Auto batteries may explode through defect, abuse or accident.
Auto batteries are filled with dangerous substances such as sulfuric acid. Accident, abuse and manufacturing failures can all cause auto batteries to explode. Therefore, batteries should always be treated with great respect.
Basics
Most automotive batteries are composed of lead plates with a sulfuric acid electrolyte. Twelve-volt automotive batteries typically have six cells and a positive and negative terminal.
Cells
As part of the chemistry that makes batteries work, the electrolyte is diluted with water. During charging, the water molecules are separated into their component parts, hydrogen and oxygen.
Chemical Reaction
Hydrogen is explosive. Oxygen supports burning. Charging your battery too quickly causes it to emit gases that may explode. The gas-emitting process is called gassing.
Causes
A spark may be caused by a broken internal battery connection (i.e., a manufacturing defect). A spark may also be caused by excessive vibration or a large shock when, for example, you drop the battery. Sparks cause explosions.
Shorting
A battery might also explode if, when you were jump-starting it, a piece of metal shorts the battery terminal. Battery explosion may result in acid splatter and will certainly result in a loud bang and noxious smoke.
Tags: Auto batteries, automotive batteries, batteries explode, sulfuric acid