If you’re not fully sure how to do this, it’s safer to call roadside assistance or a mechanic rather than risk injury or damage to the car battery or electronics.

Quick safety warnings

  • Do not jumpstart if either battery is cracked, leaking, badly swollen, or heavily corroded.
  • Keep metal objects (tools, jewelry, loose clamps) away from the battery terminals.
  • Make sure both cars are in park (or neutral), parking brakes on, and ignitions off before connecting anything.
  • Never connect a cable to the negative terminal of the dead battery; use clean bare metal on the engine or chassis instead.
  • Stop immediately if cables, batteries, or connectors get very hot, smoke, or spark excessively.

What you need

  • A car with a good battery (or a jump starter pack).
  • A set of jumper cables in good condition (insulation intact, clamps clean).

Step‑by‑step: how to jumpstart a car (with another car)

1. Position the cars

  1. Park the working car close enough that the jumper cables can reach, usually nose‑to‑nose or side‑by‑side, but make sure the cars do not touch.
  1. Put both in park (automatic) or neutral (manual), set parking brakes, and shut off both ignitions.
  1. Open both hoods and locate the batteries and the + (positive) and − (negative) terminals.

Tip people use on forums: “red on dead” to remember that the red clamp first goes on the positive terminal of the dead battery.

2. Connect the cables in the correct order

Think of a 4‑step connection sequence:

  1. Red to dead – Attach one red (+) clamp to the positive terminal of the dead battery (often under a red cover with a + sign).
  1. Red to good – Attach the other red clamp to the positive terminal of the good battery.
  1. Black to good – Attach one black (−) clamp to the negative terminal of the good battery.
  1. Black to metal – Attach the last black clamp to a solid, unpainted metal part of the dead car’s engine or chassis, away from the battery (a grounding point).
  • Make sure clamps have a firm bite into metal and are not resting on plastic or paint.
  • Ensure cables are routed so they can’t get caught in fans or belts.

3. Start the cars

  1. Start the car with the good battery and let it idle for 2–5 minutes to send charge into the dead battery.
  1. Try starting the car with the dead battery.
    • If it doesn’t start, wait another 2–3 minutes and try again.
 * If it seems close, someone can gently rev the good car to around 2,000 rpm to increase alternator output.
  1. If, after several attempts and 10–15 minutes, the dead car still won’t start, the battery or another component may have failed; don’t keep cranking, get it checked.

4. Disconnect the cables (reverse order)

Once the dead car starts and idles smoothly:

  1. Remove the black clamp from the metal ground on the formerly dead car.
  1. Remove the black clamp from the negative terminal of the good battery.
  1. Remove the red clamp from the positive terminal of the good battery.
  1. Remove the red clamp from the positive terminal of the formerly dead battery.

Make sure the clamps don’t touch each other or metal bodywork while any end is still connected.

5. After the jump

  • Keep the revived car running for at least 20 minutes, ideally by driving, so the alternator can recharge the battery.
  • If it dies again soon after, the battery may no longer hold charge, or the alternator/charging system may be faulty.

Alternative: using a jump starter pack

Many newer guides recommend small lithium jump packs instead of relying on another car.

General pattern (but always follow the pack’s own manual):

  1. Turn off the car’s ignition and all accessories.
  1. Connect the pack’s red clamp to the positive terminal of the dead battery.
  1. Connect the black clamp to a clean metal ground on the car (not the negative terminal if the instructions say so).
  1. Turn on the pack if required, then try starting the car.
  1. Once the engine is running, turn off the pack and disconnect black first, then red.

Special notes (modern and electric cars)

  • Some newer cars have remote jump posts under the hood even if the battery is in the trunk; only use the marked jump points in the manual.
  • Hybrids and EVs usually have specific jump procedures and high‑voltage systems; never try to jump the main high‑voltage pack yourself.
  • For an EV with a dead 12‑volt battery, use a gas car or jump pack on the 12‑volt system only, and follow the manufacturer’s exact steps.

HTML table: basic sequence

[1][3] [5] [7][5] [3][1] [9][3] [5] [6][5]
Step Action Key details
1 Position cars safely Close but not touching; park/neutral, parking brakes on, ignitions off.
2 Identify terminals Locate + (red) and − (black) terminals on both batteries.
3 Connect cables Red to dead +, red to good +, black to good −, black to metal ground on dead car.
4 Start good car Idle 2–5 minutes to build charge in dead battery.
5 Start dead car Try starting; if needed, wait and retry, light revs of good car can help.
6 Disconnect cables Remove in reverse order: ground, good −, good +, dead +.
7 Recharge by driving Drive 20+ minutes to help recharge; if it dies again, get battery/charging system checked.

Little story to remember it

Imagine you and a friend are in a car park late at night and your car just clicks when you turn the key. Your friend pulls up nose‑to‑nose, you both pop the hoods, and you repeat the simple mantra: “red on dead, red on good, black on good, black on metal.”

You wait a couple of minutes, your friend’s engine humming, you turn the key, and your engine finally catches—then you carefully peel the cables away in reverse, both of you driving off to “recharge” what feels like both your battery and your nerves.

TL;DR: Park safely, “red on dead, red on good, black on good, black on metal,” start good car then dead car, and disconnect in reverse; if it still won’t start, the battery or charging system likely needs service.

Information gathered from public forums or data available on the internet and portrayed here.