In power supplies, polarity is an essential characteristic. In old batteries or in products subjected to mechanical stress, the designations may not be readable, therefore, determining where the “plus” and where the “minus” can be very problematic.
Content
What is battery polarity?
The polarity of the battery determines the movement of electrons from one pole terminal to another. For the operability of a large number of electrical appliances, this parameter is decisive.
To accurately establish the polarity, you will need to use special devices, but in some cases you can do without them if you have information on how to know this parameter by certain signs on the element’s body.
How to determine the polarity
In the presence of the “+” and “-” designations, the determination of the polarity will not cause any difficulties; a completely different situation may arise when such instructions are absent on the battery case.
Have a pill
For flat tablets, plus is always on the surface of a larger area. After a positive conclusion is detected, the opposite contact will be negative.
Using a digital voltmeter, you can set the correct polarity, if the red probe is connected to the minus of the battery, and negative to the plus, then a minus appears in front of the number that indicates the voltage. This indicates a wrong connection, that is, the red probe should always be connected to the plus of the battery.
Using an arrow voltmeter to determine the correct connection is even easier. If the connection is incorrect, the arrow of the device will deviate to the left, which is unacceptable for such a measuring device.
Note! If you mix the probes when determining the polarity, then nothing wrong with the battery or device will not happen.
Cylindrical
For round batteries, the plus has a slightly convex plane, so it will be extremely difficult to mix up the positive and negative conclusions, even if there are no designations on the product case.
If there are flat contacts on both sides, this parameter can be checked using measuring instruments, and almost any dial indicator can be used for this purpose.
Such elements have an electronic coil, which when voltage is applied deflects the arrow in a certain direction. For the accuracy of the experiment, first connect the battery with the known location of the contacts to the arrow, and then diagnose the test sample.
Kroons
The crown has a positive output of a convex shape and less than a negative one; moreover, such a battery element is connected by means of a special terminal block, in which the contacts also have different diameters. You can also check the polarity using any current measuring device.
Can polarity change
In order for the polarity to change in the battery, it must be half discharged, while it is installed in series between elements with a normal voltage indicator. During the operation of the device, a weak element will completely lose its charge and will be reversed over time.
When the batteries change polarity, an explosion of the cell may occur, and lithium batteries may catch fire, so only batteries equal in voltage should be connected in series.
What will happen if mixed up during installation
Modern electronic devices are generally well protected against polarity reversal.If the batteries are installed improperly, protection will be triggered to prevent the passage of electric current.
If there is no protection, then many electrical appliances can be disabled in this way. For some devices, the polarity value does not matter, for example, in flashlights with incandescent lamps.
Have questions or have something to add? Then write to us about it in the comments, this will make the material more complete and accurate.
