Buzz
Which cables should connect to which terminals? And what's the correct sequence? Here are answers to your questions about using jumper cables
Your vehicle's battery might fail due to various reasons, such as cold weather draining its charge, old age, or accidentally leaving the lights on overnight. Regardless of the cause, a quick jump-start is usually sufficient to recharge it and get you back on the road. All you need is a set of jumper cables and a functional vehicle or a portable jump-start battery. We’ll guide you through the process of positioning and exposing the batteries, connecting the cables, and getting your vehicle running again.
Key Points to Remember
- Attach a red jumper cable clamp to the positive terminal of the dead battery, and the other red clamp to the positive terminal of the donor battery.
- Connect a black clamp to the negative terminal of the donor battery, and the other black clamp to an unpainted metal surface on the engine block of the dead vehicle.
- Start the donor vehicle and let it run for approximately 5 minutes, then start the dead vehicle and let it run for about 15 minutes to recharge the battery.
- Disconnect the cables in reverse order, and drive the jumped vehicle for another 15 minutes to ensure the battery is fully charged and healthy.
Step-by-Step Guide
Preparing the Vehicles
Position the vehicles so that the batteries are close to each other. Drive the vehicle with the charged battery, known as the “donor” car, towards the vehicle with the dead battery. Car batteries are typically located under the hood, so park the cars next to each other or facing each other to ensure easy access to both hoods, allowing the jumper cables to reach both batteries.
Consult the owner’s manual if you're unsure where to find the battery. The manual contains information on the battery's location and how to access it. If you don't have a physical manual, check the car manufacturer's website for a digital copy.
Engage the parking brake on both vehicles. Activating the parking brake ensures that the vehicles remain stationary during the jump-start process. If your car has an automatic transmission, shift it into “P” or “Park” to engage the brake. For manual transmission cars, shift into neutral and engage the emergency brake.
- The emergency brake is typically located near the gear stick or gas pedal.
Switch off the engines and remove the keys from both cars. Ensure that the donor car is completely turned off. Confirm by listening for the engine to shut down and checking that the radio has no power. Additionally, remove the key from the vehicle with the dead battery to prevent accidental startup when connecting the jumper cables.
- This precaution safeguards both vehicles from power surges and minimizes the risk of electrical shocks.
Scrub the battery terminals using a wire brush or similar abrasive material. Open the hood and inspect the battery terminals for any dirt, corrosion, or leaks. If you notice any white or greenish residue, use a wire brush or aluminum foil to clean it off, being careful to avoid skin contact.
- Do not attempt to jump-start batteries with physical damage, such as cracks or broken parts. Damaged batteries can present a risk of electric shock or damage to your vehicle during the jump-start process.
Identify the positive and negative terminals on each battery. The cables leading to the positive terminal are typically red, while those leading to the negative terminal are black. Look for red and black markings or symbols like “+” and “-” to indicate the terminals.
Connecting the Jumper Cables
Fasten a red clamp to the positive terminal of the dead battery. Verify the “+” and “-” labels on the battery before attaching the clamp. Press the clamp to open it, then securely position it around the metal terminal, ensuring a solid connection between the clamp and the terminal.
- On some vehicles, you may need to remove a plastic cover from the positive terminal before making the connection. Rotate the cover counterclockwise by hand or lift it off.
- Attach each clamp individually, proceeding slowly and carefully. Improperly connected jumper cables can harm your car's electrical system or cause personal injury.
Attach the other red clamp to the positive terminal of the donor battery. Take the remaining red clamp to the donor car and affix it to the positive terminal. Ensure it is firmly attached to prevent slipping during engine startup.
- Be cautious to prevent any contact between the clamps while maneuvering them, as this could lead to electric shock.
Attach a black clamp to the negative terminal of the donor battery. Take the corresponding black clamp from the donor battery and place it securely onto the black '-' terminal. Be careful not to let it touch the '+'' terminal or the red clamps.
- If you mistakenly attach a clamp incorrectly, stop immediately and remove the clamps carefully, working on one at a time to avoid contact between them.
Attach the other black clamp to an unpainted metal surface inside the car. The black clamp from the dead battery should not be connected to a battery terminal. Instead, find an unpainted metal surface at least a foot away from the battery, such as a clean bolt on the engine block. Alternatively, place the clamp on an unpainted area of the car's body under the hood.
- This clamp is grounded away from the battery to minimize the risk of a stray spark igniting the hydrogen gas present in the air when the battery is jump-started.
- Avoid digging too deeply to find a metal surface, as the fuel lines are located deeper in the engine block. Keep the clamp away from them.
- Ensure that the jumper cable does not hang into the engine compartment to prevent it from getting caught by moving parts.
Initiating the Vehicle
Start the donor vehicle and allow it to idle for a few minutes. Use the ignition key to start the engine. The electrical systems, such as lights and the radio, will activate as electricity flows to the dead battery. Wait for at least 30 seconds to allow the battery to build up power before attempting to start the other car.
- Depending on the age and condition of the dead battery, it may require additional time to charge. If the first attempt fails, let it run for another minute.
- Press the gas pedal to increase the RPM to around 3,000 to channel more power toward the dead battery.
Start the engine of the dead vehicle and let it run for 10-15 minutes. Turn the ignition key to start the car. The electrical systems should activate immediately. If the lights, radio, or other electrical components do not come on, give the battery more time—turn off the car, ensure the cables are properly attached, and then try revving the working car to boost the power supply.
- If the car fails to start after multiple attempts, it may have a different issue. Contact a mechanic, towing service, or other roadside assistance for help.
- If the car's lights come on but the engine does not start, the battery is likely fine, and the problem lies elsewhere. A clicking noise may indicate the need to replace the starter.
Reverse the sequence when disconnecting the jumper cables, starting with the black clamps. Undo the cables in the opposite order of attachment. Begin with the negative (black) grounding cable connected to a metal part on the dead car, followed by removing the black clamp from the donor battery. Then, detach the red clamp from the donor battery, and finally, remove the red clamp from the now-charged battery.
- Take the jumped car for a drive of at least 15 minutes to allow the battery to charge fully before turning off the engine.
- Exercise caution while handling the cables, ensuring that the clamps do not make contact until all of them are disconnected from the batteries.
Recommendations
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Some vehicles feature batteries located under the rear seat or in the trunk, with a jump port under the hood marked by a red cover bearing a “+” symbol. After removing the cover, attach the red jumper cable to it.
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Certain vehicles have plastic covers over the entire battery, requiring removal before attaching the cables. These covers can be pried off or unscrewed.
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Shorter cables often provide better performance as the electrical current travels a shorter distance. Longer cables may result in weaker currents and longer charging times.
Cautions
- Car batteries emit explosive hydrogen gas, so refrain from smoking near them. Also, ensure that the black grounding cable is not connected to the negative terminal on the dead battery.
- Avoid jump-starting a frozen battery, as it may explode. Check for signs of freezing by inspecting the liquid inside the battery. Additionally, if the battery appears swollen, it is likely frozen.
- Never use damaged jumper cables to start a dead battery, as this may result in electrocution.
