Does Idling Charge Car Battery

Does Idling Charge Car Battery? [Check The Fact]

Idling is leaving an engine running without moving the car. Car owners are confused about whether this method charges the battery or not. So, does idling charge car battery? Let’s find out.

Idling charges the car battery if there is no issue with the alternator. It will generate enough power to supply energy to the battery from the engine. While charging the car battery through idling, it’s recommended to turn off any other electrical components.

The battery is one of the most important parts of a car. Thus, it’s always recommended to approach the proper way of charging a car battery. 

How Does Idling Charge A Car Battery?

Charging a car’s battery through idling doesn’t work in every car model. If the car’s battery is receiving more energy from the alternator than the power it’s draining because of the electrical components, then the battery will be recharged.

When the engine runs during idling, the armature of the alternator spins as it’s coupled with the engine’s crankshaft. During idling, the alternator generates a voltage between 13.5V to 14.5V. To get a battery charged, this voltage is enough. That’s how idling charges a car battery.

Idling is done when the battery is dead or weak. It’s impossible to get the battery recharged through idling for every car, as the battery of modern cars doesn’t get recharged through idling. Also, Idling is a relatively slow process of charging a battery.

Here are two recommended methods to recharge or boost your car’s battery.

2 Methods To Charge Your Car Battery: Recommended

As idling is not the recommended approach to recharge your car, here are two effective methods to charge a car battery. Try the one you find easy to apply.

1. Jumpstart

Jumpstart is basically boosting a dead battery using another car’s battery. In this method, there is only one thing required – a jumper cable. You are required to connect the jumper cable to both batteries. Check the step-by-step instructions.

Prepare The Cars: 

First, find an open space and bring both cars close to each other. You may face them towards each other to connect the cables easily. Open the car hoods.

Find The Batteries:

Locate the batteries and check for the terminals. Make sure the terminals are free of corrosion. It’s time to connect the jumper cables. Pick a quality jumper cable to continue this operation.

Connect The Cables

It’s time to connect the cables in the terminals. First the red clamps. Connect one to the positive terminal of the dead battery and the other one to the positive terminal of the good battery.

Now, connect the black clamp to the negative post on the working battery and the other black clamp to any bare metal surface on the dead battery’s car.

Start The Engine 

It’s time to power the engine of the car that has a good battery. This will boost your dead battery. Wait for a couple of minutes and try to start your car now. The battery will get charged from the good battery. 

2. Trickle Charger

A trickle charger is another effective technique to revive or charge a dead battery. Though it takes a longer time to charge a car battery through a trickle charger, the battery delivers a good hold of charge. Here are the steps to follow.

Prepare The Vehicle

To use a trickle charger, position the vehicle, as you can’t change the car’s position once the cables are connected. Turn off the ignition and remove the switch from the car.

Ground The Charger

Grounding the charger is a safety mechanism for any battery. While using the trickle charger with a car battery, you should ground it before connecting it to the battery. 

There will be a grounding clip on the trickle charger. Grounding this clip will eliminate any risk of electrical issues.

Clip The Connectors

It’s time to clip the connectors of the charger. Attach the red clip to the positive terminal and the black clip to the negative terminal. 

Switch The Charger And Check 

You now need to power the charger. Trickle charger takes a very long time to charge the car battery. So, have patience and wait till the battery gets charged. Check for any indication in the charger and keep the charger plugged in till it’s charged.


Is It Better To Idle Or Drive To Charge A Battery?

The battery of a car can be charged by either driving or idling. Driving the car is always a better option for charging the battery. This will be effective for all the components of the car.

On the other hand, idling the car will charge the battery but won’t be a good option compared with driving. Idling will recharge the battery at a very slow rate, making it tough to charge the battery completely.

Can A Car Battery Recharge Itself?

Sometimes, when you rest a dead battery, it gets recharged. This mostly happens with car batteries, as car batteries come with a ‘self-recharging’ feature.

As you know, car batteries include sulphuric acid. So, when the hydrogen gas reacts in the cell and creates blocks in the battery, it becomes dead. When you rest the same battery, the hydrogen gas will dissipate, and the battery will come back to life and get recharged again.

Does Leaving Car Idle Drain The Battery?

Leaving a car idle usually doesn’t drain the battery, but if you leave it for too long, it will start to lose charge. There is an exception in modern cars. Modern cars use alternator AC generators. This generator gives some charge at idle to prevent any charge draining while idle.

The alternators are also designed to produce a much higher charge. So, there is a quick recovery for any loss of charge.

How Long Can Your Car Idle?

To avoid any damage to the engine and the car, It’s recommended not to idle your car for more than a few minutes. If you idle your car for too long, the engine may overheat.

Also, the car engine will continue to consume fuel as long as it’s powered during the idle. If any other electrical components of the car remain powered on during the idling, there will be a loss of charge from the battery.

Final Thoughts

I guess now you know how does idling charges car battery. There will be no problem trying this method if your battery needs to charge.

However, it’s recommended to try a jumpstart or trickle charger to charge your car battery. There will not be a problem with the condition of the battery if you follow the proper way of charging a car battery.


How Long Can You Leave Your Car Running? (2021, February 3). J.D. Power. Retrieved February 20, 2023, from

Why do batteries seem to go dead and then come back to life if you let them rest? (2000, May 30). Electronics | HowStuffWorks. Retrieved February 20, 2023, from

Share the post

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *