add distilled water in each cell until
battery acid reaches levels specified by battery
manufacturer. This helps purge excessive gas from
cells. Do not overfill. For a battery without cell
caps, carefully follow manufacturer’s recharging
instructions.
4. Study all battery manufacturer’s specific precautions,
such as removing or not removing cell caps while
charging, and recommended rates of charge.
5. Remove all 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.
6. Take care not to drop a metal tool or other metal
onto the battery. Metal may cause sparking or
short circuit the battery or another electrical
device. Sparking may cause an explosion.
7. Always operate battery charger in an open, well
ventilated area.
8. NEVER smoke or allow a spark or flame in the
vicinity of the battery or engine. Batteries generate
explosive gases!
5. Be sure area around battery is well ventilated
while battery is being charged. Gas can be
forcefully blown away by using a piece of
cardboard or other non-metallic material as a fan.
6. If necessary to remove battery from vehicle to
charge, always remove grounded terminal from
battery first. Make sure all accessories in the
vehicle are off, so as not to cause an arc.
7. A marine (boat) battery must be removed and
charged on shore. To charge it on board requires
equipment specially designed for marine use.
8. Select the proper charge rate and voltage setting

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READING METER
DC AMPS DC AMPS DC AMPS
CHARGED CHARGED CHARGED
FULLY DISCHARGED BATTERY
Initial charge current to the
battery is typically 10 Amps.
2 AMP SETTING: Will not indicate on meter. Charging time will be 2 to 24 hours depending on state of charge,
size and type of battery
APPROACHING FULL CHARGE
Charge current to the battery is
typically 6 Amps.
FULLY CHARGED BATTERY
Charge current to the battery is 0
Amps and the green LED is on.
% 100 75 50 25 % 100 75 50 25 % 100 75 50 25
CIRCUIT BREAKER
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 circuit 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.
NOTE: Clicking sound is normal. Wait until charger
automatically resets itself.
CAUTION: Persistent clicking (more than 30 minutes)
may indicate reverse connection or shorted battery
cells. (See TROUBLESHOOTING)
PERCENT OF CHARGE
The percent of charge scale is intended as a visual aid to help simplify reading the state of charge. It is scaled
for use with the 6 amp charge rate only. The percent of charge is based on current drawn by the battery. For this
reason accuracy will vary with the size and battery type. Typically a 28 ampere hour gel cell battery will draw
less current at the end of a charge than a 140 ampere hour wet cell battery. This means that the indication for a
fully charged large battery may be slightly less than 100%.
BATTERY CHARGER CONTROLS
CHARGE RATE AND VOLTAGE SWITCH SETTING
For 12 volt batteries either 2 or 6 amp charge rate
may be selected. For 6 volt batteries, only the 6 amp
rate (Manual Function) is available. You may use either
the 2 or 6 amp charge rate on large batteries. For
batteries rated 28 ampere hours and less, use the 2
amp charge rate. The smaller the battery the greater
the risk of harming it by using the 6 amp charge rate.
NOTE: It is important to determine the battery type
before charging. 6 VOLT BATTERIES HAVE MANUAL
CHARGE OPTION ONLY.

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BATTERY TYPES
OPERATING INSTRUCTIONS: CHARGING BATTERY OUT OF THE VEHICLE
Three basic types of lead-acid batteries can be given a charge with this charger: (1) Conventional and Low
Maintenance, (2) Maintenance Free, (3) Deep Cycle
1. Check polarity of battery posts. Battery case will
be marked by each post: POSITIVE (POS, P, +)
and NEGATIVE (NEG, N, -). NOTE: The positive
battery post usually has a larger diameter than the
negative post.
2. Attach a 24-inch long (or longer) 6-gauge (AWG)
insulated battery cable to NEGATIVE (NEG, N, -)
battery post. (Purchase cable separately.)
3. Connect POSITIVE (RED) charger clamp to
POSITIVE (POS, P, +) battery post. Rock clamp
back and forth to make good connection.
4. Position yourself and free end of 24-inch cable as
far away from battery as possible. Then connect
NEGATIVE (BLACK) charger clamp to free end
of cable. WARNING: Do not face battery when
making final connection. Rock clamp back and
forth to make a good connection. FIGURE 1 shows
the connection.
5. Plug charger AC cord into 120 volt outlet.
6. Select amperage.
Conventional and Low Maintenance Batteries. These
are the antimony/lead batteries. Conventional/Low
Maintenance batteries require periodic addition of
water to the acid solution (electrolyte). Additional
water may be added by removing the filler caps
located on the top of the battery.
IMPORTANT: When antimony is known to be one of
the materials used in the battery’s construction, that
battery is a Low Maintenance/Conventional type.
CAUTION: Some Low Maintenance batteries have a
relatively smooth top without any apparent battery
filler caps. If, however, the battery manufacturer/
distributor recommends periodic checking of electrolyte
level and provides access to the battery for water
additions, the battery is probably a Low Maintenance/
Conventional type.
Maintenance Free Batteries. These are calcium/lead
batteries and normally do not require water additions.
Therefore, filler caps have been removed from the
battery surface. These batteries will have a smooth or
sealed appearance.
Deep Cycle Batteries. These heavy duty batteries are
used in boats, construction equipment, sump pumps,
etc. They are normally marked DEEP CYCLE on the
outside of the case.
When charging battery out of the vehicle, take care to determine the battery type. To reduce risk of a spark near
battery, follow these steps when battery is outside vehicle.
WARNING: A spark near battery may cause battery explosion. WARNING: When removing battery from vehicle
or boat, disconnect grounded post first. When disconnecting, make sure all accessories are off, so as not to cause
an arc. (NOTE: A marine (boat) battery must be removed and charged on shore. (To charge on board requires
special equipment designed for marine use.) WARNING: When reinstalling battery, attach the ground post first.
7. When battery is fully charged, unplug charger
from AC power source.
8. When battery is fully charged and charger
is unplugged, (1) remove clamp from end of
Negative end of cable, and (2) remove clamp from
Positive battery post, in that order.
9. Clean and store battery charger.
+ –
24", 6 GUAGE CABLE
FIGURE 1
POWER
CORD
BATTERY
CHARGER
NEGATIVE
POSITIVE
BATTERY
TO GROUNDED
POWER OUTLET

