Failed battery, or alternator is overcharging.
The bulging is caused by gassing. This is caused by overcharging or by a short circuit inside the battery. The acid inside the battery is turned to gas and it expands the sides of the battery.
Sulfuric acid fumes escaping from the battery.
Sulfuric acid fumes escaping from the battery causes this corrosion.
Usually a battery will leak because of overvoltage, overtemperature or a bad battery cell.
A car battery is made of three components, lead, sulfuric acid and water, over time the acid erodes the lead and the lead is the main charging part of a battery that is why vehicle batteries are called lead-acid
ACID's Some sour candies and sprays are almost as bad for your teeth as battery acid!
A battery acid is a variety of acid used as an electrolyte in a battery - usually sulphuric acid.
corrosion of copper, from battery acid vapors, most likely.
When lead/ acid batteries are charged, they can give off hydrogen gas.
They absorb the sulfuric acid fumes which causes corrosion.
Battery acid is made of sulfuric acid, a strong acid.
hydrogen gas being released from the acid in the battery. It mixes with other things in the atmosphere under the hood and produces the corrosion you see