Sometimes batteries get weak or completely go out of charge. But with alkaline batteries checking their charge might be hard. Therefore, various testing methods have been developed to check whether the battery has any charge left or it is in bad health. Some of these methods include a drop test where you drop the battery to the floor observe its bouncing behavior. Other testing methods include using a voltmeter or multimeter to test these batteries, like a PP3 9V Battery. In this article, we will focus on testing alkaline batteries by using a voltmeter.
Identify Positive and Negative Terminals
A voltmeter is very effective in getting the exact voltage measures or the battery’s charge. The first thing that you need to do is identify the positive and negative terminals of the battery. Identifying them is not hard as they are already marked on the battery.
- This method is appropriate for Alkaline and rechargeable lithium batteries.
- On AA, AAA, C, and D batteries, the flat side is negative, and the positive side has a little protrusion. On the 9V battery Tesco, the positive side is the rounded terminal, whereas the negative side is the hexagonal terminal.
- Lithium batteries are marked as positive and negative sides, so they are easy to identify.
- You can use a multimeter as an alternative for this test, and you have to set it at volts rather than amps.
Voltmeter Level to DC Setting
Voltmeters and multimeters are designed to measure both alternating and direct currents. Before starting and taking a reading, turn the knob of the voltmeter and set it up at DC to take accurate readings. In some voltmeters, you will have to select a maximum level for the current that you will be testing. On the majority of the voltmeters, the minimum setting is 20 Volts. This level is appropriate for almost all batteries, so if the voltmeter requires you to pick a certain level, set it up at 20 Volts.
Touch the leads to the Terminals
The third step involves touching or attaching the leads to the terminals. Voltmeters have two leads, one positive and the other negative lead, identified through their colors. The red lead is positive. Therefore, you have to touch the positive lead with the positive battery terminal. On the other hand, the black lead is negative; therefore, touch the negative lead with the negative battery terminal.
If you mess up this step and mix match the leads and terminals, this will not cause any damage to the battery like a PP3 9V battery, but it will give you the readings in negative values rather than positive ones. You do not have to worry about getting an electric shock as common household batteries do not have such capacity.
Get the Volt Reading
In the 4th step, you need to hold the lead to the battery to get accurate volt reading. It will take only a few seconds to get the reading from the voltmeter. From that reading, you will be able to determine battery health.
- If the AA, AAA, C, and D batteries are fully charged, the voltmeter will show a reading of 1.5 Volts. A 9V PP3 battery Tesco will have a reading of 9 Volts. Replace the battery if the charge is 1 Volt less than the required charge.
- For example, the normal charge for lithium batteries is 3.7 Volts, but this charge can differentiate based on the use and nature of the battery. For that, you will have to check the manufacturer’s requirements.
- The lithium-ion battery with a charge requirement of 3.7 volts stops working at 3.4 volts, so if ever it reaches that level, you need to change your battery.
A load test is performed to get the most accurate results. This testing method involves checking the battery while it is being used. The high-end multimeters have two load points which are 1.5V and 9V. The load setting of 1.5 volts is appropriate for AA, AAA, C, and D batteries. For this, you need to hold the black probe, which is the negative one, to the negative end of the battery. Similarly, hold the red positive probe to the positive end of the battery to accurately find out the milliamps.
The way to tell that a battery is fresh is by the readings. If a 1.5V battery gives a reading of 4 milliamps, it means it is a fresh battery. Similarly, if a 9V battery like a PP3 9V Battery Asda shows a reading of 25 milliamps, it is a fresh one. The 1.5V batteries will start to get weak when it shows a reading of 1.2-1.3Volts. This load test does not work for lithium-ion batteries since the voltmeter does not have load test settings for their voltages.
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