Easy Ways To Test Your Battery Voltage
Your vehicles battery is its lifeline. Without a functioning battery, youre not going anywhere. Which means you should regularly check your batterys charge to make sure it has enough juice to last you the next couple of months. Today, were going to show you an easy way to test your battery voltage.
Fortunately, this is a relatively simple task. If you have the right tools for the job, theres no reason you cant do it all by yourself.
Signs Your Car Battery Is Dying
Theres a few key warning signs that are good indications your batterys life is coming to an end. The first factor is your check engine light coming on. This usually means your battery is slowing down though it could also have to do with your vehicles alternator.Pay attention to the way your vehicle reacts when it starts as well.Its a good idea to keep an eye on the health of your battery so you dont get stranded in the middle of nowhere with a car that wont start. Here are seven telltale signs that your car battery is dying:
How To Put A New Car Battery In Your Car
While you could always have your battery replaced in the shop, itâs something you can do at home, too. If you decide to go the DIY route, there are a few things that youâll want to keep in mind. First, always check your ownerâs manual for any safety precautions that might be listed. Second, always wear gloves as battery acid can be quite harmful to the skin. Third, always disconnect your batteryâs negative terminal before the positive. Fourth, never touch a metal tool to the battery posts or terminals. Finally, be cautious of sparking both from the battery and around the battery and always wear eye protection as a precaution. With that in mind, hereâs how you change a battery:
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What Causes A Car Battery To Die Quickly
Your battery stays charged by reusing the energy created from driving. If your car sits in the driveway for long periods of time you run the risk of killing your battery. Similarly, making a lot of short trips that dont allow the battery to recharge can strain the system. And last but not least, dont forget to turn your lights off we all know how that ends!
Before We Startis The Alternator Or The Battery To Blame
If youre noticing some power issues and youre concerned about the prospect of a dying battery, you should first run a couple of tests to determine whether the issue is with the battery or the charging system before spending a good chunk of change on something you dont need.
Whats An Alternator, You Ask?
The alternator converts energy from the engine into alternating electrical current for the battery, which powers the vehicles electrical systems. So if it seems like your battery isnt working, this is the first place you should look.
You can check on the health of your alternator in a few ways:
Note: If you arent experiencing any of these symptoms, you should check your batterys voltage.
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What Should My Car Battery Voltage Be
The standard automotive battery is a 12 Volt rechargeable battery.
The resting voltage measures around 12.6V.
When the engine is running, the batterys voltage should fall between 13.7-14.7V.
But what does the voltage tell you?
Measuring the resting voltage can indicate the batterys state of charge or how much battery charge capacity remains.
In general, for a 12 Volt car battery, the state of charge is:
- 75% at 12.4V
- 25% at 12.0V
- Considered fully discharged at 11.9V
Note: If youre curious as to whether 8x 1.5V AA batteries are the same as one 12V car battery, the answer is no. AA batteries have too much internal resistance to kick start a car.
Next, lets look at a simple battery test for voltage measurements.
Check Engine Light Is On
The problem with the check engine light is that it can mean different things. It could indicate that your battery is running out of juice, or it could signal a problem with your alternator, or suggest that its time to take your car in for a tune up.
Consult your owners manual for more info and if youre still not sure, take your car to the nearest auto mechanic shop and let highly trained technicians test your battery for you.
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Related Questions And Answers
How Much is an Alternator for a Car?
If you find yourself wondering, how much is an alternator for a car, here is a quick rundown of the costs. Replacing an alternator can be fairly expensive. The total cost will depend on the vehicle you are driving, as well as if you choose a brand new, or a rebuilt alternator. If you can do the work yourself, a rebuilt alternator can cost as little as $80 for older vehicles. An alternator for a newer vehicle can run $150 to $200. If you need a professional to install your new alternator, budget between $300 and $500, depending on your car. High end sports and luxury cars will cost even more.What are the Main Components of an Alternator?
The alternator helps maintain the voltage of the car battery. There are four main components of an alternator. The stator and rotor are belt-driven magnets encased in copper wiring. They create a magnetic field. The belt is driven by a pulley that connects to the engine. This spins the rotor and creates a magnetic field. The stator uses this to create voltage and electricity which flows to the diode. The diode assembly than converts the AC electricity to DC, which is used by the car battery. Finally, the voltage regulator acts as a surge protector for the alternator.Where Can I Find Second Hand Alternators for Sale?
Car Battery Or Alternator: How To Tell Where The Problem Lies
Almost all of us have experienced the problem where either your car battery or alternator just conks out, and you can’t make out which one to replace. Its not easy finding out exactly which part of your car is giving you the trouble, but here are a few tips by which you can find out whether you have car battery problems or alternator problems.
Check Your Battery First
Check the Alternator
Test the alternator to make sure that it can start up the battery. If the battery is working properly and nothing is wrong with it, then it’s the alternator that will more likely cause a problem. A simple test to check the working of the alternator is by running your car and then unplugging the positive connection of the battery. If the car stops, then you most likely have a problem with the alternator. Another simple test is to check your interior lights. An alternator charges your battery when the car is running. If the interior and dashboard lights come on brightly but slowly start to fade, then it indicates a problem whit the alternator. It demonstrates that the alternator cannot keep a charge when the car is running. Another sign is that the car lights run brightly when you race your car, but when you slow it down, the lights start to lose power.
We also recommend that if you have a dead battery, get a jump start done and check the battery and alternator at the garage. Most garages will do this absolutely for free and it just takes about five minutes.
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Item Have Been Added To Cart
The most common temporary solution for a dead car battery is to recharge the battery using another one as a power source. The battery gets just enough power for a trip to the auto parts store. A car battery charger is designed for this purpose, but it is commonly done with jumper cables and a second car.
