There are many reasons why a car battery can die, from simple reasons like leaving headlights on too long to more complicated issues like the alternator failing to charge the battery while your car is running. Whatever the reason, if you’re stranded with a dead car battery, you can either call a tow truck right away or try jump-starting your car’s dead battery with the help of another working vehicle or portable jump pack. The goal of jumping your car is to provide an electrical current from a relatively equal power source through the dead car battery. This revives the battery long enough for the car alternator to recharge it, or for you to get to an auto shop where your car’s battery can be examined or replaced.
This article will describe, step-by-step, how to safely jump start your car’s battery with the use of another person’s vehicle.
How to jump start your car’s dead battery safely:
Before You Begin:
Read the owner’s manual: Some cars are not recommended for jump starting because they have sensitive circuitry.
Check if your battery is damaged: Do not jump corroded, cracked, leaking, or visibly damaged batteries. Look for holes or cracks in the battery case; for crusty, dried leaks around the battery terminals (the metal tips you attach the jumper cables to); or for frayed wires. If you’re not sure if your battery is damaged or not, it’s better to be safe than sorry—just call a professional, you’ll probably need a tow truck.
Check if your battery is frozen: Do not jump frozen batteries. Cold weather is a common reason why car batteries don’t start, but you don’t want to jump a frozen battery as it can be dangerous. How to tell if the battery is frozen:
- if there are cracks in its case,
- if it seems to be bulging,
- if there’s no sound of liquid moving inside of it when you remove it from the engine bay.
Check if your battery is dry: Do not jump dry batteries. You can tell if a battery is dry by removing the battery port covers and shining a light into the ports. If there’s little to no water in them, jumping your battery will do more damage than good.
What do you need to jump your car?
A power source - This could be either a portable jump starter or another vehicle. If using a good samaritan’s car, be sure that neither of your vehicles have an electric ignition system or use alternate fuel, as the use of jumper cables may cause damage. Also, be sure that the voltage of both batteries are the same – a 6V battery should not be used to jump a 12V battery, and visa versa.
The “donor” car’s battery should also not be low, which you can check generally by how bright their headlights are. If they’re dim, the battery may be low and they are not a good candidate for jumping your car’s dead battery.
Jumper cables - Typically a red and black pair of cables, a few feet long with jaw-like “alligator clips” on the ends. If you don’t have these cables in your car already, check to see if the person whose car you’re using to jump has them. If no one available to you has them, you’re out of luck and you’ll need to call a tow truck to take your car to an auto shop.
WARNING: Avoid touching the jumper cable clips together. Doing so will create a sparked reaction if they are connected to a live battery, so just generally avoid touching the cable ends together. Also, make sure that your jumper cable clip handle covers aren’t cracked or missing, which would expose your skin to the electrified metal.
Where is your car battery?
On most cars, the battery is fitted under the front hood of the car and to the side of the engine, either on the right or the left. But in some car models, the battery is located in the trunk. If this is the case, there should be designated terminals under the hood for jump starting your car.
What you need to know about car batteries to jump start your car:
Car batteries have two nubs on the top, called terminals. There is a positive terminal and a negative terminal, and connecting the jumper cables to the correct terminal is important.
Positive terminal – The positive terminal is usually the bigger of the two terminals. It is marked with “POS” or “+”. It will connect to the positive clip on the jumper cable, which is usually red.
Negative terminal – The negative terminal on the battery is usually marked with “NEG” or “-“. This will attach to the other clip, which is usually black.
How to Jump Start Your Car:
IMPORTANT! Follow the steps to attach and detach the jumper cables exactly as listed. Deviating from this process can result in damage to you, your car, or your power source.
Pull up the working vehicle close to yours, nose to nose, so the jumper cables can reach between the batteries.
Place both vehicles in Park or Neutral, engage parking breaks, and shut off the ignition in both cars. Open up the hoods for both cars.
Red to Dead: Attach one of the red jumper cable clips to the positive terminal of your battery.
It has “POS” or “+” on it, or it’s bigger than the negative terminal.
Red to Donor: Attach the other red clip to the positive terminal of the other car.
Black to Donor: Attach one of the black clips to the negative terminal on the other battery.
Black to Metal: Attach the last black clip to an unpainted metal surface on your car that is not near the battery. You can use one of the metal struts that holds the hood open. Be sure that anyone close by knows not to touch this surface.
The cables should look like this:
7. Start the working (donor) vehicle and let the engine run (idle) for a few minutes.
8. Test your car’s interior lights. If they turn on, this is a good indicator that there will be enough power.
9. Try starting your vehicle.
If it won’t start, turn off the working vehicle and make sure that the cables are properly connected. Then try running the working vehicle’s engine for five more minutes, revving the working vehicle’s engine a few short times to help the battery flow, before trying to start your car again. If it still won’t start, it may be time to call a tow truck service.
10. If your car starts, do not turn it off right away.
Keep it going and drive around at least 15 minutes to give your car’s alternator time to recharge your battery. However, this may not fix the root cause of why your battery died, so you should still take it into an auto shop to be evaluated by a professional.
11. After your car is jump started and running again, you’ll need to detach the cables in the reverse order that they were connected. It’s vital that you do not let the jumper cable clips touch each other while you’re doing this.
Black from Metal
Black from Donor
Red from Donor
Red from Dead (your vehicle)
If your car battery dies again after you turn off your car, it can mean that the issue is bigger than a cold or exhausted battery. After a dead battery incident, we always recommend taking your car in for a professional battery check. If you’d like to have our expert mechanics check out your battery, you can call us at 402-932-0500 or schedule an appointment online.
Gateway Auto is a family-owned business located in Omaha, Nebraska, taking care of our customers for all their car buying, collision repair, and mechanical service needs. Book an appointment online with us or give us a call at 402-932-0500.
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