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OPERATING INSTRUCTIONS: CHARGING BATTERY IN VEHICLE
When charging battery in vehicle, take care to determine the battery type and which pole is grounded. To
reduce risk of a spark near battery, follow these steps when battery is inside vehicle. WARNING: A spark near
the battery may cause battery explosion.
1. Position AC power cord and DC charging cords to
reduce risk of damage by hood, door, or moving
engine parts.
2. Stay clear of fan blades, belts, pulleys, and other
parts that can cause injury.
3. Check polarity of battery posts. Battery case will
be marked by each post: POSITIVE (POS, P, +)
and NEGATIVE (NEG, N, -). NOTE: The positive
battery post usually has a larger diameter than the
negative post.
4. Determine which post of battery is grounded
(connected) to chassis. NOTE: The negative post is
normally grounded.
NEGATIVE GROUNDED POST
5A. For negative-grounded vehicle, connect POSITIVE
(RED) clamp from battery charger to POSITIVE (POS,
P, +) ungrounded post of battery. Connect NEGATIVE
(BLACK) clamp to vehicle chassis or engine block
away from battery. Connect to a heavy-gauge metal
part of the frame or engine block.
WARNING: Do not connect clip to carburetor, fuel
lines, or sheetmetal body parts. NOTE: Attach clamps
to battery post and twist or rock back and forth several
times to make a good connection. This tends to keep
clamps from slipping off terminals and helps to reduce
risk of sparking.
POSITIVE GROUNDED POST
5B. For positive-grounded vehicle, connect NEGATIVE
(BLACK) clamp from battery charger to NEGATIVE
(NEG, N, -) ungrounded post of battery. Connect
POSITIVE (RED) clamp to vehicle chassis or engine
block away from battery. Connect to a heavy-
gauge metal part of the frame or engine block.
6. Select amperage.
7. Plug charger AC cord into a grounded 120 volt
outlet.
8. WARNING: Be sure area around battery is well
ventilated while battery is being charged.
9. When battery is fully charged, unplug charger
from AC power source.
10. Remove charger clamps in order of grounded
(metal surface) first and battery post second.
11. Clean and store battery charger.
MAINTENANCE/CLEANING INSTRUCTIONS
Very little maintenance is required for the battery charger. Follow common sense in wiping the charger clean
and store in a clean, dry area.
1. After use, use a dry cloth to wipe all battery corrosion and other dirt or oil from clamp, cord, and the charger case.
2. Secure battery charger cords to prevent damage and premature wear.
3. Have any cracked or frayed cords replaced by a qualified professional.
4. Store battery charger in a clean, dry area.

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TROUBLESHOOTING
The battery charger is designed to work automatically. However, If a problem does occur, check the following:
PROBLEM POSSIBLE CAUSE SOLUTION
No meter reading. Charger is not plugged in
Connections are reversed.
Poor electrical connection.
AC outlet is dead.
Battery is defective (will not accept
charge).
Plug in
With charger unplugged, reverse clamps and
reconnect (rock back and forth to bite in).
Clean clamps and battery poles and
reconnect (rock back and forth to bite in).
Plug in a lamp or other appliance to check
for voltage.
Have battery checked.
Charger will not turn on
when properly connected to
power.
Battery recently used in vehicle and is
fully charged.
Battery does not need changing.
(If battery is in vehicle, turning on headlights
will lower battery voltage in a few seconds
and charger should then turn on.)
Battery has less than .7 volts, set to Manual
and retry.
Charger will not turn OFF. Battery has a problem and will not take
a full charge.
Have battery checked. (If in MANUAL,
switch to AUTOMATIC).
Meter needle pulses
(fluctuates) every few
seconds AFTER THREE
HOURS without slowing
down.
Two or more batteries connected in
parallel.
Battery of 200 ampere hours or larger.
Battery is connected to application
that draws a small current (such as a
vehicle's dome light).
Requires more time to charge: continue
charging.
Requires more time to charge: continue
charging.
Requires more time to charge: continue
charging.
Charging current is less than
full output rating of charger.
Battery is partially charged.
Battery is defective (battery plates are
crusted) and will not accept a full charge.
AC power supply is low.
Continue charging.
Have checked and replace battery.
Plug charger into another grounded AC outlet.
Meter needle moves to
extreme right, remains a
short time, then returns to
zero, accompanied by a
clicking sound.
Severely discharged battery (but
otherwise good battery).
In MANUAL with battery connections
reversed.
Battery is defective (will not accept charge)
Charger is cycling after circuit breaking
overload.
Allow charging to continue until battery has
recovered sufficiently to take a charge (Circuit
breaker will continue to cycle and needle will
swing side to side until battery has recovered).
Unplug charger and change to correct
connections.
Have battery checked.
Wait until charger automatically resets itself
(DO NOT RETURN FOR SERVICE).

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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