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How to Test a Car Battery: What You Need To Know!

How to Test a Car Battery: What You Need To Know!

A strong battery and fuel are the two things that your car needs to keep it running smoothly all the time. Without one or the other, your car is not going to be getting very far at all. If your battery is giving you trouble there are a number of symptoms that you can be on the lookout for to let you know that it has a problem and you may need to get it replaced. But, if you want to be sure if your battery is working properly or not, you really need to run a test on it to see if it still works well.


 

Sometimes it's easy to mistake other problems in your vehicle with a bad battery. Like we said, if you're out of gas your car isn't going to start at all, just like if your battery doesn't work. Likewise, a bad alternator has very similar symptoms to a bad battery. So, you're going to want to rule out the battery one way or the other as the source of your problem.

 

You could always take your car into a mechanic to get your battery checked to see if it's still holding a good charge, but it's just as easy to get this job done yourself if you know how to do it. Let's take a look at how exactly you test a car battery, what could cause it to give you troubles in the first place, and what you can do about it if your battery doesn't have the charge that you need to keep your car running properly.

 

How Do You Know if Your Car Needs a New Battery?

 

Obviously, you're not going to test your battery for no reason whatsoever. There should be some signs that are letting you know you may have a problem with your battery before you go out of your way to see how well it's doing. With that in mind, if you're experiencing any of these symptoms then you definitely want to test your battery to see if it's the source of the problem.

 

Battery Light: This might seem a little too obvious, but you do have an indicator light on your dashboard that will alert you to a problem with your battery. If your battery light is illuminated, then you definitely need to take it seriously and get your battery checked yet. Not every make and model will do this however and you may just get a check engine light that pops up on your dashboard. Unfortunately, the check engine light is a lot less specific than the battery light so you may not realize right away that the check engine light has anything to do with your battery if that's the reason that it came on in the first place.

 

Dimming Lights: The lights are the most noticeable part of your vehicle that rely on battery power and will therefore be one of the easiest ways to help you determine if you are having a problem with your battery or not. If the lights in your vehicle seem dim as soon as you turn your car on, that's a good indication you're having a problem with your battery. If your lights start bright and then dim after you get your car started, then that is likely a problem with your alternator rather than your battery. Still, it would be a good idea to check your battery just to be sure.

 

Clicking Sound: If your battery is in such a bad state that it can't transmit the proper power to the starter to get your car going then you're going to hear a series of clicking sounds when you try to start your car. Your engine will not be able to turn over and this very likely means that your battery is completely dead. You'll either need to get a boost from another car or replace your battery with a new one if this happens.

 

Slow Starting:  Before you get to the point of your battery failing to get your car started at all, it may just struggle to get your car started when you turn the key in the ignition. If you find yourself pressing the ignition button or turning the key and it takes a moment before the engine actually engages, it's possible that this is also a problem with your battery.

 

 If you're experiencing any of these problems, then it's probably a good idea to test your battery and see how it's doing.

 

 How Do I Test My Car Battery with a Multimeter?

 

The best way to test your car's battery is through the use of a multimeter. If you're not familiar with how to use one it can't seem somewhat intimidating at first, but once you get the hang of it it's remarkably simple and a very efficient way to get the job done. Plus, it's much more accurate than guessing how much life your battery may have in it based on how well or how poorly your electronic systems are performing.

 

 If you're not familiar, a multimeter is a tool that measures voltage. In order to use it to  test your car battery there are just a few simple steps you need to follow.

 

Step 1:  With your engine off, turn the headlights on in your car and let them stay on for about 2 minutes. This will remove any surface charge that your battery may have.

 

Step 2:  You can now turn the lights off and connect the multimeter to the positive and negative terminals of your battery. Your multimeter will have a way to change the settings on it. You're going to want to have your multimeter set to 15 to 20 volts.

 

Step 3: Check out the display on your multimeter and see where it's at.  What you want to see is 12.6 volts. If you're getting lower than that, your battery is in bad condition. If it's below 12 then your battery may not have enough power to even get your car started properly.

