12V Lithium Jump Starter SL1672

Schumacher 12V Lithium Jump Starter SL1672

The Schumacher SL1672 is a portable 12V lithium jump starter and power pack designed to help start vehicles with discharged 12V batteries. It provides up to 1000 peak amps of jump-starting power and uses an internal 23.68 Wh lithium-ion polymer battery.

In addition to jump-starting vehicles, the SL1672 includes a 10W wireless charging pad, USB-A and USB-C charging outputs, and a built-in LED light with steady, SOS, and strobe modes.

The unit uses a smart jumper cable assembly with built-in protection indicators for reversed battery connections, short circuits, and temperature-related conditions. Four battery status LEDs display the internal battery’s approximate remaining charge.

Product Features

The Schumacher SL1672 combines vehicle jump-starting functions with portable charging and emergency lighting.

Its main features include:

• 12V vehicle jump-starting capability.
• 1000A peak jump-start output.
• 23.68 Wh lithium-ion polymer internal battery.
• Smart jumper cables with connection and fault indicators.
• 10W wireless charging pad for compatible devices.
• USB-A charging output.
• USB-C charging output.
• USB-C input for recharging the power pack.
• Four LED battery status indicators.
• Built-in LED light with three operating modes.
• Manual override function for certain extremely low-voltage battery conditions.
• Automatic protective functions and status indications.

Technical Specifications

Schumacher SL1672 Specifications

SL1672, SL1673, and SL1674 Model Comparison

The English specifications list the SL1673 at 1250A peak, while the Spanish and French specifications list 1000A peak. The rating should be confirmed against the product identification or with Schumacher when required.

Parts and Components

The component diagram identifies the main external parts, controls, charging connections, and jump-starting accessories.

Parts Identification

Jump-Starting Accessories

The manual identifies the following cables used with the unit:

• SA946 smart jumper cable assembly: The recommended cable for connecting the jump starter to a vehicle battery.
• USB-A to USB-C charging cable: The charging cable identified in the product’s component list.

An 18W USB charging adapter is not included.

Control Panel and Button Functions

The SL1672 has a Power button, a Light button, four battery status LEDs, and a smart jumper cable assembly with separate indicator lights.

Power Button

The Power button controls portable charging functions and displays the internal battery level.

• Press the Power button to activate the USB and wireless charging functions.
• Press the button to check the internal battery status.
• Press and hold the button for one second to switch off active functions.

Light Button

The Light button controls the built-in LED light.

• Press and hold the Light button for approximately two seconds to switch on the light.
• Press and release the button to move between lighting modes.
• Press and hold the button until the light switches off.

Override Button

The Override button is located on the smart jumper cable assembly.

It permits a manual jump-starting mode when the vehicle battery voltage is too low for the jump starter to detect a normal battery connection.

Warning: Override mode bypasses a safety function and energizes the battery clamps. Incorrect connections can cause sparks, short circuits, and damage to the battery, jump starter, or vehicle electrical system.

Battery Status LED Guide

Four LEDs indicate the approximate charge level of the internal battery.

Battery Charge Indicators

Press the Power button to check the battery charge.

Important: The internal battery must have at least 50% charge before jump-starting a vehicle.

Battery Status LED Behaviors

During the high-temperature condition described in troubleshooting, the four flashing LEDs stop flashing after approximately 30 seconds.

Smart Jumper Cable LED Indicators and Alarm Sounds

The smart jumper cable assembly contains three status LEDs and an Override button.

Smart Cable Status and Alarm Table

The smart cable automatically resets when the condition responsible for the protection warning has been corrected.

Important Safety Instructions

Warning: Risk of electric shock, fire, and explosive gases.

Lead-acid batteries produce explosive gases during normal operation. Sparks near a battery can cause an explosion.

The jump starter must be operated according to the battery manufacturer’s instructions, the vehicle manufacturer’s instructions, and the precautions provided below.

General Electrical Safety

• Read the operating instructions before using the jump starter.
• Keep the unit away from children.
• Do not insert fingers or hands into any output connections.
• Do not expose the unit to rain or snow.
• Use only recommended cables and attachments, including the SA946 jump cable.
• Do not operate the jump starter with damaged cables or clamps.
• Disconnect power by pulling the adapter rather than the cord.
• Do not open, modify, or disassemble the unit.
• Have repairs performed by qualified service personnel using identical replacement parts.
• Do not operate a damaged or modified battery pack.
• Disconnect the charging cable before cleaning or maintenance.
• Do not expose the power pack to fire or temperatures above 265°F (130°C).
• Do not charge the unit outdoors.

