Schumacher SC-300A User Manual

Battery
Charger
Model:

SC-300A
3 Amp Automatic Battery Charger
For 12-Volt Lead-Acid Batteries

Owner's Manual

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Important Safety Instructions

Read Rules for Safe Operation and Instructions Carefully

Working in 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.

WARNING: Handling the cord on this product or cords associated with accessories sold with this product, will expose you to lead, a
chemical known to the State of California to cause cancer and birth defects or other reproductive harm.

A. GENERAL BATTERY SAFETY

Wash hands after handling.

INTRODUCTION

Your battery charger has been designed to provide years of ser­vice. This instruction manual contains information on safety, op­eration, and maintenance of your new charger. Make sure that
you are familiar with this information before using the charger.

This battery charger is ideal for recharging batteries in snowmo­biles, ATVs, garden tractors and motorcycles. It also will warm
large batteries found in automobiles and marine applications.

1. Before you use your battery charger, be sure to read all
instructions written in the manual, on the charger and carton.

2. Do not expose to rain or snow.

3. The use of an attachment not recommended or sold by the
charger manufacturer may result in a risk of fire, electric
shock, or injury to persons.

4. To reduce risk of damage to electric plug and cord, pull by
plug rather than the cord when disconnecting charger.

5. An extension cord should not be used unless absolutely
necessary. Use of improper extension cord could result in a
risk of fire and electric shock. If an extension cord must be
used, make sure:

a) the pins on plug of extension cord are the same number,

size and shape as those of plug on charger.

b) the extension cord is property wired and in good electrical

condition; and

c) the wire size is large enough for AC ampere rating of

charger as specified in the following chart.

6. Do not operate the charger with damaged cord or plug replace
them 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 service person.

8. Do not disassemble charger; take it to a qualified service
person when service or repair is necessary. Incorrect
assembly may result in a risk of electric shock or fire.

9. To reduce risk of electrical shock, unplug the charger from
outlet before attempting any maintenance or cleaning.

10. 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 THE UTMOST IMPORTANCE THAT
EACH TIME BEFORE USING YOUR CHARGER; YOU READ
THIS MANUAL AND FOLLOW THE INSTRUCTIONS
EXACTLY.

To reduce the risk of battery explosion, follow these
instructions and those published by the battery manufacturer.
Review the cautionary markings on the battery charger and
battery.

Length of cord (feet): 25 50 100 150

AWG size of cord: 18 18 16 14

SCHUMACHER ELECTRIC CORPORATION

801 BUSINESS CENTER DRIVE • MOUNT PROSPECT, ILLINOIS 60056-2179

Send Warranty Product Repairs to: 1025 E. Thompson, Hoopeston, IL 60942-0280

Call Customer Service if you have questions: 1-800-621-5485

00-99-000507/0205

B. PERSONAL PRECAUTIONS

1. Someone should be within range of your voice, or close
enough 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 eye protection and clothing protection. Avoid touching
eyes while working near a battery.

4. If battery acid contacts skin or clothing, immediately wash
with soap and water. If acid enters eye, immediately flood
with running cold water for at least 15 minutes and get medical
attention immediately.

5. Never smoke or allow a spark or flame in the vicinity of battery
or engine.

6. Do not drop a metal tool onto the battery. It might spark or
short-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 near a lead acid battery.

8. Use the charger for charging a lead-acid battery only. It is
not intended to supply power to a low-voltage electrical
system other than in an automotive application. 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 or damage to property.

9. Never charge a frozen battery.

If necessary to remove battery from vehicle to charge, always
remove grounded terminal from the battery first. Make sure
all accessories in the vehicle are off, so as not to cause an
arc.

C. PREPARING TO CHARGE

1. Be sure area around the battery is well ventilated while battery
is being charged. Gas can be blown away by using a piece
of cardboard or other non-metallic material as a fan.

2. Add distilled water in each cell until battery acid reaches levels
specified by the battery manufacturer. This helps purge gas
from cells. Do not overfill. For a battery without cell caps,
carefully follow manufacturer’s instructions.

