One of the most nerve-wracking sounds you can hear in your car is the click, click, click of attempting to start without success. There's no need to panic if you're in this scenario since the noise most likely means you have a dead battery.
The good news is that you can easily charge your car's battery on your own. Knowing how to charge a car battery will save you time, stress and money in the long run.
Learn more about the steps to successfully (and safely) charge your battery, the different types of chargers you can purchase, signs it's time for a new battery and when to seek professional help.
How To Charge Your Car Battery
Learning how to charge your car battery can seem intimidating, but it's an overall simple process. Before charging your car battery, here is an overview of what to expect:
- Difficulty level: Easy
- Supplies needed: Battery charger with connected cables and clamps, nearby electrical outlet and extension cord (if applicable)
- Expected charging time: 5 minutes to set up; 24 hours for a partial charge and overnight for a full charge
Below are step-by-step instructions to help you charge your car's battery:
1. Ensure You're Safe
Safety should always be your number one priority. Remember, when charging a car battery, you're dealing with electrical currents, and you must take proper safety precautions. This includes:
- Reading your car manual and the battery charger manual
- Removing any jewelry to prevent accidental conduction and shocks
- Keeping other electronic devices away from your charging area
- Not plugging in or starting your battery charger until after you make a stable connection
2. Identify the Battery and Prepare for Connection
Most car batteries are under the hood, and you can identify them by the positive terminal symbol (+) and negative terminal symbol (). However, in some cases, vehicle batteries are found in the trunk. There may also be a protective plastic cover over the battery terminals in both locations , if so, simply flip the cover up to connect the charger.
Double-check your owner's manual if you're having issues locating your car's battery.
3. Connect the Positive Charger
First, always connect the positive charging clamp to your car's positive terminal. The positive charging clamp is usually red and should be hooked up to the positive battery terminal, identified with the positive symbol +.
Once the clamp is attached to your battery, wiggle it a little bit to ensure there's a good connection for the electrical current to flow.
Note: The battery charger should be off and unplugged while connecting the charging clamps. For the duration of charging, keep the charger as far away from the battery as the cables allow.
4. Connect the Negative Charger
Next, connect the negative charging clamp to your car's negative terminal, identified with the negative symbol . The negative charging clamp is usually black to distinguish it from the positive one. Again, wiggle the clamp to ensure a good connection is made.
As you attach the clamp, make sure you're attaching it directly to the battery terminal and avoiding other metal parts of the car. Accidentally connecting or touching the clamp to the wrong parts can cause sparks and electrical fires.
Note: The battery charger should still be off and unplugged while connecting charging clamps, with the charger as far away from the battery as the cables allow.
5. Charge and Monitor
With both positive and negative clamps securely attached to your car's respective battery terminals, plug your battery charger in and turn it on. Once on, some chargers will automatically recognize your battery and begin charging, while others will require some manually input information.
Remember: Read the instruction manual to know how your car battery charger operates!
Chargers will often default to a lower amperage, or electrical current strength, to ensure safe and healthy charging. A low amperage ranges from 26 amps and will take several hours to fully charge your car's battery , sometimes, you must keep it charging overnight. You can purchase a car battery charger with higher amperage or increase the amount of amperage for faster charge time. However, it's important to note that high amperage can damage your car's battery life. Check your car's manual to determine the recommended amperage for your battery.
Make sure that you routinely monitor your battery's progress as it charges, checking for excessive heat and other issues.
6. Disconnect the Battery From the Charger
Some chargers will turn off automatically once they fully charge the battery, while others have a gauge to show the progress of the battery's charge and need you to turn them off manually. In either case, once your battery is charged, follow these steps to disconnect the battery from the charger:
- Start by turning off and unplugging the charger.
- Remove the black clamp from the negative () battery terminal first.
- Then, remove the red clamp from the positive (+) battery terminal.
- If applicable, close the protective plastic cover to the battery terminals.
- Move the charging clamps and battery charger away from your vehicle.
- Turn on your car to make sure the charge works.
Types of Car Battery Chargers: Choosing the Right One
Part of practicing healthy battery maintenance and learning how to charge a car battery is understanding the different types of chargers available and which one is right for you. Ultimately, the right charger for you depends on your car's battery, the type of vehicle you own and the features you deem necessary in a charger. As always, check your car's user manual for specific information.
Read on below to learn more about the differences between the two main types of battery chargers.
Automatic Battery Chargers
Automatic battery chargers prevent battery overcharging by either shutting off or moving into a low-power mode once fully charged. This feature makes them a safer option while also having less impact on your car battery's life.
