How to Jump Start a Car: Step-by-Step Guide for Australians

Introduction

A flat battery can happen to anyone. Whether you left the headlights on overnight, haven't driven for a while, or your battery has simply reached the end of its life, knowing how to safely jump start a car is an essential skill for every driver.

This comprehensive guide covers everything you need to know about jump starting—from preparation and proper cable connection to what to do after the engine starts. We'll also cover portable jump starters as an alternative to traditional jumper cables.

Before You Begin

Proper preparation ensures safety and success:

Safety Considerations

Car batteries contain sulphuric acid and produce hydrogen gas during charging. Taking basic precautions prevents injuries:

Remove metal jewellery (rings, watches, bracelets)

Keep cigarettes and open flames away

Wear safety glasses if available

Avoid touching terminal clamps together

Inspect Both Batteries

Before connecting anything, check both batteries for:

Cracks or leaking

Frozen electrolyte (don't jump a frozen battery)

Obvious damage or swelling

Excessive corrosion

Do not attempt to jump start if either battery appears damaged.

Verify Voltage Compatibility

Both vehicles must have the same voltage systems—typically 12 volts. Check your owner's manual if unsure. Never connect 6-volt and 12-volt systems, or 12-volt and 24-volt systems.

Equipment Needed

Jumper Cables

Quality jumper cables make the job easier and safer:

Features to look for:

Heavy gauge wire (4-6 gauge is ideal)

At least 4 metres long (longer is better)

Quality clamps with good spring tension

Insulated handles

Colour-coded (red for positive, black for negative)

Avoid:

Light gauge cables (8 gauge or higher number)

Short cables that force awkward vehicle positioning

Cheap clamps that don't grip well

Alternative: Portable Jump Starter

Modern lithium-ion jump starters are compact, reliable alternatives to cables:

Advantages:

No need for a second vehicle

Compact enough to store in the glove box

Many include USB charging ports and flashlights

Can be used safely in confined spaces

Choosing a portable starter:

Look for peak amp rating suitable for your engine size

Lithium-ion units are lighter and more reliable than lead-acid

Keep it charged—check every few months

Traditional Jump Starting: Step by Step

Follow these steps carefully for safe, successful jump starting:

1. Position the Vehicles

Park the working vehicle close enough for cables to reach both batteries

Ensure the vehicles don't touch each other

Turn off both engines

Engage parking brakes on both vehicles

Turn off lights, radio, and accessories on both vehicles

2. Identify Battery Terminals

Positive terminals are marked with + and usually have red covers or cables

Negative terminals are marked with - and usually have black covers or cables

Clean terminals with a wire brush if heavily corroded

3. Connect the Cables (This Order is Critical)

First: Connect one red clamp to the positive terminal of the flat battery Second: Connect the other red clamp to the positive terminal of the working battery Third: Connect one black clamp to the negative terminal of the working battery Fourth: Connect the other black clamp to an unpainted metal surface on the engine block of the dead vehicle (NOT to the negative terminal of the flat battery)

4. Start the Working Vehicle

Start the engine of the vehicle with the good battery

Let it run for 2-3 minutes at slightly elevated RPM (around 1500-2000)

This allows some charge to flow into the flat battery

5. Attempt to Start the Dead Vehicle

Try starting the vehicle with the flat battery

If it cranks but doesn't start, wait another few minutes and try again

If the starter clicks but engine doesn't turn, check cable connections are secure

6. If the Engine Starts

Let both engines run for a few minutes

Turn on the headlights and heater fan in the jump-started vehicle (this prevents voltage spikes when disconnecting)

7. Disconnect Cables in Reverse Order

First: Remove the black clamp from the engine block of the jump-started vehicle Second: Remove the black clamp from the negative terminal of the working vehicle Third: Remove the red clamp from the positive terminal of the working vehicle Fourth: Remove the red clamp from the positive terminal of the jump-started vehicle

8. Keep the Engine Running

After successful jump starting:

Drive the vehicle for at least 20-30 minutes to recharge the battery

Alternatively, connect a battery charger once you get home

Have the battery tested as soon as practical

Using a Portable Jump Starter

Portable units simplify the process:

1. Prepare the Unit

Ensure the jump starter is charged (check regularly when stored)

Read the manufacturer's instructions for your specific unit

Turn off the vehicle's ignition

2. Connect to Battery

Connect the red clamp to the positive terminal

Connect the black clamp to a clean metal ground point (or negative terminal, per your unit's instructions)

3. Power On and Start

Switch on the jump starter (if it has a power button)

Start the vehicle

Once started, switch off the jump starter and disconnect

4. Recharge the Unit

After use, recharge the portable jump starter promptly.

Troubleshooting

If the vehicle won't start:

No Response When Turning the Key

Check that cable clamps are making solid contact

Clean corroded terminals

Try repositioning the ground clamp

Ensure the working vehicle's engine is running

Starter Clicks But Engine Won't Turn

The flat battery may be too depleted

Let the working vehicle run for 5-10 minutes to transfer more charge

Try again

If still failing, the battery may be beyond saving or there's another problem

Engine Cranks But Won't Start

The problem may not be the battery

Check fuel level

Listen for the fuel pump

There may be another issue requiring professional diagnosis

After the Jump Start

Successfully starting the car is just the first step:

Drive to Recharge

The battery needs significant recharging after being flat:

Drive for at least 20-30 minutes

Highway driving is better than stop-start city driving

Avoid turning off the engine during short stops

Get the Battery Tested

A battery that goes flat often needs attention:

Visit an auto parts store or auto electrician for testing

Free testing is widely available

Determine if the battery can be recharged or needs replacement

Investigate the Cause

Understand why the battery went flat:

Left lights or accessories on? No action needed, just be more careful

Short trips leading to undercharging? Consider driving habits or a maintainer

Battery failing? Replace before it leaves you stranded again

Parasitic drain? Have the electrical system checked

Special Situations

Diesel Vehicles

Diesel engines require more power to start:

Use heavy-gauge cables

Let the donor vehicle run longer before attempting start

Glow plugs must warm up before starting

Modern Vehicles with Sensitive Electronics

Some newer vehicles have sensitive computers that can be affected by voltage spikes:

Consider using surge-protected cables or jump starters

Remove the key from the ignition before connecting cables

Follow your vehicle manufacturer's specific recommendations

Hybrid Vehicles

Hybrid vehicles have two batteries:

The 12V auxiliary battery can be jump started normally

Never attempt to jump start the high-voltage hybrid battery

Consult your owner's manual for specific procedures

Prevention

The best jump start is one you never need:

Have your battery tested annually

Replace batteries approaching 4-5 years old

Use a battery maintainer for infrequently driven vehicles

Turn off all lights and accessories before leaving the car

Address charging system problems promptly

Conclusion

Jump starting a car is a straightforward process when done correctly. By following proper procedures—especially the correct connection order—you can safely get a flat battery running again.

Remember that a successful jump start is often just a temporary fix. Get your battery tested and investigate why it went flat. Addressing the underlying cause prevents future roadside emergencies.