The two cars are parked face-to-face, ready to jump-start.

Your vehicle battery is dead, and you need to jump-start it. Are you familiar with the proper method for jump-starting a vehicle?

Quick Tips Before You Start

  1. Always check your owner’s manual first: some vehicles have special requirements
  2. Red to positive (+), black to negative (-), or ground: never connect the final black clamp to the dead battery
  3. Turn off ALL electronics in both vehicles before connecting
  4. Drive for at least 20-30 minutes after a successful jump-start
  5. Never jump-start a frozen, cracked, or leaking battery
  6. Wear gloves and eye protection if available

At some point, almost every driver will turn their key or push the start button. They may hear a clicking sound or, even worse, complete silence. A dead battery is one of the most common vehicle problems.

This guide teaches you the safest and most effective methods to jump-start a car when you face a dead battery. Using jumper cables with another car.

A person examining a car engine while talking on phone. They are leaning over an open hood, appearing concerned while inspecting the vehicle's engine compartment, likely dealing with a breakdown or mechanical issue in a rural setting.

 

Why Do Car Batteries Die?

Car batteries typically last 3-5 years, but several common issues can cause premature failure:

  • Leaving lights or accessories on when the engine isn’t running
  • Extreme temperatures (both hot and cold weather affect battery performance)
  • Age and natural damage of the battery cells
  • A faulty alternator, not properly recharging the battery
  • Short trips that don’t allow the battery to fully recharge
  • Corrosion on battery terminals is causing poor connections
  • Damaged or loose battery cables contribute to power loss

Warning signs of a failing battery include:

  • Slow engine cranking
  • Dim headlights
  • Electrical system issues
  • The battery warning light on your dashboard

Essential Equipment for Jump-Starting

Jumper Cables

Quality jumper cables are your lifeline in a battery emergency. Look for:

  • Thickness: 4-6 gauge cables (lower numbers mean thicker cables that carry more current)
  • Length: 16-20 feet provides flexibility for positioning vehicles
  • Clamps: Strong springs with teeth that bite firmly into battery terminals

A set of automotive jumper cables showing red positive and black negative cables with metal clamps. The red cables on the left and black cables on the right are coiled and feature textured rubber handles on the alligator-style clamps, essential equipment for jump-starting a vehicle with a dead battery.

Safety Equipment

  • Gloves: To protect from battery acid and electrical shock
  • Eye protection: Shields eyes from potential battery acid splashes
  • Clean rag: For wiping corrosion from terminals before connecting

 

Before attempting to jump-start any vehicle:

  1. Check your owner’s manual for any specific instructions or cautions from the manufacturer
  2. Ensure you’re in a safe location away from traffic
  3. Verify both batteries are standard 12-volt systems (most vehicles, including hybrids, use 12V batteries)
  4. Inspect batteries for damage (cracks, leaks, bulging). Never jump-start a damaged or frozen battery
  5. Remove metal jewelry and wear eye protection if available
  6. Never lean directly over the battery when making connections
  7. Keep sparks or flames away from the battery
  8. Clean any visible corrosion from battery terminals using a brush or cloth (while wearing gloves)

Step-by-Step: Jump-Starting with Another Vehicle

Follow this sequence carefully to safely jump-start your car:

Step 1: Position the Vehicles for Jump-Start

The two cars are parked face-to-face, ready to jump-start.

  1. Park the working vehicle close enough so that jumper cables can reach both batteries
  2. Ensure vehicles are near each other but not touching
  3. Turn off both vehicles completely and remove the keys
  4. Set both transmissions to “Park” (or in gear for manual transmissions)
  5. Engage the parking brakes on both cars
  6. Turn off all lights, radio, air conditioning, and electronic accessories
  7. Open hoods and locate batteries

 

Step 2: Connect the Jumper Cables

Person holding jumper cable clamps next to a car engine. The individual in a brown jacket with striped cuffs is holding red and black jumper cable clamps with copper connectors, preparing to connect them to a vehicle battery. The open engine compartment of a white car is visible in the background, showing the setup for a battery jump-start procedure.

The connection sequence is critical for safety:

  1. First, connect the RED clamp to the POSITIVE (+) terminal of the dead battery
  2. Next, connect the other RED clamp to the POSITIVE (+) terminal of the good battery
  3. Then, connect the BLACK clamp to the NEGATIVE (-) terminal of the good battery
  4. Finally, connect the other BLACK clamp to a bare metal spot on the engine of the car with the dead battery. Do NOT connect it to the negative terminal

This final connection technique creates a ground that significantly reduces spark risk near the battery.

 

Step 3: Start the Vehicles

Close-up of a hand putting out a car key from the ignition of a vehicle's steering column.

  1. Start the working vehicle first
  2. Let it run for 2-3 minutes at a slightly increased idle
  3. Try starting your vehicle with the dead battery
  4. If it doesn’t start right away, wait another minute and try again
  5. Once your vehicle starts, let both vehicles run for a few minutes to stabilize the electrical systems

Step 4: Disconnect the Cables

Close-up of a person connecting jumper cables to a car battery. A hand in a gray sleeve is holding a red jumper cable clamp attached to the positive terminal of a car battery, while a black clamp is already connected. An orange multimeter sits on top of a nearby component, suggesting battery testing or diagnostics during the jump-start procedure.

Disconnect in the REVERSE order of connection:

  1. Remove the BLACK clamp from the metal surface of the previously dead car
  2. Remove the BLACK clamp from the negative terminal of the helper car
  3. Remove the RED clamp from the positive terminal of the helper car
  4. Remove the RED clamp from the positive terminal of your car

Step 5: Recharge Your Battery

Drive your vehicle for at least 20-30 minutes to allow the alternator to recharge the battery properly. Most vehicle alternators need at least 20 minutes of engine running time. This helps restore a good charge to a dead battery, according to Interstate Battery System of America.

Avoid turning off the engine until you’ve driven for this minimum time, or you might find yourself needing another jump-start. If your vehicle stalls shortly after jump-starting, your battery or alternator may need professional attention.