Content

• To step
• Method 1 of 4: Test an alkaline battery
• Method 2 of 4: Using a voltmeter to test lithium and alkaline batteries
• Method 3 of 4: Checking a car battery
• Method 4 of 4: Check a phone battery
• Warnings

There are many different types of batteries, and you can test all of them to see if they are charged or not. Alkaline batteries bounce as they diminish, so you can drop one on a hard surface to see if the battery bounces or not. Measure the voltage (and thus the charge) exactly with a multimeter, voltmeter or battery tester. You can also test the battery of your car with a multimeter or voltmeter. Finally, you can test your cell phone battery using an app that allows you to run a diagnostic scan, or have a cell phone retailer inspect the battery.

To step

Method 1 of 4: Test an alkaline battery

1. Hold the battery upright for about 5-8 cm over a hard, flat surface. As alkaline batteries diminish, zinc oxide builds up inside, making the battery bounce more easily. This simple drop test will help you determine if a battery is getting old. Hold the battery over a hard, flat surface such as a table or marble counter. Hold the battery upright so that the flat end is facing down.
   • For AA, AAA, C, and D batteries, hold the battery so that the positive side is facing up.
   • Hold a 9 V battery so that both terminals point up and the flat end down.
   • A wood surface is not the best choice for this test. Wood absorbs more energy and objects bounce less well.
2. Replace the battery if it bounces when you drop it. Watch how the battery behaves when it hits the surface. A new battery will pop down without bouncing. It can roll on its side, but will not bounce back. An older battery will bounce several times before falling over. Use the battery behavior to see if it is a new or old battery.
   • Remember, if the battery bounces, it doesn't mean it's broken. It just means he's older and starting to lose his charge.
   • This is a useful test if your batteries are all mixed up and you can't tell which batteries are fuller.
3. Compare the bounce to that of a battery that you know is dead when you need help. An empty battery can give you a better frame of reference for the battery you are testing. Get a battery that doesn't work when you put it in a device. Then drop the two batteries next to each other and compare the bounce behavior of both.
   • When the battery is empty, it will bounce higher than a new one. Compare the bounce of the two batteries to determine the specific condition of the battery you are testing.

Method 2 of 4: Using a voltmeter to test lithium and alkaline batteries

1. Find the positive and negative terminals on your battery. For an exact measurement of the charge of a battery, you use a voltmeter. First, find the positive and negative terminals on the battery you are measuring. These are indicated on the battery.
   • This method works for alkaline and rechargeable lithium batteries.
   • On AA, AAA, C, and D batteries, the negative side is the flat side and the positive side has a protrusion. With a 9 V battery, the smaller rounded terminal is positive and the larger hexagonal terminal is negative.
   • Lithium batteries come in many forms, so look for the markings on the battery to determine the positive and negative terminals.
   • You can also use a multimeter for this test, but make sure you measure in volts instead of amps or ohms.
2. Set the level of the voltmeter to the DC setting. Voltmeters and multimeters measure AC and DC current. All batteries use direct current (DC; direct current). Turn the knob on the front of your voltmeter to DC before you measure anything.
   • Some voltmeters require you to choose a maximum level for the current you are testing. With most, the lowest setting is 20 volts. This is enough for all common batteries, so set the meter to 20 volts if you have to select a level.
3. Touch the positive and negative pins of the meter to the positive and negative terminals of the battery. On a voltmeter, the red wire is the positive. Hold the pin of the positive wire against the positive terminal and the negative against the negative terminal of the battery.
   • If you mix up the wires, it will not damage the battery. But the reading will be negative rather than positive.
   • Regular household batteries will not shock you during this test, so don't worry about that.
4. Hold the pins against the battery to get the volt reading. The meter will produce a reading within seconds. Use this to determine whether the battery is sufficiently charged or not.
   • Fully charged AA, AAA, C and D batteries have a 1.5 volt charge. A 9 V battery has a charge of 9 volts. If the charge is more than 1 volt less than where it should be, replace the battery.
   • A normal charge for lithium ion batteries is 3.7 volts, but this can vary. Check with the manufacturer to make sure the battery is fully charged.
   • A 3.7 volt lithium battery will usually stop operating at 3.4 volts, so charge or replace the battery when approaching this level.
5. Load test with alkaline batteries for the most accurate result. A load test measures the capacity of the battery when it is in use. The better multimeters have two load settings, 1.5 V and 9 V. For an AA, AAA, C or D battery, set the voltage regulator to 1.5 V. Set the voltage to 9 V for a 9 volt battery. Touch the black pen to the negative end of the battery and the red pen to the positive end to test the number of milliamps in the battery.
   • A new 1.5 V battery will indicate four milliamps and a new 9 V will indicate 25. The readings as below indicate that the battery is empty. At 1.2-1.3 V, this is usually when most 1.5 V batteries become weak.
   • This particular test will not work on a lithium ion battery as multimeters have no load settings for such voltages.
6. Place the battery in a battery tester for easy measurement. These devices are easier to use than a multimeter, although they cannot indicate as much as a multimeter. These testers have a slider that moves back and forth to adjust to the different sizes of the battery. Open the slide and insert an AA, AAA, C, or D battery into the slot, with the positive side touching the slide. Then check the display to read the voltage.
   • To test a 9 V battery, some meters have a separate port to hold the battery against for a measurement. Check your meter to see if it has such a function.
   • Some meters can also test lithium ion batteries if they are in the shape of standard alkaline batteries, but not if they are of a non-standard shape.

