How to Check a Car Battery at Home


Dec 27, 2019

Before you commit to a VIN lookup free and a replacement car battery, have you considered testing your car battery? While a battery may appear dead, it may still be perfectly functional and capable of holding a charge. Good batteries can drain for several reasons, from human oversight to defective charging systems, which is why it is vital to check your car battery before committing to a replacement that may be unnecessary. Therefore, follow the steps below to make sure that your battery has genuinely failed.

1. Turn Off Your Car

The first step in learning how to check car battery is to turn off the power to your vehicle. However, just removing the key from the ignition is not enough. You need to make sure that all the lights are off as well. Essentially anything that can potentially be pulling current and energy from the battery will impact the test if not turned off. Once everything is off, you can move onto step two.

2. Connect the Voltmeter

With the power off, you can connect the voltmeter to the battery. When looking at your tool, you will notice a red and black lead. The red lead needs to be attached to the positive terminal on the battery. The black lead can then be connected to the negative terminal on the battery. If you accidentally switch the two leads, don’t panic. You will likely see a negative reading rather than a positive one. Simply swap the leads and recheck the reading.

3. Compare Measurements

What is reading? Do you see 12.4 volts or better? If so, then your battery is still in good shape. However, if you’re viewing a reading of 12.2 volts or less, then you may need a new battery. Although, if you get a lower reading, try to charge the battery before discarding it. A good battery can be drained and need a little boost. Check to see if the battery will hold a charge. If so, great! If not, then buy a replacement.

4. Remove the Voltmeter

You have officially finished testing your battery, so now you can remove the leads and put your voltmeter away. Start with removing the negative lead, followed by the positive lead. Sometimes the leads get stuck, and you will need a little help to remove them. However, do not use a screwdriver that may damage the battery post or internal connection. Instead, use a battery terminal puller.

5. Clean Your Battery

If your battery is holding a charge, then your car trouble could be due to a dirty battery. Find a battery terminal cleaning tool and clean the terminals and posts. These specialty tools should have several heads and extensions for different batteries.

Car batteries, like most batteries, do fail. However, there are times when a battery appears dead but is actually fully charged. Therefore, to make sure that your problem is solely the battery and nothing else, you will need to test the charge. While performing this test at home is easy enough, you can take your vehicle to an auto parts store where an employee may check your battery for free.