How to jump-start a car safely, step by step

By the Battery Fitment Centre workshop team · Updated 24 October 2026

What you need

• Jumper cables in good condition (thick cables with strong clamps), or a charged portable jump starter.
• A helper car with a battery of the same voltage. Almost all cars and bakkies are 12V.
• Your owner's manual. Many newer cars have special jump points under the bonnet instead of using the battery directly.

Before you start

• Park the cars close, but not touching. Both engines off, handbrakes on, in park or neutral.
• Switch off lights, radio, aircon and anything plugged in, in both cars.
• No smoking or open flames. Batteries can give off explosive gas.
• Keep the red and black clamps apart from each other at all times.

Step by step with jumper cables

1. Red clamp on the flat battery's plus (+). The plus terminal is usually marked + and often has a red cover.
2. Other red clamp on the good battery's plus (+).
3. Black clamp on the good battery's minus (−).
4. Last black clamp on bare, unpainted metal on the flat car's engine or its jump point, away from the battery and from moving parts. Not on the flat battery itself. This keeps any spark away from the battery.
5. Start the helper car and let it run for 3 to 5 minutes.
6. Start your car. If it doesn't start, wait a few more minutes and try again. Don't crank for more than 10 seconds at a time.
7. Remove the cables in reverse order: black from the engine metal, black from the good battery, red from the good battery, then red from your battery. Don't let the clamps touch.
8. Keep your engine running and drive for at least 30 minutes, or come straight to us for a free test.

Using a portable jump starter

Make sure it's charged and switched off. Connect red to plus and black to bare engine metal or the minus terminal, as the jump starter's instructions say. Switch it on, start the car, then switch it off and remove the clamps, black first.

Motorbikes, hybrids and start-stop cars

• Motorbikes: don't jump a bike from a running car. A car can push far more current than a small bike battery can handle. Use a small jump starter made for bikes, or a battery charger.
• Hybrids and electric cars: only jump using the 12V jump points shown in your manual. Never touch the orange high-voltage cables. Many hybrids should not be used to jump another car.
• Start-stop and premium cars: these often use AGM batteries and sensitive electronics. Use the jump points under the bonnet, never the battery in the boot or under a seat unless the manual says so.

When a jump start isn't the answer

A jump gets you going, but it doesn't fix the cause. If you needed a jump, have the battery and charging system tested. It's free, takes a few minutes, and tells you whether you need a charge, a new battery or an alternator check. If you're stuck, WhatsApp us your location: we can often come out to you.

This guide is general information only and doesn't replace your vehicle manufacturer's instructions. Battery Fitment Centre accepts no responsibility for damage or injury from jump-starting a vehicle. If in doubt, ask a professional.

Related: Free battery test · Car won't start? · FAQ