The only thing FREE OF CHARGE is perhaps a FLAT BATTERY
Here are some interesting pictures of the consequences of bad batteries.
An overcharging battery spurts electrolyte all over and corrodes the bodywork. The blue gadget in the center of the picture was used to cover the caps to prevent acid from spurting upwards but the acid went sideways!
Without the blue gadget, the bonnet gets it. Just look at the corroded spots on the bonnet.
A normal car battery is designed to last 200 cycles. The performance deteriorates rapidly after this stage.
