If you notice the headlights on your car are dim or your engine has a slow crank, then it might be time to test your car’s battery. Knowing when and how to test a battery is crucial for maintaining your vehicle. Testing your battery regularly helps catch potential issues before they leave you stranded. Please keep reading for signs that it’s time for a test, the purpose of a battery test, and the steps to do it yourself.
Purpose of a car battery test
One reason to test your car’s battery is to avoid a situation where you get stranded on the road. It’s important to recognize the signs that your car battery could be dying. [1]
When to test a car battery
It’s recommended to test your car battery at least twice a year to catch potential issues. Because extreme temperatures can take a toll on your battery, it’s a good idea to test before the summer and winter seasons. [2]
Car battery voltage
Essentially, voltage is the electrical potential difference between two points. This is measured in volts. It can also be described as the pressure from a power source that pushes electric current through a circuit, allowing it to do work. [3]
What voltage is a car battery?
Most car batteries have a voltage of 12. More specifically, the “resting voltage” is around 12.6 volts. When the car is up and running, the voltage increases. This can range from around 13.5 to 14.5 volts when the car is running. [3]
How to test a car battery with a multimeter
When testing a car battery with a multimeter, follow these steps:
- Make sure your multimeter is set to measure DC voltage and adjusted to 20 DC volts.
- Attach the red probe to the positive terminal (marked with a “+”) and attach the black probe to the negative terminal (marked with a “-”).
- Check the reading on the multimeter. If the battery is fully charged, it should read between 12.6 and 12.8 volts.
- If your battery is showing a reading of below 12 volts. It’s a good idea to bring the car to a professional for a comprehensive test. [4]
How to test a car battery with a hydrometer
If you’re testing a car battery with a hydrometer, follow these steps:
- Turn on your headlights for about 2 minutes and then turn them off to remove any surface charge from the battery.
- Insert the hydrometer’s nozzle into one of the battery cells and squeeze the bulb to draw a sample of the electrolyte into the hydrometer’s scale.
- Evaluate the results. If the reading is between 1.265 and 1.299, it’s a healthy battery. [5]
How to test a car battery at home without tools
Testing your battery at home is a great way to ensure that it’s in good working condition. Use the following at-home methods to help determine whether your battery is corroding, dead, or in good condition. While these methods are effective for initial diagnostics, it’s crucial to recognize when it’s time to take your car to a professional.
Load testing
Load testing your car battery at home is a practical way to assess its health without needing special equipment. Follow these steps:
- Turn on your car and the headlights for about 30 seconds.
- Observe your headlights. If they are bright, this means the battery is in good condition. If they are dim, the battery might be weak or partially discharged. [6]
Car clicking noises
If you hear a series of rapid clicks when trying to start your car, this usually means the battery is dead. The noise comes from the starter trying to engage, but there isn’t enough battery current to make it start. If you hear only one or two clicks when trying to start your car, this means that the battery is too depleted to click multiple times. [7]
Online battery testing
You can use a virtual battery tester online to estimate the remaining life of your battery without needing special equipment. Simply find a virtual battery tester online, enter your car details and then you’ll receive an estimate for the battery age and conditions.
Battery corrosion
The easiest way to check for battery corrosion is to pop the hood of your car and inspect the outside of the battery. Check for any green or white flaky substances in the battery terminals — these are signs of corrosion. Other signs that the battery could be corroded are slow cranking noises, dim headlights or difficulty starting the car. [8]
Seek help from professionals to test a car battery
While testing your car battery at home can be informative, there are times when it’s necessary for some professional assistance. If you notice persistent issues despite your efforts, it’s best to take it to a professional. Maintaining a healthy battery helps ensure your car runs smoothly and prevents unexpected breakdowns. Make sure you’re fully covered on the road by getting the right auto insurance.
Sources:
[1] “How to Test Your Car Battery (and Why You Should)”, Elizabeth Yuko, lifehacker.com/travel/how-to-test-car-battery (Accessed May 2024).
[2] “A Step-by-Step Guide on How to Test a Car Battery,” Richard McCuistian, carparts.com/blog/step-by-step-guide-on-how-to-test-a-car-battery (Accessed May 2024).
[3] “What You Need to Know About Car Battery Voltage,” autozone.com/diy/battery/what-you-need-to-know-about-car-battery-voltage (Accessed May 2024).
[4] “How to Test a Car Battery with a Multimeter,” autozone.com/diy/battery/how-to-test-a-car-battery-with-a-multimeter (Accessed May 2024).
[5] “You Might Be Driving with a Dead Car Battery. Get a Battery Test.” Youssef Sleiman, interstatebatteries.com/blog/get-a-battery-test (Accessed May 2024).
[6] “How to Test a Car Battery With & Without a Multimeter,” partshawk.com/blog/how-to-test-a-car-battery-with-without-a-multimeter.html (Accessed May 2024).
[7] “Car Won’t Start & There’s a Clicking Noise?” Mia Bevacqua, carparts.com/blog/starter-solenoid-clicks-but-starter-does-not-crank-engine-2 (Accessed May 2024).
[8] “How to Check for Car Battery Corrosion,” Matt Hill, cluballiance.aaa.com/the-extra-mile/articles/prepare/car/how-to-check-for-car-battery-corrosion (Accessed May 2024).
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