Temporary outdoor use is permitted when the unit is protected from rain, snow, sleet, and similar conditions. The jump starter must be stored indoors.

Personal Safety Precautions

When working near a lead-acid vehicle battery:

1. Never smoke or allow flames or sparks near the battery or engine.
2. Remove rings, watches, bracelets, necklaces, and other metal jewelry.
3. Avoid dropping metal tools onto the battery.
4. Never allow the battery clamps to touch one another or the same piece of metal.
5. Wear appropriate eye protection and protective clothing.
6. Keep another person nearby who can provide assistance if necessary.
7. Have water, soap, and baking soda available in case of accidental contact with battery acid.
8. Keep hands away from the eyes, nose, and mouth when working around battery corrosion.

Battery Acid Safety

Vehicle battery acid contains corrosive sulfuric acid.

If battery acid contacts the skin or clothing, wash the affected area immediately with soap and water.

If acid enters the eyes, flush immediately with running water and obtain medical attention.

If battery acid is swallowed, seek medical assistance immediately and do not induce vomiting.

Battery acid spills must be neutralized thoroughly with baking soda before cleanup.

Lithium Battery Safety

The SL1672 contains a lithium-ion battery.

• Do not allow the internal battery to freeze.
• Never attempt to charge a frozen battery.
• Avoid fire and excessive heat.
• Do not use a battery pack that is damaged or altered.
• Do not restrict ventilation while charging.

In the event of a lithium battery fire, the manual identifies water, foam, CO₂, Halon, ABC dry chemical, powdered graphite, copper powder, and sodium carbonate as extinguishing agents.

The product must not be picked up or moved while it is hot, smoking, or burning. Professional emergency assistance should be obtained when the fire cannot be handled safely.

Before First Use

The internal battery should be charged immediately after purchase.

Preparing the Jump Starter

1. Inspect the unit, cables, and battery clamps for visible damage.
2. Verify that the recommended smart jumper cable is available.
3. Charge the internal battery fully before use.
4. Confirm that the vehicle uses a 12V battery system.
5. Check the vehicle manufacturer’s battery and jump-starting instructions.
6. Prepare a well-ventilated area before connecting the unit to the battery.

Preparing the Vehicle Battery

Before jump-starting:

• Verify the battery voltage in the vehicle owner’s manual.
• Clean the vehicle battery terminals if necessary.
• Avoid inhaling or touching airborne corrosion.
• Use baking soda and water to neutralize battery acid during terminal cleaning.
• Check the positive and negative battery terminal markings.
• Make sure the clamps can establish firm electrical connections.

Charging the Schumacher SL1672 Jump Starter

The internal battery should be kept fully charged to maintain jump-starting performance.

Schumacher recommends recharging:

• Immediately after purchase.
• After every use.
• Every 30 days.
• Whenever the battery charge drops below 75%.

How to Check the Battery Charge

1. Press the Power button on the front of the unit.
2. Observe the four Battery Status LEDs.
3. Compare the illuminated LEDs with the charge-level table.
4. Recharge the unit if the charge has fallen below 75%.

How to Charge the Internal Battery

1. Use an 18W USB charger for the recommended faster charging time.
2. Connect the USB-C end of the charging cable to the USB-C input on the jump starter.
3. Connect the USB-A end of the cable to the USB port of the charging adapter.
4. Plug the adapter into an active AC or DC power source.
5. Allow the internal battery to charge.
6. When all four Battery Status LEDs remain solid, the battery is fully charged.
7. Disconnect the charger from its power source.
8. Remove the charging cable from the adapter and jump starter.

Charging Time

These times are based on an 18W USB charger. A charger rated below 18W will increase the charging time.

Important: Charging must take place in a well-ventilated area within the specified charging temperature range of 32°F to 113°F (0°C to 45°C).

Connecting the Jump Starter to a Vehicle Battery

Correct battery clamp connection is essential to prevent sparks, damage, and injury.

The connection sequence depends on whether the vehicle uses a negative-ground or positive-ground electrical system.

