How to Jumpstart a Car with Another Car?

Looking for how to jumpstart a car with another car? Few things are as frustrating as a dead battery when you’re in a hurry. Maybe you left the headlights on, or maybe it’s just time for a battery replacement. Whatever the cause, you’re now facing the all-too-familiar challenge of bringing that battery back to life.

Fortunately, if there’s another vehicle around with a charged battery, you’re halfway to a solution. Here’s a detailed guide on how to jumpstart a car using another car, the right way.

Step 1: Gather Your Tools

To jumpstart a car, you’ll need a set of jumper cables and a functioning car with a fully charged battery. Look for cables with heavy-duty clamps and thick insulation for the best conductivity and safety.

Pro Tip: The longer the cables, the more versatile they’ll be, especially if you’re parked in a tight spot or can’t get the cars bumper-to-bumper.

Step 2: Position the Cars

Position both cars so that they’re close enough for the cables to reach each battery. Ideally, you’ll want them parked facing each other. Keep both cars off, in park (for automatics) or neutral (for manuals), and engage the parking brakes.

Safety Note: Make sure the cars aren’t touching each other at all. Even a minor connection can interfere with the jumpstart process.

Step 3: Attach the Jumper Cables

This is the part where safety is critical. Be very deliberate when attaching each cable, and avoid letting the clamps touch one another.

1. Attach the Red Cable to the Dead Battery: Take one end of the red (positive) cable and clip it to the positive terminal of the dead battery. The positive terminal will usually have a “+” symbol or a red cap.
2. Attach the Other End of the Red Cable to the Good Battery: Now, attach the other end of the red cable to the positive terminal of the charged battery on the helper car.
3. Attach the Black Cable to the Good Battery: Connect one end of the black (negative) cable to the negative terminal on the helper car’s battery. This terminal is often marked with a “-” symbol.
4. Ground the Other Black Cable on the Dead Car: Instead of connecting the remaining black cable to the dead battery, find an unpainted metal surface on the engine block or car frame to ground it. This reduces the risk of sparks and is safer for the battery.

Step 4: Start the Helper Car

Start the car with the charged battery and let it run for a few minutes. This will allow a bit of juice to transfer to the dead battery. It may help to rev the engine slightly (to around 1,500 RPM) to produce more power from the alternator.

Wait Time: Give it around five minutes to transfer a good initial charge to the dead battery before attempting to start the other car. Patience here pays off.

Step 5: Start the Dead Car

Now, it’s time to start the car with the dead battery. Turn the ignition key to see if it cranks. If it starts, let it run for a few minutes to build up enough charge to run on its own. If it doesn’t start right away, wait a few more minutes with the helper car running before trying again.

Step 6: Disconnect the Jumper Cables in the Right Order

Once the dead car is running, carefully disconnect the cables in the reverse order of how you attached them:

1. Remove the black cable from the unpainted metal surface (ground) on the car that had the dead battery.
2. Remove the black cable from the helper car’s negative terminal.
3. Remove the red cable from the positive terminal on the helper car.
4. Remove the red cable from the positive terminal on the car that had the dead battery.

Avoid letting the clamps touch each other as you disconnect.

Step 7: Keep the Jumpstarted Car Running

To prevent another stall, keep the jumpstarted car running for at least 15-20 minutes. This allows the alternator time to recharge the battery, reducing the chance of needing another jumpstart soon.

Pro Tip: A short drive around the block can help the battery charge up faster than just idling in place.

Troubleshooting: What If the Car Still Won’t Start?

If the car with the dead battery still won’t start after a few attempts, you might be dealing with a more serious issue than a drained battery. Here are a few potential causes:

• Battery Age: If your battery is over three years old, it might be too weak to hold a charge even after a jump.
• Bad Alternator: If your car starts but dies shortly afterward, your alternator might not be keeping the battery charged.
• Corroded Battery Terminals: Rusty or corroded terminals can interfere with the connection. Use a wire brush to clean them if they’re visibly dirty.
• Damaged Cables: If the cables are worn or have exposed wiring, they may not conduct electricity effectively.

In any of these cases, it’s best to get the car checked out by a professional or consider replacing the battery if it’s near the end of its life.

Pro Tips for Jumpstarting a Car

• Invest in a Portable Jump Starter: Portable jump starters can be a lifesaver, especially if you’re stranded without another car around. These handy devices can provide enough charge to start your car without the need for a second vehicle.
• Check Your Battery Regularly: Avoid surprises by having your battery tested during routine maintenance. Most auto shops will perform a battery check as part of a standard service.
• Know the Warning Signs: Slow engine crank, dim lights, and electronics not functioning correctly can all signal a dying battery. Addressing these issues early can prevent you from needing a jump in the first place.

Final Thoughts

Jumpstarting a car with another car is a useful skill that every driver should know. While it requires attention to detail and safety, it remains a straightforward approach. By following the steps above, you’ll be able to get back on the road quickly, safely, and you’ll know just what to do next time someone else needs a jump too.