3. Study all battery manufacturer’s specific precautions such
as removing or not removing cell caps while charging and
recommended rates of charge.

4. Determine voltage of battery by referring to vehicle owner’s
manual.

DANGER - Never alter the AC plug provided - if it will not fit the
outlet, have a proper outlet installed by a qualified electrician.
Improper connection can result in the risk of electrical shock.

WARNING - Connect and disconnect the battery clamps only
when the AC power cord is disconnected or arcing may result.

CAUTION - Do not expose to rain; replace damaged cords or
wires immediately.

D. BATTERY CHARGER LOCATION

1. Locate charger as far away from battery as DC cables permit.

2. Never place charger directly above battery being charged.

3. Never allow battery acid to drip on charger when reading
specific gravity or filling battery.

4. Do not operate charger in a closed-in area or restrict
ventilation in any way.

5. Do not set battery on top of charger.

E. DC CONNECTION PRECAUTIONS

Connect and disconnect DC clamps only after removing charger AC power cord from the wall outlet. Do not permit clamps to touch each
other.

F. CHARGING BATTERY INSTALLED IN VEHICLE

Follow these steps when battery is installed in vehicle. A spark near battery may cause battery explosion. To reduce the risk of a

spark near the battery:

1. Position AC power cord and DC output cord 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 to persons.

3. Check polarity of battery posts. Positive battery post is usually
larger diameter than the Negative post.

4. Determine which post of battery is grounded (connected) to
the chassis. If negative post is grounded to the chassis (as
in most cases), see Item 5. If Positive post is grounded to
the chassis, see Item 6.

5. For negative grounded vehicle, connect Positive clamp from
charger to Positive ungrounded post. Connect Negative

(Black) clamp to vehicle chassis or engine block away from
battery. Do not connect to carburetor, fuel lines or sheet metal
body parts. Connect to a heavy-gauge metal part of the frame
or engine block.

6. For positive-grounded vehicle, connect Negative (Black)
clamp from charger to ungrounded Negative (Black) post of
battery. Connect positive (Red) clamp to vehicle chassis or
engine block away from battery. Do not connect to carburetor,
fuel lines, or sheet metal body parts. Connect to a heavy­gauge metal part of the frame or engine block.

7. When disconnecting charger, disconnect at wall receptacle,
remove clamp from vehicle chassis and then remove clamp
from battery post.

G. CHARGING BATTERY OUTSIDE OF VEHICLE

Follow these steps when battery is outside of vehicle:

1. Check polarity of battery posts. Positive battery post is usually

a larger diameter than the Negative post.

2. To keep a safe distance from the battery, attach at least a
24-inch long, 18-gauge or heavier insulted jumper cable to
the Negative battery post.

3. Connect Positive (Red) charger clamp to Positive post of the
battery.

4. Position yourself and free end of the cable as far away from
the battery as possible, then connect the Negative clamp to
the free end of the cable. Do not face battery when making
this final connection.

5. When disconnecting charger, always do so in reverse
sequence of connecting procedure and disconnect the first
connection while as far away from the battery as possible.

6. A marine (boat) battery must be removed and charged on
shore. To charge it on board requires equipment specially
designed for marine use.

This battery charger is equipped with an output cord that termi­nates with a (2) two pin polarized connector. See Fig. #1 below.

When making connections to the battery, use the polarized out­put attachment cord supplied (Fig. #2). Warning: For your safety,
before connecting and disconnecting this attachment, remove the
AC power cord from electrical outlet. NOTE: When not in use,
store all cords and connectors in a clean, dry place and protect
them from damage.

Negative



Positive



Red

Positive





Negative
Black

FIG. 2

If ring connectors are attached to the battery, as shown in Fig.
#3, you may quickly disconnect the charger from the battery by
pulling the connectors apart. By purchasing additional output
cords, you can increase the usage of the charger, for instance,
have one attachment cord for a motorcycle another for a lawn
tractor battery or ATV etc. Call 1-800-621-5485 for details.