Method 3 of 4: Checking a car battery

1. Pay attention to indications that the battery is empty when you start the car. You usually don't need a test device to see that your battery is empty. If you turn the key or press the start button, your engine will do nothing at all. Headlights will not turn on either, and if they do, burn very dimly.
   • If your battery is low, the car can make an attempt, but will not start properly. While that's not always a battery problem, it usually is.
2. Turn off the car and open the hood to access the battery. Turning off the car before testing the battery is safer and will make it a little easier. If you are not sure where the battery is, consult the car owner's manual. Lift the hood and look for a black rectangular box with positive (red) and negative (black) terminals.
   • The battery may be covered with a plastic cover. If so, consult the manual. You will probably have to loosen a few screws to remove the cover.
3. Use a multimeter or voltmeter to check your battery. If the device is digital, turn one of the devices to DC voltage. Place the end of the black probe on the negative pole and the end of the red probe on the positive pole. Note the reading on the multimeter. The display should now show the number of volts.
   • If the battery is at or above 12.45 volts, then your battery is still in good condition and any problems you have are likely caused by something else.
   • If your battery shows a lower charge, it won't start your car consistently, and your battery may need to be replaced.
   • A car battery tester will do the same. All you have to do is place the black clamp on the negative pole and the red clamp on the positive pole.
4. If you don't have a multimeter, have your battery checked at a garage. Most auto parts stores and auto repair shops will want to test your battery to see if it is dead. However, they will often want to sell you a new battery!
   • Most workshops will even fit you a new battery if you don't know how to do this.
   • If your battery is empty, you may be able to get it to work or charge it with a "jump-start", so that you can at least get to the garage.

Method 4 of 4: Check a phone battery

1. Check the battery of an iPhone with the Apple Support App. Download this app if you don't have it on your phone yet. Start a chat with one of the technicians, who will walk you through diagnosing your battery. The diagnostic report will be sent to the technician, who will be able to tell you how healthy your battery is.
   • Usually you have to go to Settings, then to Privacy, and finally to Analytics. Make sure "Share iPhone Analytics" is checked. If not, press it to allow the technician to view your analysis reports.
2. Use a third-party app to test an Android battery. Download an app designed to test the health of your battery, such as AccuBattery. Open the app and follow the onscreen instructions to set it up. Then use your phone as you normally would for at least a day. After a day, open the app to view information about your battery health. You get more accurate information after weeks or even months of using the app.
   • You can also use third-party programs such as Coconut Battery to test an iPhone, but you must connect it to a Mac to do this.
3. Visit a cell phone retailer to have the battery tested or replaced. Mobile phone shops can perform a comprehensive test on your phone's battery and check its performance. For the iPhone, an Apple Store is the best option because it has everything you need to have the battery checked. Visit a store that sells smartphones and batteries to have your Android battery analyzed.
   • These stores can also replace your battery if it no longer works properly. They may need to order the part if it is out of stock.

Warnings

• Avoid tampering with batteries. Although unlikely, you can short circuit the battery. You know when that happens because the battery heats up. If so, immediately take the battery outside and place it on a non-combustible surface, such as a concrete driveway. Don't touch it again until it cools down.