CAUTION

Battery Tender® JUNIOR & 12 & 6 Volt Models: WORKING WITH LEAD ACID BATTERIES AND BATTERY CHARGERS:
All lead acid batteries have the potential to emit gasses that may combine into
Battery Tender® PLUS 750 Milliamp & 1.25 Amp a combustible or explosive mixture. In many cases, it is possible that lead acid
Battery Chargers & batteries will emit these gasses during normal discharge and charging
operations. Because of this potential danger, it is important that you follow the
8 Volt Model 1.25 Amp precautions recommended by both the battery and battery charger
manufacturers before using either one.
USING MANUALS: Study all of the battery manufacturer's precautions and
IMPORTANT SAFETY INSTRUCTIONS specific recommendations for safe operation such as not removing cell caps
SAVE THESE INSTRUCTIONS: This manual contains while charging and the recommended rates of charge (charger output current).
important safety and operating instructions for BATTERY TENDER®
CHARGERS, both the 12 & 6 Volt 750 Milliamp BT JUNIOR and 12, 6, CAUTION
CHARGER VOLTAGE COMPATIBILITY: NEVER use a battery charger
& 8 Volt 1.25 Amp BT PLUS models. CAREFULLY READ THESE
unless the battery voltage matches the output voltage rating of the charger.
INSTRUCTIONS BEFORE USING THE BATTERY CHARGER. For example, do not use a 12-volt charger with a 6-volt battery and vice-versa.
CHARGER LOCATION: LOCATE the charger as far away from the battery as
WARNING AND CAUTION LABEL DEFINITIONS: is allowed by the length of the output cable harness. NEVER set the charger
above the battery. NEVER set the charger on a surface constructed from
WARNING combustible material. NEVER place the battery, the charger, or any of the
WARNING indicates a potentially hazardous situation, which, if electrical connections between them in an area that is likely to become wet.
not avoided, could result in serious injury or death. EXCESSIVE MOISTURE: Do not expose the battery charger or any of its
CAUTION electrical connections (either AC or DC) to rain, snow, or extremely high,
CAUTION indicates a potentially hazardous situation, which, if not condensing humidity.
avoided, may result in minor or moderate injury. CHARGER ATTACHMENTS: Do not use attachments that are not
recommended or sold by the charger manufacturer. To do otherwise may
CAUTION
result in the risk of electric shock, fire, or possibly some other unforeseen
CAUTION used without the safety alert symbol indicates a potential personal injury situations.
potentially hazardous situation that if not avoided, may result in HANDLING POWER CORDS: When handling electric power cords, always
property damage. pull by the plug rather than by the cord. This will reduce the risk of damage to
both the plug and cord, and it will minimize the likelihood of electric shock
GENERAL PRECAUTIONS resulting from that damage.
LOCATION OF POWER CORDS: Make sure all electric power cords are
WARNING located so that they cannot be stepped on, tripped over, or otherwise
Battery posts, terminals and related accessories contain lead and subjected to damage or stress.
lead components, chemicals known to the State of California to MONITORING SEALED & NON-SEALED BATTERIES: When leaving a
cause cancer and birth defects or other reproductive harm. battery charger connected to either a sealed (AGM or GEL) or non-sealed
Always wash your hands after handling these devices. (flooded battery) for extended periods of time (weeks, months, etc.),
periodically check the battery to see if it is unusually warm. This is an
WARNING indication that the battery may have a weak cell and that it could go into a
Do not operate the battery charger with damaged AC power cords thermal runaway condition. If the battery releases an excessive amount of gas
or plugs or DC output cords or accessories - Replace accessories or if the battery gets hotter than 130°F (55°C) during charging, disconnect the
charger and allow the battery to cool. Overheating may result in plate
immediately. Since neither the AC power cord nor the DC output
distortion, internal shorting, drying out or other damage. For flooded batteries,
cord can be replaced, if either cord is damaged the battery also check individual cell fluid levels against manufacturer's recommendations
charger should be scrapped. for safe operation.

