A flat battery is the most common cause of roadside breakdowns in Australia. Knowing how to safely jump-start your car can get you back on the road in minutes.
What You Need
- A set of jumper leads (keep them in your boot)
- A running vehicle with a charged battery
- Safety glasses (optional but recommended)
Step-by-Step Instructions
Step 1: Position the Cars
Park the working car close enough for the leads to reach, but do not let the cars touch. Turn off both engines and all electrical accessories.
Step 2: Connect the Red (Positive) Leads
Attach one red clamp to the positive (+) terminal of the dead battery. Attach the other red clamp to the positive (+) terminal of the good battery.
Step 3: Connect the Black (Negative) Leads
Attach one black clamp to the negative (-) terminal of the good battery. Attach the other black clamp to an unpainted metal surface on the dead car engine block — NOT to the dead battery negative terminal. This prevents sparks near the battery.
Step 4: Start the Working Car
Let it run for 2-3 minutes to charge the dead battery slightly.
Step 5: Start the Dead Car
Turn the key. If it does not start, wait another few minutes and try again. If it still will not start after 3 attempts, the battery may be completely dead and needs replacement.
Step 6: Disconnect in Reverse Order
Remove the black clamp from the engine block first, then the black from the good battery, then the red clamps. Drive your car for at least 20 minutes to recharge the battery.
Important Warnings
- Never connect negative to negative on the dead battery — hydrogen gas near a flat battery can ignite
- Do not jump-start a damaged, leaking, or frozen battery
- Modern cars with complex electronics may need a professional jump-start to avoid damage
If It Happens Again
A battery that goes flat once is a warning. If it happens twice, it is either failing or something is draining it. Book a battery test and electrical check at Heatherdale Automotive.