When To Replace Your Car Battery
While a low meter reading is a strong indicator of battery distress, a drained batteryperhaps the result of lights being left on for several hours after turning your vehicle offcould lower the readout as well. Moreover, if youre running many accessories at the same time, that will drain the battery as well.
To remedy a weak battery, simply run cables from the distressed battery to a strong one. Keep the batteries connected for a few minutes to ensure enough power is transferred, and then use the voltmeter to gauge the batterys strength. If it remains weak, then it may be time to replace your car battery.
Check out all the car batteries available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on voltage of a car battery, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Pixabay.
Can A Battery Be Bad If It Reads 12 Volts
If the battery cannot reach higher than 10.5 volts when being charged, then the battery has a dead cell. If the battery is fully charged but the voltage is 12.5 or less, the battery is sulfated. If your battery cannot even reach a full charge, consider it bad.
Rely On Jiffy Lube To Keep You Rolling
Preventive maintenance, performed by highly-trained technicians, can help save you two of your most valuable resources:
- Time. Commuting to work, carpooling to school, grocery shopping you need your car! Preventive maintenance can help you avoid a major repair that could keep your vehicle off the road and in the shop for days .
- Money. Catching a small problem when it’s still a simple fix can save you the cost of an expensive repair.
Don’t Miss: Smoke Detector Beeping After Battery Change
What Is The Difference Between Different Car Battery Voltages
There are three major car battery voltages: deep cycle, starter and automotive. Each of these has particular requirements, but many similarities exist among them. The standard output voltage for an automobile battery is 12 volts . Car batteries use the same basic components to power the car, but they can be charged in different ways and at different voltages.
Types of batteries
The Minimum Safe Voltage Of The Car Battery
All of the time the battery will not hold full capacity. With usage its voltage will drop over time, this is because the battery is losing its charge holding capacity. This will lead the battery to the time when it will not be able to crank start the car and to know the voltage is the best way to stay safe from any difficult situations.
When you measure the voltage of your car battery and it gives values near 9.6 volts, this means that the battery needs to be changed. If the voltage reading is below 9.6 volts, it means that the battery is not now safe to use and you must replace it as soon as possible.
Knowing about the voltage of the car battery can keep you safe from many difficult situations. It is better to keep track of the voltage of your car battery. That is why we shared some important and easy checks for your car battery voltage.
Recommended Reading: Battery Replacement Ford Key Fob
How To Interpret Your Multimeter Reading
If your battery has a charge between 12.4V and 12.7V, your battery is fully charged and ready to run. If your voltage is below 12.2V, it needs to be recharged. Take a 30-minute drive on the highway or pick up a to bring the voltage back up. If your voltage is higher than 12.9V, the battery is overcharged. Overcharging can damage a battery, so you’ll want to remove some of that excess current. You can do this by switching your headlights on the high beam setting for a short time and then testing your battery again to make sure it’s in the ideal range.
How Do You Measure The State Of Charge
There are a few ways in which you can understand the SOC. You can:
Track the flow of the unit with a shunt and the relevant metering circuit.
Use a hydrometer to measure the chemistry
Use a voltmeter to measure the voltage
When measuring, to get the best results, make sure that the circuit is at rest or resting. Do not carry out these tests if the battery-pack is charging or under load. Ideally, you should leave the unit in a resting state for an hour before carrying out your measurements. If the circuit you are reading is connected to solar panels, make sure that you take the reading when the sun isnt hitting them otherwise, the unit will be charging, and the reading will not be accurate.
Recommended Reading: Duralast Gold Battery 35 Dlg Group Size 35 640 Cca
How To Check Your Car Battery Voltage
You dont need to be a mechanic to test your car battery voltage in Slidell, Picayune, or St. Tammany Parish. You just need to read this quick guide from your friends at Honda of Slidell.
Following these steps on a regular basis can help you discover battery problems before you end up stranded somewhere. Read on to learn how to check your car battery voltage both with and without a multimeter and with any questions!
Minimum Voltage To Start A Car
As stated above, the minimum voltage to start a car is regarded as being 10.8 volts. Anything below that and you may or may not be able to start the car, depending on the load your vehicle is receiving in attempting to start the car. This load is different for every vehicle welcome to the engineering world.
