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Do Car Batteries Charge While Idling?
Have you ever had a dead car battery and wondered if your car battery will charge back up while the car is idling? Depending on your circumstances you may need to keep your car idling until you are able to get it moving again. You may have been sitting in your car with it running thinking if your car will keep charging your car while it is currently idling.
The good news is that yes your car battery will charge when idling. Your car battery will be charged by your alternator which will provide electricity to charge the battery. Your alternator produces electricity when your car’s engine is running so as long as your car engine is on and your alternator is working properly your car battery will be charged.
How Does A Car Battery Charge?
If you are unaware of how the electrical system of your car works you may be surprised to find out how your car is able to charge your car battery. Your battery is designed to provide enough electricity to your car starter to be able to turn over your engine to allow it to fire up and start running.
Once your engine starts running it will keep running until it runs out of gasoline or there is another issue with your engine. Your engine is connected to a serpentine belt that is connected to the engine.
When your engine turns your serpentine belt, this allows the serpentine belt to power the accessories of your car to be able to provide them with electricity to function. One of the accessories that are attached to your car is called an alternator. Your alternator is ultimately in charge of charging your vehicle’s battery by providing it with electricity.
What Charges A Car Battery?
Your car’s alternator is in charge of providing electricity to the car battery to keep it charged while you drive around. The alternator is able to do this because it is an electromagnet that is driven by your serpentine belt. As your engine turns the serpentine belt will also turn which will then drive the alternator.
Your alternator should be putting out about 14-15 volts of electricity constantly while your engine is running. If your alternator is putting out less than 13 volts, then your alternator likely needs to be replaced.
You may suspect that your alternator needs to be replaced. I’ve also written an article on how much it costs to replace an alternator if you are interested in how much it may cost. It really depends on who manufactured your car and what they decided were the requirements the battery needed to meet.
Will Your Alternator Charge Your Car Battery While Idling?
Your alternator will charge your car battery if your engine is running, and your alternator is operating fine. Your engine will still turn your serpentine belt which will turn the alternator to be able to provide electricity to your car battery.
While the serpentine belt may spin faster while you have your foot on the gas its voltage is regulated by the ECU of your car. That means that your alternator should be charging your car battery at the same voltage regardless of if you are driving the car or if you currently have the car in park with the engine idling.
Will Your Alternator Work If Your Car Is Off?
If your engine is off, then it will not be spinning your serpentine belt to be able to power your alternator on your vehicle. If your alternator is not producing electricity for your car battery this means that it will not be charging the battery. The only way to charge your car battery while your car is off is via a trickle charger or other car battery charger. If you are interested in buying a car battery charger I’d recommend the Battery Tender 1.25 Amp or 750 mA version (link to Amazon.com).
Will Your Alternator Charge Your Car Battery in Neutral?
While most people won’t be sitting with their car running while in neutral you should know that your car battery will still charge if your vehicle is in neutral. Your alternator will still function properly and will provide electricity to your car battery to be able to charge it regardless of if you are in neutral. As long as you are able to get your engine started and your alternator is functioning properly your car battery should still charge in neutral.
Will Your Alternator Charge Your Car Battery in Drive?
Most people will know that your car battery will charge while you have your car in drive as that is how most people use their vehicle. If your car battery did not stay charged while you drove around this would lead to your car accessories like your radio to stop working and would ultimately lead to your engine dying. Most people know that your car battery will charge while you drive around.
How Do You Know That Your Car Battery Is Charging?
If you wanted to make sure that your car battery was charging while you had it in park you could check your car battery with a multimeter. You may or may not know that a normal car battery is a 12-volt battery. That means that the voltage of your car battery should be about 12.6 volts when your car is not running.
If you have a multimeter handy you would want to hook your black lead to the negative terminal of your battery and the red lead to the positive terminal of your battery. If you don’t own a multimeter they are fairly inexpensive and can be purchased for less than the cost of a case of beer. To check out the current prices of a multimeter that I’d recommend click here (link to Amazon.com)
You can tell if your car battery is charging by turning on your vehicle and then reading the voltage that is being produced off of the battery terminals using a multimeter. Your alternator should be putting out about 14-15 volts to be able to charge your battery. If your alternator is not putting out 14-15 volts then it may not be functioning correctly and may need to be replaced.
Do You Need to Replace Your Car Battery?
If you are having issues with your car battery charging or dying it may need to be replaced. Car batteries will typically only last about five years. If your car battery is around five years or older then it should probably be replaced as it is on the way out.
I recommend to most people that they should have a portable car jump starter just in case they go to start their car and the battery doesn’t have enough charge to get the car started. You may have jumper cables in your car but you still rely on someone to give you a jump with jumper cables. To check out a portable car jump starter I’d recommend click here (link to Amazon.com). If you are interested in a combo car jump starter and air compressor for your tires I’d recommend the STANLEY FATMAX portable power station/air compressor (link to Amazon.com).
You can read the voltage on your car battery if you wanted to get a reading for yourself. The voltage coming from the car battery while your car is off should be about 12.6 volts or above. If you read the voltage on your car battery and it has less than 12.6 volts, then you may have an issue with your charging system or battery.
What you can do if you suspect your car battery to be bad is take it to a local auto parts store to have them test it out with their battery testing device. They can hook up their battery tester to your car battery which will indicate if the battery needs to be replaced or not.
If your car battery checks out fine and it is still sitting at a low voltage, then you may need to replace your alternator. You may not know that Amazon sells car batteries but they do. You may be able to find a replacement car battery for cheaper than your local auto parts store.
Just make sure that you pick a battery that is compatible with your specific vehicle. You can do that by putting in your vehicle information into Amazon and filtering the results. If you are interested in checking out the current prices of a replacement battery for your car on Amazon click here (link to Amazon.com).
Do You Need to Replace Your Alternator?
The alternator should be putting out enough voltage to keep the battery charged while also providing electricity to the other accessories of your vehicle. If the alternator is not putting out enough voltage to the battery this can cause the voltage of the battery to remain low which can lead to your battery not having enough juice to get your car started.
You can test out your alternator by hooking up a voltmeter to your car battery while your car is idling. Your alternator should be putting out 14-15 volts to be able to adequately charge your car battery. If the alternator is putting out less voltage than that you would want to look at replacing it with another alternator. I had this happen on my current car and I ended up replacing my alternator with a used low mileage one that I bought off of eBay.
If you need to replace your alternator it’s typically not that tough of a job if you are somewhat handy with repairing vehicles. Usually, your alternator is in an easy to reach place so that you can remove it without having to remove a lot of other surrounding parts. You could also take your vehicle to a reputable mechanic to have them replace it for you.
If you wanted to watch a youtube video that shows you how to replace your alternator I’ve included a video below.
Does A Car Battery Charge While Idling? Conclusion
So then does a car battery charge while idling? You should now understand that your car will still charge its battery if the car is in idle or in park. Your vehicle is designed to be able to charge its battery while you are driving around or if you are sitting around waiting with the engine idling.
If this were not the case a lot of cops would have issues with their battery dying from sitting around idling all the time. Regardless of whatever drive mode your car is in as long as the engine is running or idling then it should be able to recharge your car battery.