How Long To Run Car After Jump?

Have you ever jumped into your car to start it only to realize the battery is dead? We have all been there! You are not alone. There’s nothing more annoying and unnerving than sitting in your car and hearing that clicking sound from a dead battery.

In most cases, a jump-start is all you need to start the car. But how long should you let your car run after jump-starting it? I’ll explain that in this article. But before looking at how long to keep car on after jump start, let’s see how much time it takes to charge a battery.

how long does it take to jump a car

How much time does it take to charge a car battery?

It takes 12 to 24 hours to charge a dead car battery with an actual battery charger. This is an ideal charging time with a reliable charger. However, if you decide to charge the battery with a trickle charger, it will take three or more days to charge it fully.

Generally, the charging time depends on the battery charger and the battery power output. 

The best charger rate to charge your car battery is 4 amps. It’ll take 12 to 24 hours to charge a car battery of any size from dead to fully charged. However, the battery can start your car within 1 hour of charging.

Your charger amps and battery size determine how long it’ll take to charge a dead battery to be fully charged. High amperage chargers charge your car battery faster, while low amperage gives low charging but helps in maximizing the battery life. Low amps chargers are best for battery maintenance. They help in extending your battery life span.

Here’s a list of battery charger amperes and how long it takes to charge the battery from dead to full:

  • 40 amps charger: 30 minutes to 1 hour.
  • 20 amps charger: 2 to 4 hours
  • 10 amps charger: 3 to 6 hours
  • 4 amps charger: 12 to 24 hours
  • 2 amps charger: 24 to 48 hours.

Read Also: How to Charge a Car Battery Without a Charger

How Long Should you run a car after getting a Jump?

It is best to let your car run for 30 minutes after jump-starting it because cars require half an hour to fully charge your battery or, at least, charge it sufficiently to start the car on its own.

It is recommended to get a portable jump starter kit and keep it in your emergency box. Your car battery can run down when you least expect it. The starter kit is quite affordable and can help you when you need to jump-start your car in an emergency.

However, other parameters like your charging system and battery conditions help determine the exact time to run your car after a jump-start. If you’re in a rush, you may not wait up to 30 minutes. In this case, after a car is jump-started, you should let it run for 10 to 15 minutes. After that, turn off the car and see if it will turn on without a jump-start. If it does, you can drive the vehicle without waiting any longer.

If you jump-started a car, drove 15 minutes, then it won’t start, you have charging system issues or a dead battery. 

Why do you need to run a car after getting a Jump?

Letting your car run on idle after a jump-start allows the battery to charge sufficiently to start the car on its own and prevents the car from shutting off.

The alternator, which is connected to the engine, charges the battery. As the alternator turns along with the engine pulley, the magnet inside it generates a sustainable charge. It then distributes the electric charge to all electrical components. Most importantly, it charges the battery so it can start the car.

However, vehicles don’t rely only on the alternator. The alternator and battery work in harmony in distributing electric charge to other electronics and electrical system components.

If the battery is too down, the car can shut off while driving, requiring another jump-start. Hence, it is recommended to let the car run to charge the battery before driving.

Read Also: Why My Car Battery Won’t Hold Charge?

how long to run car after jump

Some Important Tips and Tricks to Keep Your Car Battery Long-Lasting

There are several tips and tricks to keep your battery healthy. They include not leaving your car idle over a long period, avoiding short trips, minimizing power used while the engine is off, keeping the battery clean, and minimizing heat exposure.

Tighten your battery properly.

Vibration can weaken the battery’s shelf life. Hence, it is recommended to tighten the battery clamps properly to minimize vibration while driving. The vibration could damage the internal battery parts if you don’t secure the battery with clamps. This will invariably create short circuits and reduce the battery life.

Minimize the power used when the engine is off.

Car batteries work well and last longer if you maintain nearly 100% charge. Hence, playing stereos and turning on the headlight and interior lights while the car is off is a big no. Always check and turn off all your accessories when you park your vehicle.

Avoid frequent short trips.

The car draws enough power from the battery when starting it. The alternator needs to recharge the battery as you drive. The thing is, the alternator is not a fast charger like a 40 amps battery charger.

The car needs to run for a long time to replenish the power used in starting the vehicle. Since the battery needs to retain optimal charge, you are not just replacing the power used in starting the car.

Don’t leave the car unused for a long time.

My best and most common pro tip to extend your battery life is to drive and drive. All lead acid batteries discharge on their own whether connected to a car or not. This is called self-discharge.

Even if you don’t use the car often, cruise around your neighborhood for 30 minutes at least once a week. This will help extend the battery lifespan.

Regularly clean the battery terminals.

Always ensure the top of the battery is clean and free from grime, dirt, and corrosion. A corroded battery will discharge from the rusty area, leaving the battery dead over time.

Always clean the corrosion and dirt from the battery. Clean the top of the battery with a wet clean rag. Scrub the battery terminals with a washing brush or old toothbrush soaked with water and baking soda.

Minimize heat exposure

The engine bay is always hot. Please, do not add to it. Try as much as possible to minimize heat exposure. If you want to store the battery, keep it at room temperature. On the other hand, do not keep the battery on a bare floor.

Regularly check the battery lifespan.

Lead acid batteries should be kept fully charged at all times. Leaving your car battery partially or wholly discharged will shorten its shelf life.

Car batteries should maintain 12.6 volts and above. If the voltage goes below 12.5, it’ll cause issues in the long run. It is recommended to check the battery voltage with a volt meter at least once a month to ensure it stays healthy.


Can I drive immediately after the jump start?

Yes, you can drive your car immediately after a jump start, but it is best to let it run for at least 10 minutes before driving to prevent the car from shutting down along the way.

Also, can I turn off my car after a jump start? The answer is no. The vehicle will not start if you turn it off immediately after a jump start. You must let the car idle or run for a while before turning it off.

What should I do after jump-starting my car?

After jump-starting a car, allow the vehicle to run without stopping for 30 minutes. This will allow the alternator to recharge the battery sufficiently enough to start the car without a jump start. Driving the vehicle before this time can cause the car to trip off, requiring another jump-start.

Will a car battery charge while idling?

No, idling the car will not charge the car battery. Idling the car will only charge the battery a few amps to start the vehicle the next time, which is not near the hundreds of amps it took to start the engine. The battery will gradually die after a few times of starting and idling the engine.

If you need to keep the battery adequately charged, drive the vehicle long distances.

Does the revving engine charge the battery?

Revving the engine will charge the battery faster. Here’s why it is so; as the crankshaft turns faster, the alternator turns at the same speed. And the faster the alternator turns, the more it generates electricity to charge the battery.

Hey, trust me; you don’t want to be idling your car and revving the engine just to get a fast charge. You can blow up the engine.

Will a jump-start fix a dead battery?

Jump-starting your car is an effective and simple way of fixing a car that doesn’t start due to a dead battery. After jump-starting the car, the alternator will recharge the battery so it can start the car the next time you try it.

Is a car battery good after a jump?

A car battery can still last long after a jump-start if it holds a charge. Replacing your car battery because it runs down and requires a jump start is unnecessary. However, if the battery is up to five years, it’s the right time to get a new one.

Final Word

It’s essential to know how to jump-start a car, but what’s more important is knowing when to replace the car battery instead of struggling with a jump start.

Follow the tips and directives in this article to know how long to run a car after dead battery. You can also search for how long to leave a car running on Reddit to have conversations with other car owners.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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