7 Steps How to Use Jumper Cables Safely
Updated: Dec 23, 2020
Car batteries don't last forever, but it sucks when the battery dies at the parking lot or gas station. Luckily, it's easy to revive it if you know how to use jumper cables. When you connect them properly, these booster cables crank your vehicle using another running car's battery in around 5 minutes.
Before you rush to use jumper cables, you need to be certain that the battery is really dead or undercharged. Sometimes, corroded or loose terminal ends could be the issue. This is a small problem and can be remedied by carefully cleaning the terminals and tightening them if they're loose.
There are a host of reasons why your car battery could be dying regularly. For instance, if you come home late at night and forget to switch off the headlights or some internal lights, you'll certainly wake up to a drained battery in the morning. Your car battery may also drain due to a faulty charging system. When driving, many vehicles power the radio, lights, and other electricals using the alternator. If the alternator is faulty, for instance, due to worn out tensioners, the electricals will have to draw power from the battery, causing it to drain.
If you want to learn how to jump-start a car, this is a step-by-step guide on how to do it safely. Note that jump-starting a car carries the risk of explosions and fires. So, it's imperative that you understand and follow these steps keenly.
How to Use Jumper Cables to Start a Car Using another Car
1. Park the Vehicles Close to Each Other
The first step in jump-starting a car is to park the running vehicle next to the one with a dead battery. The need here is to park the two vehicles as close as possible so that the jumper cables can reach both batteries.
Importantly, you should ensure that the cars don't touch anywhere. This may lead to short-circuiting in the vehicles, which could cause damage to the on-board electronics. It might also cause dangerous sparks potent enough to begin a fire or cause an explosion.
On this note, if you're planning to buy a pair of jumper cables, ensure that they are at least 20 feet long. This extra length will come in handy when you can't bring the hoods of the 2 vehicles close enough, for instance, in the parking lot.
2. Locate Both Batteries and their Terminals
The location of the battery varies between different car models. In most vehicles, it's fitted under the bonnet, at the front of the engine, either on the left or the right.
After locating the battery, the next step is to access the terminals and determine their polarity (positive and negative). To distinguish the terminals' polarity, look for a positive (+) and negative (-) sign stamped somewhere on the case close to the terminals. You can also differentiate the posts by size; the positive terminal is usually larger.
3. Get Your Jumper Cables Ready
When learning how to start a battery down car, it's critical to handle the jumper cables with caution. Always beware of the fact that the red and black alligator clamps should never touch, especially after connecting one pair to the functioning battery. Doing so could cause short-circuiting, leading to expensive damage on either car.
To prevent this risk, always ensure that the positive and negative clamps are set away from each other at all times. Also, pay extra attention to step 4 of this guide on how to apply jumper cables.
4. Connect the Jumper Cables Correctly and Safely
Here is how to connect jumper cables safely when jumpstarting a car:
i) Connect one clamp of the positive (red) cable to the dead battery's positive terminal.
ii) Connect the other red clamp to the positive post of the working battery.
iii) Attach one clamp of the negative (black) cable to the negative post of the working battery.
iv) Attach the second black clamp to an unpainted metallic part on the vehicle with the dead battery. Do not attach it to the negative terminal of the dead battery. This could cause sparks that might ignite any hydrogen gas leaking from the battery.
We suggest connecting the second black camp to bare unpainted metal on the car body for extra safety. You may consider the chassis, an unpainted bolt on the engine, or even the alternator bracket. Some of the newer cars have a designated grounding point somewhere under the hood.
5. Start the Running Car's Engine
Once you're satisfied that you've connected the jumper cables correctly, turn on the engine of the car with the live battery. Let it run on idle for several minutes to allow enough electrical current to be transferred to the dead battery.
6. Attempt to Turn On the Car With the Dead Battery
After a couple of minutes, try to start the engine of the dead car. If the engine doesn't fire up immediately, you may want to try a few more times. If it springs back to life, congratulations! You've successfully jump-started the car. Don't switch off the engine, though. You'll need to leave it running as you disconnect the jumper cables. Actually, you shouldn't turn the engine off for at least 30 minutes or until you've reached your destination.
7. Carefully Disconnect the Jumper Cables
Disconnecting the jumper cables also demands a great deal of carefulness. This process is best done in the reverse order of how you connected the clamps.
Start by disconnecting the negative clamp on the vehicle that was dead, followed by the negative clamp on the donor car’s battery.
Next, disconnect the positive clamp from the donor battery’s terminal post.
Lastly, remove the positive clamp from the positive terminal of the battery that needed a jumpstart.
How long to drive after jump start?
After a successful jumpstart, ensure that you drive the vehicle for at least 30 minutes before turning off the engine. This will get enough charge to the battery so that you won’t need a jump start again.
Can a completely dead battery be recharged?
Your vehicle’s alternator is meant to keep a working battery charged, but it can’t revive a flat battery. If your battery is completely discharged, your only way out is to give it a jump start or connect it to a battery charger.
Can a car battery be too dead to jump-start?
No, unless the battery is terminally damaged, it cannot be too dead to receive a jump start. A dead or discharged battery can be revived using a portable jump starter or another working battery from a donor car.