Follow these steps for jump starting a car battery:
- Position the car with the good battery next to the car with the dead battery. They should be close enough for the jumper cables to reach, but the vehicles should not touch each other.
- Attach the clamp of one end of the positive cable the red cable to the positive terminal of the dead battery.
- Connect the clamp of the other end of the positive cable to the positive terminal of the good battery.
- Next, clamp one end of the negative cable the black cable to the negative terminal of the good battery. Attach the other end of the negative cable to the engine block of the car with the dead battery.
- Start the car with the good battery that provides the electricity.
- Turn the ignition key of the car with the dead battery. If it starts, left the car run for about 20 minutes to allow for a recharge.
- Disconnect the jumper cables in reverse order.
Tip: Check the vehicle owner’s manual to guide you in choosing and buying a replacement battery.
Youve purchased a replacement battery. Now, follow the steps describing how to change a car battery. The first step is to make sure the vehicle is immobile.
Touch The Probes To Each Battery Terminal
Locate the positive terminal and the negative terminal on the battery.
Sometimes the battery terminal is covered with a plastic cap. Youll have to uncover the terminal to test, but you wont have to remove the battery cables.
Your battery tester will likely have a red and black probe.
First, touch the red probe to the battery positive terminal.
Then, touch the black probe to the negative battery terminal.
Note: If you get a negative reading, it means your probes are swapped, and you just need to switch the battery post theyre touching.
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Aa Battery Voltage Range
To better understand battery voltage range and capacity, you should try to understand this correlation between voltage and capacity. A cell stores up energy, while function refers to how much energy it can store. Does that make sense?
In a typical battery like the basic types, a constant voltage can be replaced with volts multiplied by the amps. Voltage is the normal parameters for a cell. Once you have chosen the energy, you can specify the capacity by the amp-hour rating.
An alkaline battery or NiMH cell in a standard AA size has something about 2000 to 3000 mAh. With a battery voltage of 1.2V up to 1.5V will correspond to 2 to 4 Wh with each battery. If you use multiple arrays in a series, the voltage rises but the capacity in the amp-hours will remain the same.
Therefore, if you will be using 3 AA battery in a series, it will give you higher voltage. If you arrange them in parallel, it will provide you with the same energy as a single cell.
Why Does A Car Battery Voltage Drop Overnight
The voltage of your car battery can drop overnight because of one of the following reasons:
The lifespan of your battery has come to an end. A parasitic drain is consuming the power of your car battery. There is a fault in the electrical system of your car.
Although finding the actual root of the problem is a DIY task, you can consult a professional if youd like to be entirely sure.
Following are some simple approaches you can take to diagnose the actual problem:
1. Visual Inspection of the Battery. Sometimes the battery doesnt hold any charge because of its poor maintenance. Disconnect your battery from its tray and check for any corrosion, bulges, and if the electrolyte level is sufficient enough. In case of a damaged battery, replace it and your problem will be solved.
2. Performing a Battery Terminal Test. Performing a simple battery terminal test will help you check if the terminals of your battery are making proper contact with the battery posts. With this test, you will get to know the voltage drop between the two.
If the voltage drop is quite high, it indicates that the charging system is not capable of providing enough charging voltage to the battery and, as a result, the battery is unable to provide enough power to the starter motor.
3. Performing Battery Voltage Tests. Battery voltage tests can be performed using a multimeter or a power probe as described in the above section. Perform those two tests to know where your battery and its charge stand exactly.
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Possible Causes Of A Dead Car Battery
The most obvious case of a dead car battery is simple user error. Either youâve inadvertently left an overhead light on, left something charging in the accessory power source, or used too much accessory power when youâve only driven a short amount. That means a lot of your batteryâs power was used when you started your vehicle, but your alternator â which returns power to your battery â didnât have enough time to fully juice your battery up.
Another potential cause of a dead car battery is age. Most car batteries utilize lead-acid, multi-cell batteries. Each cell is filled with a dilute solution of sulfuric acid as well as lead. As your vehicleâs battery ages, it undergoes a natural process called sulfation. This is when the negative plates in your carâs battery are coated in sulfate crystals, which can then build up and reduce your batteryâs ability to deliver power to your vehicle and prevent your car from starting. If your carâs battery is between 2-5 years old, this could be the culprit and it might be time for a replacement.
On occasion, a dead battery could be caused by a defect in your automobileâs battery itself. If you are repeatedly experiencing a dead battery and your vehicle or battery is new, it might be worth bringing your car into the shop to have a mechanic run a battery test to determine if it has some sort of internal defect.
Using A Car Battery Tester
Youll need a car battery testing tool called a multimeter in order to check your car battery voltage. This tool is an inexpensive and helpful addition to your garage. Once you have this tool, checking your car battery is pretty simple.
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How Do I Know I Have A Bad Battery
A bad battery can display several symptoms.
Here are some common ones:
- Engine cranking is slow: this means the battery has difficulty delivering a charge
- A misshapen battery: its bloated, cracked, or leaking
- Theres an odd smell: this can come from leaking battery acid in a lead acid battery
- Its an old battery: the average battery lifespan is around 3-5 years
If you notice any of these, its time to get a new battery.
How To Test A Car Battery For Dead Cells
Many new car batteries are of the sealed ‘maintenance’ free variety. But some older batteries allow you to access the individual cells. The cells will either have individual caps, or a plastic cover that clips over all, or some of the cells.
The cells contain a mix of water and sulphuric acid, so you don’t really want to be messing around inside them too much.
You can buy a hydrometer-style battery tester that measures the specific gravity of the battery acid, and can tell you whether any cells are ‘dead’ or not.
However knowing a cell is ‘dead’ is of no more use to you than knowing that the battery won’t hold a charge, so a test of the resting voltage is just as effective a diagnosis.
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