Battery Explosions - Causes and Prevention

Battery explosions are serious accidents which can cause severe injuries and burns to operating personnel and damage to equipment.  Explosions in batteries are caused by accumulation of gas inside the battery.  The gas is formed when the electrolyte(usually acid) gets electrolysed resulting in the formation of gas, usually hydrogen.  Hydrogen is extremely combustible.

This acculumulated gas sometimes shows up in the form of a bulge in the batteries.  These batteries should be replaced immediately.  These explosions may be triggered by a short circuit inside the battery or a sudden load which results in high current, such as jumpstarting a car.

You can prevent battery explosions by making sure that the batteries are charged only by the correct chargers provided with them.

Ensure that the battery connections are properly tightened.  This can prevent sparks due to loose contact.  

Avoid sparks or naked flames near the battery bank.

Ensure that no overcharging takes place.

Do not short circuit batteries.  Cellphone batteries should not be carried in your shirt or trouser pockets where small coins can short them.

Do not dispose off batteries in fire.

Batteries can also explode if they are suddenly subject to mechanical impact or deforming forces.