Download ArticleDownload ArticleThis article was co-authored by Jason Shackelford. Jason Shackelford is the Owner of Stingray Auto Repair, a family owned and operated auto repair shop with locations in Seattle and Redmond, Washington. He has over 24 years of experience in auto repair and services, and every single technician on Jason’s team has more than 10 years of experience.
This article has been fact-checked, ensuring the accuracy of any cited facts and confirming the authority of its sources.
This article has been viewed 1,183,234 times.
You go to start your car only to discover that the engine won't start and the headlights won't turn on. That's a sign that it's time to check the battery. Not sure how? Don't worry—this article will walk you through how to check your car battery step by step with either a voltmeter or a power probe. If you don't have either of those things, we'll also show you how to check the battery by cranking the engine.
Steps
Get Car Support Solve Any Problem
We’re sorry we don’t support the car you are looking for. Please enter its make, model, and year below so that we can add support for it.
Turn your ignition off.[1]
Remove the battery's positive terminal cover. Check and clean the battery terminals.Advertisement- Connect your voltmeter's positive lead to the positive terminal on your battery. The positive lead on a voltmeter is usually red.[2]
- Attach the negative voltmeter lead to the negative battery terminal.
- Check the voltmeter. If your battery is in good condition, the voltage should be between 12.4 and 12.7 volts. A reading lower than 12.4 volts means that your battery needs to be charged.[3]
- If the reading is lower than 12.2 volts, "trickle charge" the battery, which is a slow charge. And then re-check.
- If the reading is over 12.9 volts, you have excessive voltage. Turn on the high beams to remove excessive voltage surface charge. Over voltage may be an indication the alternator is over charging the battery.
- While you have the voltmeter handy, you may also want to do load testing.
- Remove the battery's positive terminal cover.
- Connect your Power Probe's positive lead to the positive terminal on your battery. The positive lead on a voltmeter is usually red.
- Attach the Power Probe's negative lead to the negative battery terminal.
- Connect the tip of the probe to the positive battery terminal. Check the probe for voltage reading.
- Check the Power Probe reading. If your battery is in good condition, the voltage should be between 12.4 and 12.7 volts.[4]
- "Crank" the engine by turning the ignition until the starter engages and hold for 2 seconds Have an assistant crank the engine while you check battery voltage drop.
- At the time of the crank, check the reading of the Power Probe. It should not go below 9.6 volts.[5]
- A battery with a volt reading less than 9.6 volts means the battery is sulfated and not holding/accepting the charge.
- Alternatively, you can get the battery tested at an auto parts store or a repair shop.[6]
- They usually test your battery at no charge.[7]
- Home diagnosis is rather difficult and not very accurate.[8]
Expert Q&A
Video
Tips
- Most car batteries last between 4 and 5 years. In hot climates, they may only last about 3 years. If you charge your battery and find that it won't hold a charge while your car isn't running, replace the battery.[9]Thanks
- You can test and charge your battery at your local auto parts store.Thanks
- Before buying a new alternator, have the system checked more thoroughly.Thanks
Warnings
- Never short between battery terminals. Serious burns, damage to the terminals or an explosion from hydrogen gas can occur.Thanks
Things You'll Need
- Voltmeter
References
- ↑ https://carfromjapan.com/article/car-maintenance/how-to-test-a-car-battery/
- ↑ https://youtu.be/COJr7OB23Hw?t=87
- ↑ https://www.jdpower.com/cars/shopping-guides/how-to-test-a-car-battery-with-a-multimeter
- ↑ https://www.jdpower.com/cars/shopping-guides/how-to-test-a-car-battery-with-a-multimeter
- ↑ https://youtu.be/COJr7OB23Hw?t=35
- ↑ Jason Shackelford. Auto Technician. Expert Interview. 11 June 2019.
- ↑ Jason Shackelford. Auto Technician. Expert Interview. 11 June 2019.
- ↑ Jason Shackelford. Auto Technician. Expert Interview. 11 June 2019.
- ↑ https://www.forbes.com/wheels/advice/how-long-do-car-batteries-last/
About This Article
To check a car battery, turn off the ignition and pop your vehicle's hood. Hook up a voltmeter to the car's battery by connecting the red lead to the positive terminal and the black lead to the negative terminal. If the battery is in good condition, the voltage will read between 12.4 and 12.7 volts. A reading lower than 12.4 volts means your battery needs to be charged. If the reading is over 12.9 volts, you may want to consider having the alternator checked by a professional to figure out why this is happening! To learn more from our Master Mechanic co-author, like how to use a power probe, keep reading the article!
Reader Success Stories
"I have a basic understanding of the engine, thanks to my father, but find when dealing with service departments, it's best to research the issue first. Really like your site, easy to understand and visual aides are very helpful. Will use again. Thank you!!"..." more
Did this article help you?
⚠️ Disclaimer:
Content from Wiki How English language website. Text is available under the Creative Commons Attribution-Share Alike License; additional terms may apply.
Wiki How does not encourage the violation of any laws, and cannot be responsible for any violations of such laws, should you link to this domain, or use, reproduce, or republish the information contained herein.
- - A few of these subjects are frequently censored by educational, governmental, corporate, parental and other filtering schemes.
- - Some articles may contain names, images, artworks or descriptions of events that some cultures restrict access to
- - Please note: Wiki How does not give you opinion about the law, or advice about medical. If you need specific advice (for example, medical, legal, financial or risk management), please seek a professional who is licensed or knowledgeable in that area.
- - Readers should not judge the importance of topics based on their coverage on Wiki How, nor think a topic is important just because it is the subject of a Wiki article.
