When it comes to car problems, nothing is comfortable. It looks like your vehicle is the perfect moment to worry you, and most of the time it's a dead battery. While it is true that the starter, alternator, or spark plugs are behind the refusal of your vehicle, it is highly likely that your battery will be zapped. In this article we will discuss how to test a car battery, especially its voltage, and also what each reading means.
Step One: Get the Right Tools
Diagnosing a car battery is a breeze, but you need a device called a multimeter. You can find a cheap one either at your local auto parts store or online. It will tell you quickly if your battery is out of juice. Although you can buy an analog multimeter, we recommend spending a little more in a digital unit so it does not misinterpret the output.
Step Two: Find the Battery
Finding your vehicle's battery should be a breeze, but some automakers place it in odd places like the trunk, under the floor or under the rear seats. However, you will find the vast majority under the hood, right or left of the engine. You can identify the battery by positive (red / plus) and negative (black / negative) terminals, which lead either to a rectangular enclosure or directly to the exposed battery. Note that in some cars the battery is hidden under a plastic cover. Read the manual if you can not find it.
Step 3: Test the battery
When you have found the device, make sure that the vehicle is off. If you are using a digital multimeter, set the dial to DC voltage. Next, take the black cable of the multimeter to the negative battery post and the red cable to the positive post. Hold each one until the multimeter provides a voltage reading.
Here are some guidelines, courtesy of yourmechanic.com:
|12.66+ Volt||100% charged|
|12.45 Volt||75% charged  12.24 Volt  50% charged|
|12.06 Volt||25% charged|
|11.89 Volt||0% charged|
If you see 12.45 volts or higher, the battery is in good shape and shape it's time to check other culprits. If you are under a 75% charge, your battery could still bring the car to life, but not reliably. Below this threshold, your battery may need to be recharged or even replaced depending on your age.
If you are having trouble with any part of this process, take a trip to your local auto parts dealer and ask for help. Most stores are happy to help you test, remove, charge and replace the car battery. You get a free hand and they will (hopefully) earn your business in the future.