How to jumpstart a car.

Everyone has heard of jumpstarting a car, but do you know how to do it safely?

Batteries are tedious, it’s often hard to pinpoint the exact issue with certainty unless you have expensive tools or vast mechanical/electrical knowledge. Often the major reason for a flat battery can be:

1. The battery is dead.
2. Headlights left on for an extended period of time.
3. Parasitic drain. (when components continue to run after the vehicle is off)
4. Alternator failing / failed.
5. Extreme temperatures.
6. Older battery.
7. Excessive short drives.

While we’re on lists here’s what you’ll need to jumpstart your car.

1. Jumper Cables – we’ve listed some to buy below
2. A power source to charge off (another car is normal, but you can use a battery box too)
3. Light of some kind, flash light or your phone is fine
4. Make sure your hazard / emergency lights are on.

So, now you know the main causes of a flat battery you can probably attribute one of them to a flat battery you’ve had in the past or you have right now..so let’s get a move on and explain how to jumpstart a car.

What you need to know about car batteries to jump start a car.

Each car battery has a positive and a negative terminal, a terminal is a little metal nub at the edge of each side of the battery. Each terminal is marked Positive and Negative with the appropriate + or – these can further be identified by red (positive) and black.(negative)  … In the image above you can see the terminal being pointed to.

So now it’s time to start the jump start process, we have broken it down in a step by step process below.

• Make sure the battery giving the jump is strong enough to actually pass power through. (6volts, 12 volts etc)
• Get both cars ready, normally parking nose-to-nose or side by side is optimal as jumper cables aren’t that long. Put the cars into park, apply the handbrake / emergency brake.
• Open the bonnet / hood of each car.
• Attach the alligator clips to the terminals (the photo above) in the following order:

• Read to dead – Connect red (or positive) to the positive terminal on the battery of the dead car.
• Red to donor – Connect the red (or positive) clip to the positive terminal on the donor batter of the other car. (the car that is working)
• Black to donor – Connect the blasck clip to the negative terminal of the donor car.
• Black to metal – This is very important, connect the black clip to an unpaired metal part of the dead car that is NOT directly next to the battery. One of the metal struts that hold the hood open is a good place for the second black clip to latch on. The image below should help explain this.
  

 

Before you go any further, just take a second to check everything is done correctly, if it’s dark make sure you have your flashlight on to go over all the connections.
START the donor car. (the car that’s working)
IDLE the donor car idle/run for a at least 30-45 seconds before doing anything else.

TEST the interior light of the car being jump started. If it turns on there may be enough power.

START the car that needs jump starting.

 

We understand some people need to read through this and understand it while they might be on the side of the road, so the above bullet point list is for them – if you are wanting a more detailed explanation we have broken it down below.

 

So, In Detail – How to Jump Start a Car

Jump starting a car is normally done from another car, the exception to this is when you get RACQ/Roadside assistance out and they will normally have a high-end battery they will use to jump your car from.

You will be connecting the two car batteries with the jumper cables, with jumper cables the rule of thumb is to buy the best you can afford. It’s often tempting to buy the cheap $15 cable but in the end those aren’t that great at transferring the power and also they are annoyingly short. Making sure the cars are at a distance that the jumper cables can safely reach, (you don’t want to stretch the cables) as we mentioned above nose-to-nose or side by side is best.

A good set of jumper cables should cost about $80-$120. If you have to buy a 15 dollar pair, just do so with the knowledge they might not work.
750 amp 12v leads (Supercheap Auto)
1000 amp  12V/24V surge protected (Australian Direct)

Look after the donor battery
You don’t want to have two broken down cars, so make sure to look after the donor battery of the car providing the jump start.
Batteries have a voltage system and it’s important to match the kind of voltage from the donor battery to the dead battery. As an example a 6V (volt) and a 12v should NOT be used together
How to tell what volt my car battery is (links to a quora article)
Now connect the alligator clips in the correct assigned order.
Making sure the donor battery isn’t low as charging can be quite taxing on the donor battery.

The order of the connection (red to dead, red to donor, black to dead, black to metal) reduces the chance of shorting the good battery.
If you want to test that the donor car has enough battery power to provide the charge is to turn the donor car off, then when turning on if your headlights are on steady and don’t cut out there should be enough power to provide the charge, if the headlights dim, cutout sportaicly that may be a sign the donor cars battery is low.

How to use jumper cables to jump start a car from another vehicle

As above this same process is recommended.

• Make sure the battery giving the jump is strong enough to actually pass power through (6volts, 12 volts etc)
• Get both cars ready, normally parking nose-to-nose or side by side is optimal as jumper cables aren’t that long. Put the cars into park, apply the handbrake / emergency brake.
• Open the bonnet / hood of each car.
• Attach the alligator clips to the terminals (the photo above) in the following order:
• Read to dead – Connect red (or positive) to the positive terminal on the batter of the dead car.
• Red to donor – Connect the red (or positive) clip to the positive terminal on the donor batter of the other car. (the car that is working)
• Black to donor – Connect the blasck clip to the negative terminal of the donor car.
• Black to metal – This is very important, connect the black clip to an unpaired metal part of the dead car that is NOT directly next to the battery. One of the metal struts that hold the hood open is a good place for the second black clip to latch on. The image below should help explain this. 

Ok, so the car is turned on – what now?

Simply reverse the order you followed to jump start the car:

1. Take the black clip off the metal it’s attached too
2. Remove the black clip from the negative terminal
3. Unclip the red clip from the donor car
4. Now remove the red clip from the dead car’s battery.

Allow the car that’s just been jump started to run without stopping for a decent amount of time, we’d recommend 10-15 minutes.

What if the jump started car doesn’t start?
If the dead car doesn’t start an you’ve followed all the above steps you can:

Check the connections are attached firmly and repeat the steps above

Once steps rechecked jump start the car again

Be careful to not jump start too many times as it may damage the working vehicles engine and electrics

Why won’t my car jump start?

There’s a large amount of reasons but some of them might be

• The jumper cables are faulty.
• The jumper cables aren’t powerful enough to transfer the required power.
• The alternator is broken and not allowing charge to be held.
• Car battery is dead.
• The battery might be out of date. (expired)
• The starter motor might be faulty or broken.
• Rare but you might have a safety switch that isn’t allowing the car to turn on.
• Lastly,  check your battery terminals to make sure there isn’t anything stopping the cables touching the metal of the terminals. 

To end this blog we also suggest having the following items in your car to cover a large range of scenarios.

A few bottles of water
Cable ties (longer is often better, nothing worse than a short cable tie)
A blanket or towel
Jumper Cable (this one probably should have been first!)
Tyre Jack and spare tyre or puncture kit.
Spanner / 4-Way Lug Wrench
Basic toolkit

If you’ve noticed your car taking longer to start than normal, or you’ve recently had a flat battery call Wayne’s Auto Repair on 3892 5543 – visit our website or email us at eric@waynesautorepairs.com.au