How to Jump Start Your Car
Learn how to safely jump start a dead battery with jump leads or a jump starter pack. Essential skill for all UK drivers.
⚠️ Critical Safety Warning
- • NEVER connect cables in the wrong order - can cause sparks, fire, or explosion
- • Both cars must have 12V batteries (check before starting)
- • Never let the jump lead clamps touch each other
- • Remove metal jewelry and keep away from moving parts
- • If battery is cracked, leaking, or frozen - DO NOT jump start, call for help
What You'll Need
- Jump leads (heavy-duty cables with clamps) - £15-30
- A donor car with a good battery (or a portable jump starter - £40-100)
- Owner's manual - some cars have specific jump start points
Step-by-Step Instructions
1. Position the Donor Car
Park the donor car close enough so the jump leads can reach both batteries, but make sure the cars are NOT touching. Put both cars in Park (automatic) or neutral (manual) with handbrakes on.
Tip: Check your handbook - some modern cars have specific jump start terminals, not direct battery access.
2. Turn Everything Off
Turn off both car engines and all electrical items (lights, radio, heater, etc.) in both cars.
3. Identify Battery Terminals
Locate the batteries in both cars. Identify the positive (+) and negative (-) terminals:
- Positive (+): Usually has a red cover or red cable
- Negative (-): Usually has a black cover or black cable
4. Connect Red Cable to Dead Battery Positive (+)
Take the RED jump lead. Attach one red clamp to the positive (+) terminal of the DEAD battery.
⚠️ Make sure the clamp is secure and making good contact with the terminal.
5. Connect Red Cable to Donor Battery Positive (+)
Attach the other end of the RED jump lead to the positive (+) terminal of the DONOR (working) battery.
6. Connect Black Cable to Donor Battery Negative (-)
Take the BLACK jump lead. Attach one black clamp to the negative (-) terminal of the DONOR (working) battery.
7. Connect Black Cable to Earth Point
Attach the other end of the BLACK jump lead to an unpainted metal surface on the dead car's engine block - NOT the battery negative terminal.
Good earth points: Engine block, metal bracket, or chassis. Check handbook for recommended point.
⚠️ DO NOT connect to the negative terminal of the dead battery - this can cause sparks near the battery.
8. Start the Donor Car
Start the donor car's engine and let it run for 2-3 minutes. This charges the dead battery slightly.
Optional: Rev the donor car gently to about 2000 RPM to help charge faster.
9. Try to Start the Dead Car
With the donor car still running, try to start the dead car. It should start within a few seconds.
If it doesn't start after 3-5 seconds, stop and wait a minute before trying again.
10. Remove Cables in REVERSE Order
Once the dead car is running, remove the jump leads in the EXACT REVERSE order you connected them:
- Remove BLACK clamp from dead car's earth point
- Remove BLACK clamp from donor battery negative (-)
- Remove RED clamp from donor battery positive (+)
- Remove RED clamp from dead battery positive (+)
⚠️ Don't let the clamps touch each other or the car body while removing them.
11. Keep the Engine Running
Keep the jumped car running for at least 20-30 minutes to recharge the battery. Don't turn it off or you might need another jump start!
Quick Reference: Connection Order
| Step | Cable | Connect To |
|---|---|---|
| 1 | RED | Dead battery POSITIVE (+) |
| 2 | RED | Donor battery POSITIVE (+) |
| 3 | BLACK | Donor battery NEGATIVE (-) |
| 4 | BLACK | Dead car EARTH point (NOT battery negative) |
Remove in REVERSE order!
⚠️ After Jump Starting
- 1. Drive for 20-30 minutes: This recharges the battery. Don't turn off the engine
- 2. If it won't start next time: Your battery may be dead and needs replacing
- 3. Get battery tested: Visit a garage to test the battery and charging system
- 4. Check alternator: If battery keeps dying, the alternator may not be charging properly
Common Reasons for Dead Battery
- •Lights left on - Headlights or interior lights draining battery overnight
- •Old battery - Car batteries last 4-5 years on average
- •Short journeys - Battery doesn't have time to fully recharge
- •Faulty alternator - Not charging the battery while driving
- •Extreme cold - Cold weather reduces battery performance
- •Car not used regularly - Battery drains over time when not used
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