 

Step 4: With the multimeter still attached, start your car. The voltage should now change. If the voltage is above 10, you are looking all right. If the voltage is below 5 while your engine is running then your battery is on its last legs. You're going to want to get it replaced with a new battery as soon as you can. If you can get your car started at all with a battery that has this low of a charge, it's definitely at risk of failing anytime.

 

 Is 11.9 Volts Enough to Start a Car?

 

Once you know how to test your car battery you need to know what it means when you get a certain range of numbers. When you hook your car's battery up to a multimeter you want to be able to see something around 12.6 volts to 12.7 volts. There can of course be a little bit of wiggle room here and some car batteries will even say that, at full charge, you're going to read a voltage of about 13 volts to 13.2 volts. Typically, you only see a voltage that reaches 13 if you've recently charged the battery.

 

 A recently charged battery is something that you shouldn't be testing the voltage on because it's going to skew your numbers for you. If you’ve had to charge your battery recently let it sit for about an hour before you give it a test. If it was at 13 after a charge, there's a good chance it's going to drop back down to 12.6 volts after that hour is up. And that is generally where you want it to be.

 

The voltage of your battery can also change based on the outside temperature. On a cold day, your battery is definitely going to show a lower charge than on a warm day. So, if you're registering less than 12.6 but it is a particularly cold day it may not be cause for alarm. That said, if your voltage is showing somewhere around eleven point five or lower, even on a cold day this means that your battery has a serious problem.

 

 A battery that registers 11.5 volts has been discharged about 50%. It's going to need a charge soon if you hope to keep it working. If you continue to try to use it at this low charge, it will actually make it wear out even more quickly and become useless to you.

 

A good rule of thumb to keep in mind is that if you are reading somewhere around 11 .6 volts on your battery then it is nearly completely dead and requires a full recharge or possibly even a replacement.  If you're reading between 12.2 volt and 12.5 volts, then your battery is still functional, but it has definitely been somewhat discharged.

 

If your battery is reading 11.9 volts then, again, it may still work but it's not going to perform the way it's supposed to. At this level and below you're going to have serious performance issues with the electronic systems of your vehicle, and you risk your battery dying on you when you're out driving your vehicle.

 

 How Much Does a Car Battery Cost?

 

If you tested your battery and found that it's simply not working the way it's supposed to anymore, then you may need to head out and buy a new one. Getting the car battery is pretty easy and doesn't require really going out of your way. In fact, you can buy car batteries at all kinds of stores including places like Walmart.

 

As with most parts of a car that need replacement you have an extensive range of options when it comes to batteries. Some are definitely going to be higher quality than others so you may have to do your homework before you commit to buying anything. With that in mind, you can expect that a new car battery is probably going to cost you somewhere between $50 and $150 for your average battery. You'll likely also see some premium batteries that can cost as much as $200 or a $300 for sale as well. If that's something that you feel like is going to be important for your car then by all means you can pay that much for a battery but it's not likely you really need to spend that much. A good quality battery doesn't necessarily have to be the most expensive battery on the shelf.

 

A mechanic can easily swap your old battery for a new one, but you can save yourself some time and money by getting this job done yourself as well. It's remarkably easy to switch out an old battery for a new one and only takes a few minutes of your time to get done. If you're interested but you haven't done the job yourself before, you can head to YouTube and look for some videos that describe the process of swapping out a car battery. There are literally hundreds of them, and you could probably even find one that is specific to your make and model of vehicle if you are unsure about the whole process. Really though it's a pretty easy job and you should have no problem getting it done.

 

The Bottom Line

 

A car battery could fail for all kinds of reasons. Your average battery only has a lifespan of somewhere between 3 years and 5 years. If your battery has been in your car for over 5 years at this point, then odds are it's not going to be lasting much longer anyway. And of course, there are other reasons why a battery will cease functioning as well. Perhaps you accidentally left your lights on overnight, or maybe there is a buildup of corrosion around the terminals which is preventing your battery from transmitting power in the proper way.

 

 Whatever the case, testing your car battery will give you the answers you need as to whether your battery is still functional or whether it's best to buy a new one to get your car working properly again. Since the process is so simple, there's no reason not to make sure your battery is working as well as it can whenever you get an inclination that something may be wrong.