Here's what happens:
* Massive current flow: A very large current will flow from the positive terminal, through the ground wire, to ground, and back to the battery via the chassis or other ground points. This current is far higher than the battery is designed to handle.
* Overheating and melting: The ground wire, the positive terminal connection, and possibly other parts of the circuit (like the battery cable) will overheat rapidly. The wire could melt, possibly causing a fire. The battery's internal components could be damaged.
* Battery damage: The sudden surge of current can severely damage the battery, potentially rendering it unusable. It could even explode or vent corrosive gases.
* Potential for injury: The high current and resulting heat pose a significant risk of burns and fire.
In short: This is extremely dangerous and should never be done. Always ensure that the positive and negative terminals are connected correctly.