Negative

(Ribbed Lead)

FIG. 1

Positive

Quick-Disconnect

H. OPERATING INSTRUCTIONS

1. For use with 12 volt batteries only.

2. Connect charger to a battery as outlined in Section F or G.

3. Plug AC power cord into 120 AC volt receptacle.

4. The amber light indicates battery is being charged. The green
light indicates battery is fully charged. The red light signifies
that connection to the battery is hooked up incorrectly.
Reverse clips or rings.

5. When the charger is plugged into an AC outlet but not
connected to a battery the green light will illuminate. For
proper operation, the battery charger must be plugged into
an AC outlet and connected to a battery.

6. When properly connected the amber light should be
illuminated until the battery voltage reaches approximately

14.4 volts, then turns off and the green light turns on,
indicating that the battery has reached full charge.

7. When the green light is on, output from the charger to the
battery is turned off and the battery voltage will began to
drop. When the battery drops to 13.2 volts, output to the

battery is turned on again until the battery voltage once again
reaches approximately 14.4 volts. This cycling will maintain
the battery at its full charge state without over charging the
battery. It will continue as long as the charger is plugged in
and connected to a battery. If the battery is connected to a
circuit that occasionally draws current from the battery, the
on portion of the charge cycle will remain on until the battery
once again reaches approximately 14.4 volts.

8. NEVER leave the battery connected to the charger while
the charger is unplugged from the AC outlet. The reason is
that the charger draws a few milli amperes from the battery,
which will eventually run down the battery.

9. Battery types: Most automotive and marine starter, deep
cycle, AGM and gel type batteries can be charged and
maintained.

CAUTION - To reduce risk of fire or electric shock, connect bat­tery charger directly to grounding receptacle (three-prong). An
adapter should not be used with battery charger.

Ring

Connectors



Harness



FIG. 3

I. CHARGER MAINTENANCE AND CARE

Clean the clamps each time you are finished charging. Wipe off any battery fluid that may have come in contact with the clamps to
prevent corrosion.

Coil the output cord neatly when storing the charger. This will prevent accidental damage to the cord and charger.

J. INDICATION OF A FULLY CHARGED BATTERY

A hydrometer reading of the specific gravity of the electrolyte (fluid) of the battery in good condition should be between 1.25 and 1.285.
When the battery reaches 80 - 85% of full charge, bubbles will appear on the surface of the fluid. As the battery nears full charge,
bubbling will become more vigorous.

K. CHARGING TIMES

This battery charger has a rated output of 3 ampere. This output will vary with the age and condition of the battery being charged.

Amp Hour Average Charge

Battery Charger Times in Hours

4 1.5 – 2
10 3.5 – 4
20 7 – 8
30 11 – 12
45 16.5 – 17
60 22 – 23

LIMITED WARRANTY

Schumacher Electric Corporation makes this limited warranty to the original purchaser at retail of this product. This limited warranty
is not transferable.

Schumacher Electric Corporation warrants this battery charger for two years from date of purchase at retail against defective
material or workmanship. If such should occur, the unit will be repaired or replaced at the option of the manufacturer. It is the
obligation of the purchaser to forward the unit together with proof of purchase, transportation and / or mailing charges prepaid to the
manufacturer or its authorized representative. This limited warranty is void if the product is misused, subjected to careless handling,
or repaired by anyone other than the factory or other authorized factory representative.

The manufacturer makes no warranty other than this limited warranty and expressly excludes any implied warranty including any
warranty for consequential damages.

This is the only express limited warranty and the manufacturer neither assumes nor authorizes anyone to assume or make any other
obligation towards the product other than this express limited warranty. The manufacturer makes no warranty of merchantability or
fitness for purpose of this product and expressly excludes such from this limited warranty. Some states do not allow the exclusion or
limitation of incidental or consequential damages or length of implied warranty so the above limitations or exclusions may not apply
to you. This warranty gives you specific legal rights, and you may have other rights which vary from state to state.