All in all, keep your voltage as close to 12 volts as possible and you wont have to worry about minimum voltages.
This article is accurate and true to the best of the authors knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Recommended Reading: Best Battery Backup For Sump Pump
Check Battery Voltage And State Of Charge
The first things you want to check are the battery and the output of the charging system . One way to do this is to turn on the headlights. If the headlights come on with normal brightness, the no-crank problem is probably not the battery, but a bad starter relay or solenoid, a poor wiring connection between the relay/solenoid and starter, or a bad starter. If the headlights are dim or do not come on at all, you need to check battery voltage and charging output.
For this, you will need a voltmeter. Select the 12 or 20 volt scale, and connect the volt meter red positive test lead to the battery positive terminal, and the black negative test lead to the battery negative terminal.
Checking base battery voltage with a voltmeter.
A fully charged battery should read over 12.6 volts. If the battery reads 12.45 volts or less, it is low and needs to be recharged.
How Do You Measure Your Car Battery’s Voltage
You can measure your battery’s voltage using a handheld tool called a multimeter. Just follow these simple steps.
Don’t Miss: Ring Spotlight Cam Battery Hd Security Camera
How To Test A Car Battery With A Multimeter
When your car doesnt start, often a low or dead battery is the culprit. Unfortunately, most vehicle owners do not check their battery until it fails. As preventative maintenance, the suggested best practice is to conduct a car battery voltage test regularly at least twice per year using a multimeter.
A multimeter is an electronic measuring instrument that is used to gauge volts, amps, and resistance from an electrical source. The most common automotive application for a multimeter is to test the strength of a car battery. When used properly, it will provide voltage information to a high degree of accuracy on a digital readout. Understanding the data provided is vital in determining whether the battery is strong and healthy or should be replaced.
How Much Voltage Drop Is Acceptable
Voltage drop should happen too slow to notice any difference overnight. As voltage drop is a natural mechanism that takes place when producing electricity, it is inevitable.
But how much voltage drop is acceptable? Should it be noticeable overnight? The answer is no. It should not be noticeable over the span of a few days let alone a night. The difference in voltage should appear to be noticeable over the weeks.
If you notice such a fast drop in voltage, you can assume something is wrong. It can either be the wiring, electrical equipment, or the battery. In case there is a noticeable drop within a night or a span of 2-3 days you should take your car to a professional.
Read Also: When Should I Change My Car Battery
How To Measure Key
Any of the follogin methods can be used to measure key-off current drain on the battery:
Check for Voltage Drop: Use a digital volt meter to measure voltage drop across individual fuses with the key off. This method does not require removing any fuses or disconnecting the battery. Set the voltmeter to the millivolt scale. No current flow through a circuit should show a zero reading on the voltmeter when the probes are connected to both sides of individual fuses. Any reading other than zero would indicate current flow in a circuit and a potential drain on the battery.Use an ammeter with an amp probe to measure key-off current flow at the battery: Connect an inductive amp probe to your ammeter or digital multimeter, then clamp the probe around one of the battery cables. Set the meter to read milliamps . If there is a key-off current drain on the battery, the meter should detect the current. Make sure the amp probe you are using is one that is calibrated to detect small milliamp currents, not large multiamp currents.Use an ammeter to measure key-off current flow at the battery: This method requires disconnecting one of the battery cables and connecting the ammeter in series between the battery and cable so any current flow will pass through the meter. Make sure you provide backup power to the electrical system before disconnecting the battery. As before, use the milliamp scale.
Shop By Ah From Batteryspecialistca
- Now:$16.99Was: Our maintenance-free sealed lead acid batteries with absorbed glass mat technology offer outstanding performance withstanding high current output and deep cycling. Excellent resistance to vibration, shock, chemicals and heat. Lower self-discharge…MSRP: $36.29Decrease Quantity of BW1229 – 12 Volts 2.9Ah -Terminal F1 – AGM Battery – HX12-2.9 – BW1229TIncrease Quantity of BW1229 – 12 Volts 2.9Ah -Terminal F1 – AGM Battery – HX12-2.9 – BW1229TPrice:
Recommended Reading: How Long Do Lithium Ion Batteries Last
What Voltage Should A Car Battery Be
Image: Car Battery Voltage Chart
The above chart gives an indication of what the voltage should be at different states of charge and operating conditions. This is intended as a guide only as the voltage reading will be effected by the battery age, technology and temperature.
