What happens when you short out a battery?

Answer 1

Big troubleWARNING: This is a dangerous and un-necessary thing to do to.

Generally, this is the basic definition of a short circuit. It's what happens when you connect the positive terminal of the battery directly to the negative terminal. All the current that the battery can produce, flows. This arrangement has no safety feature, except the depletion of the battery. While the battery is depleting, lots of unpleasant things can happen.

For flashlight batteries it ruins them, electrically. However it can also cause them to rupture, spilling toxic and/or corrosive chemicals. Still not a good idea.

For vehicle batteries, it is dangerous and should never be intentionally done for the following reasons:

Vehicle electrical systems, especially batteries, are not designed with short circuiting in mind, except for the fusing of the circuits, which is designed to protect the curcuits, not people.

It is not necessary. Look for another solution to the problem.

Shorting a 12 volt battery at the terminals allows a very large current to flow (300+ amps). This level of current can, and usually does, cause high heat. This can result in fire and loss of the electrolyte.

Heat, explosion, fire, or escaping electrolyte (acidic or basic) can damage human tissues. In accidents of this type: damage to eyes, hearing, any skin surface, hair, sinuses, lungs, teeth, gums, tongue and mouth linings are possible.

The conductor used to short the battery, usually gets very hot and, depending on the characteristics of the material used, can cause heat damage or possibly start a fire.

The larger the capacity of the battery, the greater the danger.

The short circuiting of any battery is dangerous and there is never a sensible reason to do it.