General Connection Precautions

Before connecting the clamps:

1. Turn off the vehicle ignition.
2. Switch off electrical accessories.
3. Connect the smart jumper cable assembly to the jump starter output socket.
4. Position the cables away from moving and hot engine components.
5. Identify the positive and negative vehicle battery terminals.
6. Determine which battery terminal is connected to the vehicle chassis.

The positive battery terminal is marked POS, P, or +.

The negative battery terminal is marked NEG, N, or –.

Connecting to a Negative-Ground Vehicle

Most vehicles use a negative-ground electrical system.

1. Connect the red positive (+) clamp to the positive battery terminal.
2. Connect the black negative (-) clamp to a heavy-gauge metal part of the vehicle frame or engine block, away from the battery.
3. Make sure both connections are firm.
4. Verify that the green Ready LED becomes solid.

The black clamp must not be connected to fuel lines, the carburetor, or thin sheet-metal body components.

Connecting to a Positive-Ground Vehicle

For a vehicle with a positive-ground electrical system:

1. Connect the black negative (-) clamp to the negative, ungrounded battery terminal.
2. Connect the red positive (+) clamp to a heavy-gauge metal section of the chassis or engine block away from the battery.
3. Verify that the clamps are securely attached.
4. Check the smart cable Ready indicator.

The chassis connection must not be made to fuel lines, carburetor components, or thin sheet-metal panels.

Preventing Cable Damage

The battery cables must be kept clear of:

• Cooling fans.
• Engine belts.
• Pulleys.
• Moving engine components.
• Hot surfaces.
• Vehicle doors and hood edges.

If the vehicle hood must be closed, it must not contact the metal clamps or damage cable insulation.

How to Jump Start a Vehicle with the SL1672

The jump starter must have a minimum internal charge of 50% before starting a vehicle.

Important: The jump starter must not be operated while its internal battery is being charged. A vehicle battery must remain installed during jump-starting.

Step-by-Step Jump-Starting Instructions

1. Switch off the ignition. Turn off the vehicle engine and all electrical accessories.
2. Connect the smart jumper cable. Plug the SA946 smart cable into the jump starter’s output socket.
3. Position the cables safely. Keep them away from fans, belts, pulleys, and other moving or hot engine parts.
4. Attach the battery clamps. Follow the negative-ground or positive-ground connection procedure for the vehicle.
5. Check the Ready indicator. The green Ready LED should remain solid when the connection is correct.
6. Start the vehicle. Attempt to crank the engine.
7. Observe the starting time. If the engine does not start within 5–8 seconds, stop cranking.
8. Wait before trying again. Allow at least one minute before another starting attempt.
9. Check the indicators if starting fails. If the second attempt is unsuccessful, confirm that the green Ready LED is illuminated. Check for warning LEDs or audible alarms.
10. Disconnect after a successful start. Unplug the smart jumper cable assembly from the jump starter output socket, then remove the vehicle clamps in the appropriate sequence.
11. Recharge the jump starter. Recharge the unit as soon as possible after use.

Disconnecting the Clamps After Jump Starting

For a negative-ground vehicle:

1. Unplug the smart cable from the jump starter.
2. Remove the black negative clamp from the chassis or engine block.
3. Remove the red positive clamp from the battery terminal.

For a positive-ground vehicle, disconnect the chassis clamp first, followed by the battery terminal clamp.

Important: Do not attempt more than three consecutive jump starts. If the vehicle does not start after three attempts, consult a qualified service technician.

Automatic Smart Cable Shutoff

When no activity is detected, the smart jumper cable automatically shuts off after approximately 90 seconds.

The red Fault and green Ready LEDs remain solid when this condition occurs.

To reset the cable:

1. Disconnect the clamps from the vehicle battery.
2. Reconnect them using the correct connection procedure.

Jump Starting in Cold Weather

Cold conditions can reduce the performance of the jump starter’s lithium battery.

If the starter produces only a clicking sound and the engine does not turn over, the internal battery may need to be warmed through controlled electrical use.

Cold-Weather Starting Procedure

1. Connect the jump starter correctly to the vehicle battery.
2. Confirm that the green Ready LED is illuminated.
3. Turn on the vehicle’s lights and electrical accessories for one minute.
4. Allow the electrical load to draw current from the jump starter and warm its internal battery.
5. Attempt to start the engine.
6. If necessary, repeat the procedure within the permitted jump-start attempt limit.

Extremely cold conditions may require the battery-warming procedure two or three times before the engine starts.