Fully charged voltage
A fully charged car battery voltage should be 12.6v or above, this is with the engine off. To get a true voltage reading of the cars battery it is important to measure the voltage after the car has been sat for a period with the engine off, preferably overnight, this provides you with the car battery open circuit voltage or also know as the resting voltage. Measuring the voltage shortly after the engine has been running can give you a higher, misleading, reading.
If the voltage is below 12.6v it indicates that the battery isnt fully charged or has a fault. The voltage doesnt have to differ much from 12.6v for it to indicate a discharged battery. At 12.2v the battery is in effect 50% discharged.
Voltage when the car is starting
When you start your car, the battery provides the necessary power to the starter motor to turn over the engine. During starting the batteries voltage will decrease for a short time, before going up to the running voltage .
During starting a healthy car battery voltage should be 10v or higher. As mentioned above cold weather needs to be considered as this will decrease the voltage and increase the amount of power to turn over a cold engine.
Finding The Cause Of A Key Off Current Drain
If the key-off current reading is above specifications , the current drain is too high. It’s time to start pulling fuses and relays to find the fault.
Remove fuses and relays one at a time to find circuit that is draining the battery. Or, use a voltmeter to check for a voltage drop across each fuse. A voltage drop reading would indicate current flow in the circuit.
Refer to your vehicle owner’s manual or a wiring diagram to identify the fuses and relays. Then pull the fuses and relays one at a time until the current reading drops. Avoid pulling the fuses for the PCM or other KAM-sensitive modules until you have checked all of the other circuits.
Once you’ve found the circuit that is causing the excessive current drain, check the relay, switch, module or other components in the circuit and replace as needed.
Recommended Reading: Best Battery Brands For Cars
When You Want To Make Your Car Run What’s The First Thing That Comes To Mind You Guessed It A Healthy Battery
The best way for your car to have a long life is by taking care of its battery, thats why its a crucial step to routinely check your batterys voltage.
Checking the state of charge of a car battery is vital to avoid problems in your vehicle. Because of this, regular battery maintenance should always be on your priority list especially if you use it on a daily basis. However, some people ignore it for a long time not until they notice an issue with their cars.
But even if you’re not experiencing any issues, it’s smart to take readings and make sure that everything is in order. A high or low voltage can mean serious problems with your engine and electrical system. In this article, you will learn how to properly check your car battery voltage with or without using a multimeter. By following the instructions below, it will help you determine your batterys problems ahead of time.
The Ideal Car Battery Voltage
Measuring your car batterys voltage can help you determine how charged your battery is. A perfect voltage with the engine running is between 13.7 and 14.7V. With the engine off, it should be 12.6 volts. If the battery isnt fully charged, it will diminish to 12.4V at 75%, 12V when its only operating at 25%, and down to 11.9V when its completely discharged.
Don’t Miss: Change Battery In Vw Key Fob
Diagnosing A Car Battery That Runs Down
by Larry Carley copyright AA1Car.com
You go to start your car and discover the engine won’t crank because the battery is dead. Now what? You get somebody to give you a jump start, or you connect the battery to a charger and charge it up until it has enough juice to start your engine.
The next morning you go to start your car again, and the same thing happens. The battery has run down and the engine won’t crank. What is wrong?
What Is The Voltage Range Of A Car Battery
As it is very important to know about the voltage of the car battery and knowing to test it by yourself also has vital importance. You must know the voltage ranges of the car battery. This is because if you know the voltage ranges of the car battery, you will be able to tell the health of your car battery and you will also be able to tell when it is time to change your car battery.
Voltage range of the car battery when the battery is fully charged.
If your car battery is 100% health and it is fully charged, then the voltage reading it must provide will be 12.6 volts. This is the voltage reading that tests you that not only your battery is fully charged, but it also has the health to store charges around 100% of its rated capacity.
Read Also: Nissan Leaf Battery Replacement Cost
What Is The Ideal Car Battery Voltage
While most people understand that car batteries are 12-volt DC batteries, theres a lot more to consider than just that. Car batteries actually have a voltage range, which affects its performance and lifespan. A car battery voltage range test is often the key to finding out all the necessary details about your batterys overall condition.