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Do you know how to test a battery with a multimeter? We got you.
This article explores how you can quickly test 9-volt, 12-volt, and AA batteries with a regular multimeter.
There’s not much to it, but it helps to know a few tricks to test your batteries.
So, before getting started, we’ll go over some things you need to know to test a battery. If you feel confident about your skills, then feel free to skip all this extra information.
Can I Use a Regular Multimeter to Test a 9Volt & AA Battery?
Scrolling through the vast amount of misinformation on the internet sucks. It just makes it unnecessarily difficult for those who are trying to learn a new subject.
That being said, no, you cannot use a multimeter to test your battery, so long as you have a resistor and multimeter. Sure, you might be able to put your meter on volts DC, attach the multimeter leads to the battery and get the voltage on the screen.
But that doesn’t tell us much. We just know the voltage and not the internal resistance, which we need to know to find out whether the battery is working or not.
5 Problems You’re Likely to Experience with a 12-Volt Battery
Before testing your battery, consider the following symptoms:
Dim Lights
If your battery is soon to die, it won’t be able to power your car’s electrical components. Thus, your headlights won’t light up the road ahead of you.
Car Takes Forever to Start Up
Noticed just how long it takes for the engine to start? Well, there’s a high chance that your battery is about to die.
Car Won’t Start
If the battery is the problem, then you won’t be able to start up the engine. It might crank, but it won’t start. So, take a multimeter and troubleshoot the battery.
Corrosion
As your battery gets older, the terminals of your battery can get corroded. If you take a look at the battery, perhaps you might notice all the crusty and weird substance around them. Unfortunately, this can affect your battery’s performance, leading to many performance problems.
Noticeable Smell
If your battery got damaged, you might notice an awful smell coming from the vehicle. This usually happens when the battery starts leaking. This problem is not as expected, but it is worth pointing out before testing the battery.
How to Test a 9-volt & AA Batteries Using a Multimeter
Now that we’re on the same page, here’s how to test AA battery with multimeter:
What You Will Need
Get these tools before getting started:
- Alligator clips — to properly test batteries get alligator clips.
- Resistor — without using a resistor, you cannot test a battery.
1. Insert the Leads
To start, grab the black multimeter lead and kindly insert it where it says “COM.” Next, grab the red lead and plug it in the other jack labeled “VΩ.”
2. Put the Multimeter on Volts DC
To properly test a battery, set your multimeter to volts DC. Do not set the meter to volts AC. Otherwise, you won’t be able to test your battery.
At this point, you might have noticed that your meter has plenty of options along with multiple ranges. To test your battery, set your unit to a higher voltage, meaning if you’re testing a 9-volt battery, set it to 12 volts.
3. Put a Load on the Battery
Grab your alligator clip and attach it to your red lead, then attach the other end of the alligator and put it on one end of the resistor.
Next, grab another alligator clip and attach it to the other end of the resistor. Now connect the remaining alligator clip to the black lead. You can now test your battery.
4. How to Test a 9V Battery with a Multimeter
Take your multimeter leads and attach them to the battery. Your multimeter will now show the voltage on the screen. If you get close to 9 volts, it means the battery is in great shape.
Keep in mind that you might not get 9 volts. It could read a little bit lower as the resistor is taking some power from the battery.
How to Test Your Car’s Battery Using a Multimeter
Don’t want to spend unnecessary money on a new battery? Well, it’s time to learn how to use a multimeter and save yourself some money.
1. Set up Your Meter
As always, set up your multimeter. Start by grabbing the red lead and inserting it into the hole labeled “COM.” Once that’s done, plug the red lead into the “VΩ” jack. Finally, set your multimeter to 20 volts
If you don’t have 20 volts on your meter, set it to a higher number. Please do not set it to anything below 12 volts, or you won’t be able to measure your car’s battery.
2. Turn On Your Lights
Before moving any further, please turn the headlights on for about two minutes. That way, you’ll get rid of any surface charge your battery could have. After that, shut off the lights.
3. How to Test a 12V Battery with a Multimeter
Touch the red lead to the red terminal on the battery, and then attach the black lead to the black terminal. Now check your multimeter.
If you’re getting around 12.8, you’re good to go. However, we still have to do a little bit of troubleshooting to verify your battery’s health.
4. Start Up The Car
Go ahead and start your car. Do not disconnect the multimeter leads from the battery. When the engine is running, make sure that the voltage does not drop below 10.4.
If it goes below 10.4 volts, it means there’s something wrong with the battery. But before you throw it away, make sure to clean off the terminals using sandpaper and WD-14.
If the connections got corroded, please gear gloves as this could hurt your hands. After that, test the battery again, and it should work.
How to Tell If Your Rechargeable Batteries Are Broken With a Multimeter
Don’t know why your batteries are acting up? Then use a regular multimeter to find the problem. That said, here’s how to test a battery with a multimeter:
1. Configure Your Multimeter
First, take your red lead, plug it into the “VΩ” jack, and then connect the black lead to the “COM” jack. Next up, put the multimeter on 20 DC volts.
To get accurate results, always set the voltage higher than what your battery says.
2. Test the Batteries
So, how to test a rechargeable battery with a multimeter?
To test your rechargeable battery, attach your multimeter leads to the battery. One of the leads should go on one side of the battery and the other on the other end.
The multimeter will display the voltage on the screen. If you are getting anything above 1.2V, you’re good to go. If the screen shows any number below 1.2V, it means the battery needs to go.
If you’d like to watch a YouTube video on this topic, here’s one that goes through everything you need to know:
Frequently Asked Questions (FAQs)
The following questions aim to clear up any doubts you might have after going through our how-to guide:
Can you test AA batteries with a multimeter?
- Yes! You can use a regular multimeter to test AA batteries. Simply turn the wheel to volts DC and touch the leads to the battery. Your multimeter will now display the voltage you’re getting.
At what voltage is a AA battery dead?
- You should get 1.5 volts when testing your AA battery with a multimeter. If the voltage goes below 1.35, it means the battery went bad, and you must replace it.
At what voltage is a 12V battery dead?
- If you hooked up your multimeter to your battery and started the engine, and you’re getting 10 volts, it means the battery is not working, and if it goes below 5 volts, it’s safe to assume the unit is no longer in great shape.
Do rechargeable batteries die if not used?
- Yes, rechargeable batteries die over time. They are just like most batteries out there. So, you have to charge and test them regularly to make sure they are still in great shape.
Conclusion
See how easy it is to learn how to test a battery with a multimeter? You just need to know certain tricks, and you will make it work.
But remember, you cannot test a 9-volt battery with a multimeter alone. You need a resistor and alligator clips.
The multimeter could display 9 volts, but that doesn’t mean anything if we don’t know the internal resistance.
As for your car’s battery, attach your multimeter leads to the battery and then check the meter. Finally, start up the engine and check the multimeter. If it doesn’t go below 10.4 volts, you’re good to go.