A flat battery can ruin your morning in seconds. Learning how to jump start a car is one of the most useful skills any driver can have. TowRecovery put together this guide to walk you through the process safely, whether you’re using jump leads or a portable jump starter. Keep it in mind next time your car won’t turn over on a cold morning.
What Does Jump Start Mean?
To jump start a car means giving a flat battery a boost of power from another source. This extra charge is enough to turn the engine over and get it running again. Once the engine starts, the alternator takes over and slowly recharges the battery as you drive.
When You Might Need to Jump Start a Car
Flat batteries are more common than most drivers think. Cold weather, old batteries and short journeys are usually to blame.
You may need to jump start a car if:
- The engine won’t crank when you turn the key
- Interior lights are dim or won’t switch on
- You hear clicking but the engine doesn’t start
- The car has been sitting unused for several weeks
What You’ll Need
Before you jump start a car, gather the right kit. Here’s a simple table to check you have everything.
| Item | Purpose |
| Jump leads or a battery starter jumper | Transfers power between batteries |
| Another vehicle (if using leads) | Provides the power source |
| Gloves | Protects your hands |
| Car manual | Confirms battery location and safety notes |
How to Jump Start a Car with Jump Leads
This is the traditional method and works well when another vehicle is nearby.
- Park the working car close to yours, without the vehicles touching.
- Switch off both engines and apply the handbrakes.
- Open both bonnets and locate the batteries.
- Connect the red lead to the positive terminal of the flat battery.
- Connect the other red end to the positive terminal of the working battery.
- Connect the black lead to the negative terminal of the working battery.
- Attach the final black clamp to an unpainted metal part of your engine, away from the battery.
- Start the working car and let it run for a few minutes.
- Try starting your car. If it starts, let it run for at least ten minutes.
Removing the leads should be done in reverse order once the engine is running smoothly.
How to Jump Start a Car with a Portable Jump Starter
A portable jump starter, sometimes called a battery starter jumper or a portable car jumper starter, is handy when no other vehicle is around. These compact devices work like a battery recharge pack and can sit in your boot for emergencies.
- Make sure the jump starter is fully charged before use.
- Switch off your car’s engine and open the bonnet.
- Connect the red clamp to the positive battery terminal.
- Connect the black clamp to a solid, unpainted metal point.
- Turn on the jump starter, if it has a power switch.
- Start your engine as normal.
- Disconnect the clamps once the car is running.
Most devices used to charge car batteries with jump starter functions also double as phone chargers or torches, which makes them useful to keep in your vehicle at all times.
Safety Tips When Jump Starting a Car
Safety comes first whenever you jump start a car. Follow these simple rules:
- Never let the red and black clamps touch each other.
- Keep sparks and flames away from the battery.
- Wear gloves and remove jewellery before starting.
- Check both batteries are the same voltage, usually 12V.
- Never attempt this if the battery looks swollen, cracked or leaking.
Common Mistakes to Avoid
Many drivers make small errors that cause bigger problems later.
- Connecting the clamps in the wrong order
- Leaving the engine running too briefly after a jump start
- Ignoring a battery warning light on the dashboard
- Using damaged or frayed jump leads
- Ignoring strange smells or smoke during the process
Are Jump Starters Safe?
Yes, jump starters are safe when used correctly and stored properly. Most modern devices include spark proof clamps and reverse polarity protection. Always read the manufacturer’s instructions before you jump start a car with one.
How Much Does It Cost to Jump Start a Car in Reading?
Costs vary depending on how you choose to jump start a car.
- A set of jump leads costs between £10 and £25.
- A portable jump starter typically costs £30 to £80.
- Roadside assistance call outs range from £50 to £150, depending on your provider and membership.
Keeping a portable jump starter at home is often the cheapest long term option.
FAQs
How to jump start a car with jump leads?
Connect red to red, then black to an earthed metal point, start the working car, then try your own engine.
How to jump start a car with cables?
Follow the same steps as jump leads. Attach positive to positive first, then negative to an earth point on your car.
What is the correct way to jump start a car?
Connect positive terminals first, then the negative lead to unpainted metal, never directly to the flat battery.
How much does it cost to jump start a car in the UK?
Jump leads cost around £10 to £25. Roadside assistance can cost £50 to £150 per call out.
What does jump start mean?
It means using another power source to restart a car with a flat battery.