Manual Battery Chargers
Manual battery chargers will charge a car's battery continuously , no matter its current charge level , and will not shut off on its own. This requires the charge to be more closely monitored and the gauge to be regularly checked to prevent overcharging and damage to your car's battery.
8 Signs You Need a New Car Battery
Once you learn how to charge a car battery, you must also know the signs you need a new car battery:
- Difficulty turning your car on in hot or cold weather.
- The check engine or battery light goes on your dashboard.
- Your car's electrical properties aren't working (e.g., rolling down windows, unlocking/locking doors, windshield wipers, phone chargers, etc.).
- You notice a smell similar to rotten eggs.
- You see evidence of corrosion (a white/blue color) around the battery.
- The car is slow to start or sputters when starting.
- Your car battery isn't holding a charge.
- Your car battery is more than 35 years old.
If you notice one or more of these signs and need a replacement, remember to recycle your car battery properly to limit environmental impacts.
When To Call Roadside Assistance
AAA members enjoy many perks and benefits with their membership. This includes access to 24/7 Roadside Assistance, where members can get help in the event of a car emergency or issue, including if you're unsure if an issue is a sign you need a new car battery.
Here are three situations when you should call Roadside Assistance:
You're Stranded
The sense of dread that can overcome you when you're out and about but suddenly your car won't start can leave you feeling helpless. With AAA Roadside Assistance, there's no need to panic. Simply make a request, and we'll send someone to your location as soon as possible!
Your Battery Is Severely Corroded
Corrosion is caused by a chemical reaction between internal battery acid and the external metals of the battery. A little bit of corrosion is normal as batteries age. However, a larger amount can be cause for concern and should prompt a call to Roadside Assistance.
Left unresolved, corrosion can signal and lead to bigger issues, such as leaking gases or battery acid, which could ultimately spark a fire.
You Suspect Other Car Problems
AAA Roadside Assistance is here to help with any car issues, whether your car won't start or your tire needs to be replaced. Requesting assistance for any suspected issue can prevent a potentially dangerous situation.
Using our Auto Repair Facilitator Locator can help you get immediate service for any suspected issue as close to your current location as possible.
Tackle Car Battery Problems With AAA
Whether you're learning how to charge a car battery for the first time, want a refresher or think you need a new battery, AAA is here to help. With your AAA Membership, you can worry less by knowing the answers to your car battery problems , and more , are just a call or click away.
Car Battery FAQ
Looking for more information related to battery tips and how to charge a car battery? See answers to some frequently asked questions below:
How Long Does It Take To Charge a Car Battery?
Charge time depends on the battery charger you use. A higher amperage battery charger will result in a faster charging time, but it can damage your battery and result in a shorter lifespan. A lower amperage (between 26 amps) will give you a full charge in a few hours and is healthier for your battery.
Does Driving a Car Charge the Battery?
In gas-powered vehicles, your alternator charges your battery as you drive. The alternator is a metal coil that works with your car's engine to create an electric current directly to the battery to stimulate a charge. A defective alternator can result in a dead car battery, so if you continue to have battery issues, consider having your alternator checked, too.
Hybrid cars have two methods of charging their battery while driving. The first is through a technique called electronically controlled breaking-regeneration, known simply as regenerative braking. Electric vehicles also use that process to charge while driving.
The second charging method for hybrids is through an internal combustion engine, where the engine triggers a generator to charge the battery while the car travels at a constant speed or when the battery is low.
Should I Clean the Battery Terminals Before Charging?
The short answer is yes! Knowing how to clean a car battery terminal is a key component of healthy car battery maintenance, which you should perform periodically. Without cleaning, your car battery becomes susceptible to corrosion , identified by its white/blueish color , which will negatively impact battery performance and lifespan.
To clean your car battery terminal, follow these steps:
- Remove the connecting cables or caps from your battery, starting with the negative () cable and then the positive (+) cable.
- Mix baking soda and water to create a paste, then apply the paste to areas with corrosion.
- Scrub the terminals with a toothbrush or similar item and rinse the residue away.
- Apply a light layer of petroleum jelly to the terminal to prevent further corrosion.
- Reattach the cables in reverse, starting with the positive (+) cable and then the negative () cable.
How Much Does AAA Charge To Replace a Car Battery?
AAA members save a minimum of $25 on car batteries. The total cost to replace a car battery depends on the make and model of your vehicle and the type of battery you're replacing.
What If My Car Battery Won't Hold a Charge After Charging?
If your car battery won't hold a charge after a couple of attempts at charging, there is likely a bigger issue with your battery or alternator. Schedule an appointment with a trusted AAA Approved Auto repair facility to have either, or in some cases, both, replaced as soon as possible.