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392-0154-RA
 WARNING a metal tool near a battery it might spark or create a short circuit between
ELECTRIC SPARK & OPEN FLAME: NEVER smoke or allow a source of the battery terminals and some other metal part. Either event may cause
electric spark or open flame in the vicinity of the battery or engine. (For a dangerous electrical shock hazard, a fire, or even an explosion;
example: Don't charge the battery next to a gas water heater.) 5. Remove all personal metal items such as rings, bracelets, necklaces, and
VENTILATION: Do not operate the charger where ventilation is restricted. watches when working with a lead-acid battery. A lead-acid battery can
The intent here is to allow sufficient airflow to minimize and dissipate the heat produce a short-circuited current high enough to weld a metal ring or other
generated by the charger and to diffuse the gasses that may be emitted by the piece of jewelry, causing a severe burn;
battery. 6. Use BATTERY TENDER® CHARGERS, both12 Volt 750 Milliamp
CHARGER MAINTENANCE: NEVER disassemble the charger or attempt to JUNIOR and 12 Volt 1.25 Amp PLUS models, for charging lead-acid
do internal repairs. Take it to a qualified service technician. Assembling the batteries only. They are not intended to supply power to an extra low-
charger incorrectly may result in the risk of electric shock or create a fire voltage electrical system or to charge dry-cell batteries. Charging dry-cell
hazard. batteries may cause them to burst and cause injury to persons and
damage to property;
WARNING INFORMATION NOTE ABOUT DRY-CELL BATTERIES:
EXTENSION CORDS: An extension cord should not be used unless There are some wet, non-spillable, lead acid batteries on the market whose
absolutely necessary. Using improper extension cord could result in a risk of manufacturers' make the claim that they are dry-cell batteries. These batteries
fire and electric shock. If extension cord must be used, make sure that: are sealed, gas-recombinant, starved electrolyte, possibly with AGM
¾ The pins on the extension cord plug have the same number, size, and (Absorbed Glass Mat) type construction. It is perfectly safe to use BATTERY
shape as those of the AC power cord plug on the charger; TENDER® CHARGERS, both the12 & 6 Volt 750 Milliamp BT JUNIOR
¾ The extension cord is properly wired and is in good electrical condition;
and the 12, 6, & 8 Volt 1.25 Amp BT PLUS models, to charge these types
and
of batteries. The dry-cell battery warning is intended for non-rechargeable,
¾ The wire size is as specified in Table 1 below.
alkaline and other similar types of batteries. If you have any doubt about the
type of battery that you have, please contact the battery manufacturer before
TABLE 1: EXTENSION CORD attempting to charge the battery.
LENGTH & MINIMUM SAFE CONDUCTOR SIZE 7. NEVER charge a visibly damaged or frozen battery.
Note: The smaller the AWG number, the larger the conductor diameter.
Length of Cord (feet) 6 to 100 101 to150 PREPARING TO CHARGE: First, follow all General &
Length of Cord (meters) 1.8 to 30.5 30.8 to 45.6 Personal Precautions as previously explained, and then
Size of Conductor (AWG) 18 16 continue.
Conductor Diameter (mm) 1.25 1.5
WARNING

PERSONAL PRECAUTIONS IF THE BATTERY MUST BE REMOVED FROM THE VEHICLE:

1. To avoid an electric arc (or spark), turn off or disconnect all of the
accessories in the vehicle. Then always remove the cable that is
WARNING connected to grounded terminal from battery first;
WHEN YOU WORK NEAR LEAD-ACID BATTERIES: 2. If necessary, clean the battery terminals. Be careful to keep the corrosion
and other debris from coming in contact with your eyes;
1. Someone should be within range of your voice or close enough to come to 3. If the battery is not a sealed battery, then if necessary, add distilled water
your aid if you have an accident; to each cell until the battery acid solution reaches the level specified by
2. Have plenty of fresh water and soap nearby in case battery acid contacts battery manufacturer. Do not overfill;
skin, clothing, or eyes; 4. Before inserting the charger AC power plug into the electrical outlet, check
3. Wear complete eye protection and protective clothing. Avoid touching your the polarity of the battery posts, and attach at least a 24 inch long 6 (AWG)
eyes while working near a battery. If battery acid contacts your skin or insulated, battery extension cable to the negative battery post. Then
connect the appropriate charger DC output connectors to the battery and
clothing, wash immediately with soap and water. If acid enters an eye, the extension cable, positive to positive and negative to negative. Never
immediately flood the eye with running cold water for at least 10 minutes allow the alligator clips or terminal rings to touch each other after they are
and get medical attention as soon as possible; connected to the battery charger.
4. Be extra cautious when handling metal tools around a battery. If you drop 5. Connect the AC power plug to the electrical outlet.