Using Override Mode for a Low-Voltage Battery

When a vehicle battery has an extremely low voltage, the jump starter may not detect the battery connection.

The smart jumper cable includes an Override button for this condition.

Activating Override Mode

1. Confirm that the clamps are connected to the correct battery and chassis points.
2. Check the positive and negative connections carefully.
3. Press and hold the Override button for three seconds.
4. Release the button when the green Ready LED remains solid.
5. Proceed with the normal jump-starting instructions.

Override Mode Warning

Override mode disables a protective feature and places electrical power directly on the clamps.

The following conditions can cause serious damage:

• The clamps touching one another.
• Reversed positive and negative connections.
• Short-circuited clamp connections.
• Incorrect battery or vehicle connections.

Override mode must only be used after the battery connections have been verified.

Using the 10W Wireless Charger

The SL1672 includes a wireless charging pad that provides up to 10W of power to compatible mobile devices.

Wireless Charging Instructions

1. Confirm that the mobile device supports wireless charging.
2. Position the mobile device face-up on the wireless charging pad.
3. Press the Power button.
4. Wireless charging should begin.
5. Remove the mobile device when charging is finished.
6. Press and hold the Power button for one second to switch off the functions, or allow the unit to shut off automatically after the specified inactive period.
7. Recharge the jump starter after use.

Wireless charging compatibility should be checked against the mobile device manufacturer’s requirements.

Charging Devices Through USB-A and USB-C

The SL1672 provides two USB output ports for charging compatible mobile devices.

USB Output Specifications

USB Charging Instructions

1. Check the connected device’s charging requirements.
2. Connect the appropriate charging cable to the USB-A or USB-C output.
3. Connect the other end of the cable to the mobile device.
4. Press the Power button.
5. Allow charging to begin.
6. Disconnect the charging cable from the mobile device when finished.
7. Disconnect the cable from the jump starter.
8. Press and hold the Power button for one second to turn off the charging functions.
9. Recharge the jump starter after use.

Charging time depends on the connected device’s battery capacity and the USB charging port used.

Some compatible devices may charge more slowly than others.

Automatic USB Shutoff

If no USB device is connected, power to the USB output ports automatically shuts off after approximately 15 seconds.

Using the Built-In LED Light

The SL1672 includes an LED light with three operating modes.

Available LED Light Modes

Turning On the LED Light

1. Press and hold the Light button for two seconds.
2. Release the button after the LED light switches on.

Changing the LED Light Mode

While the light is on, press and release the Light button to move through the available modes.

The sequence includes steady illumination, SOS flashing, and strobe flashing.

Turning Off the LED Light

Press and hold the Light button until the light switches off.

Recharge the jump starter after using the LED light.

Maintenance and Cleaning Instructions

Routine maintenance helps keep the clamps, cables, and external case in suitable operating condition.

Cleaning the Jump Starter

1. Disconnect the unit after use.
2. Unplug the charging cable before cleaning or maintenance.
3. Use a dry cloth to wipe the battery clamps.
4. Remove battery corrosion, dirt, and oil from accessible external surfaces.
5. Wipe the cables and outer case with a dry cloth.

Maintenance Precautions

• Do not open the jump starter housing.
• Do not attempt internal battery replacement or repair.
• Do not perform maintenance while the charging cable is connected.
• Do not use damaged cables or clamps.
• Refer servicing to qualified repair personnel.

The jump starter contains no user-serviceable internal parts.

Storage Instructions

The internal battery should be fully charged before the jump starter is placed in storage.

Recommended Storage Conditions

Long-Term Storage

1. Fully recharge the internal battery.
2. Disconnect cables and attached devices.
3. Store the unit indoors within the recommended temperature range.
4. Do not allow the internal battery to discharge completely.
5. Recharge the unit at least once every month.
6. Recharge immediately when the battery charge drops below 75%.

Troubleshooting Guide

The following troubleshooting procedures address jump-starting, charging, and status-indicator problems.

Schumacher SL1672 Troubleshooting Table

Jump Starter Powers On but Will Not Start the Vehicle

1. Check the internal battery charge.
2. Recharge the unit if the charge is below 50%.
3. Check the smart cable connection.
4. Confirm that the green Ready LED indicates a correct connection.
5. Attempt the jump start according to the operating instructions.
6. Stop after three unsuccessful consecutive attempts.

A qualified mechanic should inspect the vehicle if the problem continues.

