What are the consequences of a battery short circuit?

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What are the consequences of a battery short circuit? [Copy link]

Battery short circuit means that the positive and negative poles of the battery are directly connected by wires to form a circuit. First of all, it depends on what kind of battery it is, or how much "energy" the battery has.

1. If it is an ordinary dry battery, generally no violent phenomenon will occur. Because ordinary batteries have large internal resistance and small energy, they cannot "burn" vigorously. For example: after an ordinary No. 5 battery is short-circuited, there will be no change in appearance. After a while, if you touch the battery with your hand, you will feel that the battery becomes warm and hot.

2. Alkaline batteries and high-capacity batteries. At the moment of short circuit, you can see obvious sparks in the dark. The current is much larger than that of ordinary batteries. At this time, the power cord will become hot, and the battery will also heat up quickly, and it will soon be hot to the touch. It may cause an explosion after a while.

3. Rechargeable batteries. The internal resistance of this type of battery is quite small. Once a short circuit occurs, the consequences are serious. For example, when two fully charged No. 5 rechargeable batteries are installed in the battery box and the positive and negative poles of the power supply are accidentally short-circuited, the current will immediately burn the power cord until it smokes and turns red. Within a few seconds, the glue around the wire (with a certain resistance) will melt. Even if the wire is not fused, the battery will heat up, burn or even explode.
(When a thicker power cord is selected, the wire will not burn, but the possibility of battery explosion is higher.)

The above are some visible phenomena. As long as you are willing to burn the battery, battery box and wire, you can do multiple experiments. (Because the thickness of the short-circuit wire is different, the battery is different, and the length of the short-circuit line is different, the experimental results will be slightly different. However, doing these experiments is equivalent to breaking glass to listen to the sound, which is not very meaningful, wastes money and is very dangerous. This site does not recommend you to do such experiments. The above is just some summary of the site owner's experience over the past decade.)

In addition to providing electrical energy (maintaining electromotive force, that is, voltage), the battery is also equivalent to a resistor in series, which is the internal resistance of the power supply. The short-circuit wire also has resistance.
The ideal power supply should have no internal resistance, but the internal resistance of the power supply always exists, even if it is very small. You can also think of it this way. An ideal power supply is supplying power to two series resistors-the load resistance and the internal resistance of the power supply.

Why might an explosion occur?
This site believes that relatively large amounts of energy are concentrated in a relatively small volume and require to be released in a relatively short period of time, and explosion is their only way of expression.

zcgzanne

This kind of post can be supported, but it is not recommended to do the experimental class, haha