A dead battery is one of the most common roadside emergencies, and jumping a car is a skill every driver should have memorized. The sequence of cable connections is specific — the wrong order can cause sparks, damage electronics, or in rare cases, ignite hydrogen gas near the battery. Do it right and you’re back on the road in 15 minutes.

What You Need

Alternatively: A portable jump starter (jump pack) lets you jump your car without a second vehicle. These lithium battery packs fit in a glove box, cost $50–80, and are a worthwhile roadside kit item.

Before You Start

The Cable Color Code

Jumper cables are color-coded universally:

Connect in this specific sequence: positive first, then negative, with the last connection going to an unpainted metal ground — not the dead battery’s terminal.

Step-by-Step Connection Sequence

Connect in this order:

  1. Red clip → Dead battery positive terminal (the + terminal, usually with a red cover)
  2. Red clip (other end) → Good battery positive terminal (the + terminal on the working car)
  3. Black clip → Good battery negative terminal (the − terminal on the working car)
  4. Black clip (other end) → Unpainted metal on the dead car — an engine bracket, bolt, or metal strut away from the battery

Why not connect to the dead battery’s negative terminal? When a battery is very discharged, it can produce hydrogen gas. Connecting a cable to the terminal can create a spark near the gas. The grounded metal location keeps any sparks away from the battery.

Step 5: Start the Working Vehicle

Start the working car and let it run for 2–3 minutes. This charges the dead battery slightly before attempting to start it.

Step 6: Start the Dead Vehicle

Try to start the dead vehicle. If it starts right away, great. If not, let the working car run another 5 minutes and try again. If it doesn’t start after three attempts, the battery may be too far gone, there may be a faulty alternator, or the problem isn’t the battery.

If you hear clicking when you turn the key (but no starting), that’s typically a dead battery. If you hear nothing at all, check the connections — you may not have a good contact at one of the clamps.

Step 7: Disconnect in Reverse Order

Once the dead car has started, disconnect cables in the exact reverse order:

  1. Black clip from the dead car’s metal ground
  2. Black clip from the good car’s negative terminal
  3. Red clip from the good car’s positive terminal
  4. Red clip from the previously dead car’s positive terminal

Never let the clamps touch each other while any connection is still made.

After Jumping

Drive the jumped vehicle for at least 20–30 minutes without shutting off the engine. Driving charges the battery through the alternator. If you shut the car off immediately after jumping, the battery may be dead again.

If the battery needs jumping more than once a week, or won’t hold a charge after a long drive, it needs to be tested and likely replaced. Auto parts stores will test your battery for free. Most car batteries last 3–5 years; cold climates and frequent short trips shorten that lifespan.

Jump Packs: A Better Alternative

A portable jump starter (Noco, Tacklife, or equivalent) is a lithium battery pack that lets you jump your car alone, without a second vehicle. Connect red to positive, black to negative (both on the dead battery — jump packs are safe for direct connection), then start the car. Safer, faster, and doesn’t require waiting for assistance. Keep one in your trunk.

Memorize the sequence — Red-Red-Black-Metal — and you’ll be prepared for this emergency whenever it happens.