Jump Starter Will Not Recharge

If the unit does not charge:

1. Verify that the connected electrical outlet is active.
2. Check the power source used for the USB adapter.
3. Confirm that the charging cable is connected correctly.
4. Observe the Battery Status LEDs for charging or protection indications.

All Four LEDs Are Flashing

This condition indicates a high-temperature warning.

The manual states that the flashing stops after approximately 30 seconds.

The unit should be allowed to return to an acceptable operating temperature before use continues.

Green Ready LED Blinks After Connection

Under a particular condition, the jumper cable may detect an apparent high battery voltage without triggering reverse-charge protection.

The troubleshooting instructions identify this condition as:

• Smart cables correctly connected to the jump starter and vehicle battery.
• Green Ready LED blinking.
• Red Fault LED off.
• No audible beep.

The manual permits a jump-start attempt under this specific condition.

The battery connections and indicator state must be verified before proceeding.

Smart Cable Beeps Rapidly

Rapid beeping can indicate reversed clamp polarity or short-circuit protection.

The accompanying LED pattern identifies which protective function is active.

The condition must be corrected before restarting the operation.

The smart cable automatically resets after the relevant fault has been corrected.

Replacement Parts and Accessories

Schumacher identifies replacement parts for the smart jumper cable assembly and USB charging cable.

Replacement Parts List

The recommended smart jumper cable model is SA946.

Only recommended attachments and compatible replacement parts should be used.

Internal repair or disassembly should be performed by qualified service personnel.

Regulatory and Compliance Information

FCC Compliance

The device complies with Part 15 of the FCC rules.

Operation is subject to two conditions:

1. The device must not cause harmful interference.
2. The device must accept received interference, including interference that may result in undesired operation.

Unauthorized modifications may void the user’s authority to operate the equipment.

Industry Canada Compliance

The device also complies with applicable Industry Canada license-exempt RSS standards.

The unit must accept received interference, including interference that could affect its operation.

The manual provides FCC and Industry Canada radio-frequency exposure statements for the device.

Warranty Information

The Schumacher SL1672 is covered by a two-year limited warranty.

Warranty assistance is available through Schumacher for qualifying service, repair, and return requests.

Warranty and Service Contact

Repairs and Service

For repair services, product returns, or warranty information, contact Schumacher using the telephone number or website listed above.

Internal components must not be serviced by the user.

Qualified repair personnel should use identical replacement parts to maintain the product’s safety.

Frequently Asked Questions

1. How many amps does the Schumacher SL1672 jump starter provide?

The Schumacher SL1672 provides up to 1000 peak amps of jump-starting current. It is designed for use with compatible 12V vehicle battery systems.

2. How long does it take to charge the Schumacher SL1672?

The SL1672 takes approximately 2–3 hours to charge fully using an 18W USB charger. A charger with a lower power rating increases the charging time.

3. How much battery charge is needed to jump start a vehicle?

The jump starter must have at least 50% internal battery charge before attempting to start a vehicle. Two illuminated battery status LEDs indicate approximately 50% charge.

4. What does the green Ready LED mean on the Schumacher jump starter?

A solid green Ready LED normally indicates that the smart cable is connected correctly to both the vehicle battery and the jump starter. A blinking green LED generally indicates that the cable is connected only to the jump starter, although the troubleshooting instructions also describe a specific blinking condition with correct vehicle connections.

5. How is Override mode activated on the SL1672?

After verifying the correct battery clamp connections, press and hold the Override button on the smart jumper cable for three seconds. The solid green Ready LED indicates that the mode is active. Override mode bypasses a safety function and must be used with particular caution.

6. Can the Schumacher SL1672 charge a smartphone?

Yes. The SL1672 provides 10W wireless charging for compatible devices, as well as USB-A and USB-C charging outputs. Press the Power button to activate the charging functions.

7. Why is the Schumacher SL1672 beeping?

The smart cable uses audible alarms to indicate protection conditions. Rapid beeping with both red Fault and Clamps Reversed LEDs illuminated indicates reversed polarity. Rapid beeping with only the red Fault LED illuminated indicates short-circuit protection. One beep per second with the red Fault and green Ready LEDs illuminated indicates temperature protection.

8. How often should the Schumacher SL1672 be recharged?

Recharge the jump starter immediately after purchase, after every use, at least every 30 days, and whenever the charge falls below 75%. The unit should be stored with a fully charged internal battery.