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 WARNING SPECIAL FEATURES: The BATTERY TENDER® CHARGERS
have the following special features:
IF THE BATTERY REMAINS INSTALLED IN THE VEHICLE: SPARKPROOF: The battery charger DC output leads, either ring
1. DO NOT CONNECT THE CHARGER AC POWER PLUG TO THE
ELECTRICAL OUTLET UNTIL ALL OTHER CONNECTIONS ARE MADE! terminals or alligator clips must be connected to a battery before an output
2. Place both the AC and DC power cords in the best position to avoid voltage is developed by the battery charger.
accidental damage by movable vehicle parts, i.e. hoods, doors, or moving SHORT CIRCUIT PROTECTION: The battery charger can sustain a
engine parts (fan blades, belts, or pulleys). short circuit connection directly across its DC output terminals indefinitely
3. Check the polarity of the battery posts. If the positive (pos, p, +) post is without any risk of either electric shock or excessive heat.
connected to the vehicle chassis, then the vehicle has a positive ground REVERSE POLARITY PROTECTION: The battery charger is
system. If the negative (neg, n, -) post is connected to the vehicle chassis, protected internally against any damage due to the DC output leads being
then the vehicle has a negative ground system. Negative ground systems connected to the opposite polarity battery post. No damage will result to either
are the most common.
4. For negative ground systems, connect the positive (red) alligator clip, or the battery or the battery charger.
ring terminal to the positive battery post. Then connect the negative TEMPERATURE COMPENSATION (BT PLUS Only): The output
(black) alligator clip, or ring terminal to the vehicle chassis. Do not make voltage is compensated at -3.5mV/ °C/Cell. This increases the output voltage
the negative charger clip or ring connection to the carburetor, fuel lines, or in cold climates to keep the battery from being undercharged and, more
thin, sheet metal parts. Make that connection to the engine block or a importantly, reduces the voltage in high temperature climates to protect the
heavy gauge metal part of the frame. battery from overcharge.
5. For positive ground systems, connect the negative (black) alligator clip, or
ring terminal to the negative battery post. Then connect the positive (red) TIME REQUIRED TO CHARGE A BATTERY:
alligator clip, or ring terminal to the vehicle chassis. Do not make the The BATTERY TENDER® CHARGERS charge at a rate of either 0.75 Amps
positive charger clip or ring connection to the carburetor, fuel lines, or thin, (0.75 Amp-Hours per hour) or 1.25 Amps (1.25 Amp-Hours per hour).
sheet metal parts. Make that connection to the engine block or a heavy Therefore, a fully discharged 15 Amp-Hour battery will take approximately 16
gauge metal part of the frame. hours or 9.6 hours respectively, to recharge to 80% capacity. Some large
6. Connect the AC power plug to the electrical outlet.
automotive or marine, deep cycle type batteries may take several days to fully
recharge.
ADDITIONAL CHARGER INFORMATION
WORKING WITH A DEAD BATTERY OR A BATTERY WITH A VERY
AUTOMATIC CHARGING AND BATTERY STATUS LOW VOLTAGE:
If you try to charge a dead battery having a voltage below 3 Volts, the
MONITORING: The BATTERY TENDER® CHARGERS are completely BATTERY TENDER® CHARGERS will not start to charge because an internal
automatic and may be left connected to both AC power and to the battery that safety circuit prevents the battery chargers from generating any DC output
it is charging for long periods of time. However, it is prudent to periodically voltage.
check both the battery and the charger for normal operation during these
extended charging periods. NOTE:
If a 12 Volt, Lead-Acid battery has an output voltage of less than 9 volts when
The charger output power, voltage, and current all depend on the condition of it is at rest, when it is neither being charged nor supplying electrical current to
the battery that is being charged. Both BATTERY TENDER® CHARGERS an external load, there is a good chance that the battery is defective. As a
have status lights that indicate the operating mode of the charger, and the frame of reference, a fully charged 12-Volt, Lead-Acid battery will have a rest-
condition of the battery that is connected to the charger. state, no-load voltage of approximately 12.9 volts. A fully discharged 12-Volt,
Lead-Acid battery will have a rest-state, no-load voltage of approximately 11.4
The chargers operate in one of the 3 primary charge modes: the bulk mode volts. That means that a voltage change of only 1.5 volts represents the full
(full charge power, constant current, increasing battery voltage, battery is 0% range of charge 0% to 100% on a 12-Volt, Lead-Acid battery. Depending on
to 75% or 80% charged), the absorption mode (high constant voltage, the manufacturer, and the age of the battery, the specific voltages will vary by
decreasing current, battery is 75% to 100% charged), or the storage/float a few tenths of a volt, but the 1.5-volt range will still be a good indicator of the
maintenance mode (low constant voltage, minimal charge current, battery is battery charge %.
fully charged, typically 100% to 103%).
STATUS INDICATOR LIGHTS: The following describes the
When the battery is fully charged, the green status indicator light will turn on indicator light operation: Note that the JUNIOR has a single light
and the charger will switch to a storage/maintenance charge mode. Both
BATTERY TENDER® CHARGERS will automatically monitor and maintain the that will shine either RED or GREEN, while the PLUS has two
battery at full charge. separate lights, one RED and one GREEN.

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¾ NEITHER THE RED OR GREEN LIGHT TURN ON (Both models) – This
is an abnormal condition and most likely indicates that the charger is not
properly connected to the AC power.
¾ RED LIGHT FLASHING (All models except 6V Junior) – The red light SPECIFICATION SUMMARY:
flashing indicates that the battery charger has AC power available and that
the microprocessor is functioning properly. If the red light continues to
flash, then either the battery voltage is too low (less than 3 volts) or the Technical Specifications (BT Plus & BTJR Models)
output alligator clips or accessory ring terminals are not connected Input Voltage / Frequency 100 to 132 VAC / 60 Hz
correctly.
¾ RED LIGHT ON STEADY (Both models) – Whenever the red light is on Input Current (Maximum) 0.43 or 0.36 Amps RMS
steady, a battery is connected properly and the charger is charging the
battery. The red light will remain on until the charger completes the Output Current Typical 1.25 or 0.75 Amps DC
charging stage. Output Voltage 12 , 8, & 6 or 12 & 6 Volts DC
¾ GREEN LIGHT FLASHING (1.25A only) - When the green light is
flashing, and the red light is on, the battery is greater than 80% charged Charger Output Voltage Amplitudes throughout the entire
and may be removed from the charger and used if necessary. Whenever charge algorithm, including absorption and float maintenance,
possible, leave the battery on charge until the green light is solid. are consistent with the optimum charging recommendations of
¾ GREEN LIGHT ON STEADY (Both models) - When the green light stops the major lead-acid battery manufacturers.
flashing and burns steady, the charge is complete and the battery can be
returned to service if necessary. Maximum Operating Temperature 50 °C Typical
¾ ALTERNATING RED & GREEN LIGHTS FLASHING (PLUS) This is
abnormal and most likely indicates either that the battery is sulfated or that Charger Case Dimensions:
there is a poor electrical connection between the charger DC output and 0.75 Amp BT JUNIOR: 3.313 in (85 mm) L x 2.313 in (59 mm) W x
the battery posts. 1.875 in (48 mm) H.
1.25 Amp BT PLUS: 4.875 in (124 mm) L x 3.25(83 mm) W x 2.875
in (73 mm) H.
TROUBLESHOOTING CHECK LIST:
Note: When sizing the space available for the 1.25 Amp battery
1. NEITHER OF THE CHARGER LIGHTS TURN ON AFTER THE AC POWER charger, do not forget to allow additional length for safe bending of
PLUG IS CONNECTED TO THE AC ELECTRICAL OUTLET: For the 1.25A the strain relief on AC or DC power cords, typically 1 in (25.4 mm).
model: Check the charger AC power plug connection at the AC electrical outlet.
Verify that the AC electrical outlet is functioning properly by plugging in another Gross Shipping Weight:
appliance or a voltmeter. For the 0.75 A model, also make sure that the charger output BTPlus 1.25 Amp: Approx. 3.0 lbs (1.4 kg)
is properly connected to the battery. BTJR 0.75 Amp: Approx. 1.8 lbs (0.8 kg)
2. THE CHARGER GREEN LIGHT GOES ON IMMEDIATELY WHEN AC
POWER IS APPLIED TO THE CHARGER: The charger connections at the Declaration of Conformity: These battery charger products are
battery may be intermittent, the battery may be defective, or the battery might already designed to meet or exceed the specific requirements of UL-1236.
be fully charged. See UL File E206016.
3. CHARGER IS CHARGING BUT THE GREEN LIGHT DOES NOT TURN ON
IN A REASONABLE AMOUNT OF TIME: The battery may be large and requires Design Conformance & Revision: All charger products are 100%
more time to fully charge than originally expected, there may be another appliance inspected and electrically tested prior to shipment. All battery charger
drawing electric power from the battery while it is charging, or the battery may be designs are proprietary and subject to change without notice.
defective. Also, a newly purchased battery may not be fully charged and may take Manufacturer makes no specific claims nor does it either make or
longer to charge initially. imply any specific guarantee or warranty with respect to either the
4. THE RED LIGHT COMES ON AGAIN AFTER THE GREEN LIGHT CAME physical configuration or performance of any of the battery charger
ON. There may be another appliance drawing electric power from the battery causing products listed herein, including suitability for purpose or
its voltage to drop below the reset level. The battery charger then goes back into full merchantability.
charge mode. Also, the charger connections at the battery may be intermittent or the
battery may be defective.

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