Editing AA battery (section)

==The insides of a ZnC battery==
The common zinc-carbon or zinc-chloride AA battery consists of a [[graphite]] or plastic rod in the center, paper, electrolytes, a [[zinc]] outer shell, and a plastic cover.  There is also a pressure valve at the bottom to prevent explosions.  However, the pressure valves generally will not prevent leakage or catastrophic failure of the shell if the battery is exposed to fire or extreme heat.

If a Zn-C or Zn-Cl battery is discharged too far then corrosion of the cathode, which is the zinc shell, can occur.  If this becomes corroded enough, a breach in the shell can allow electrolyte to leak out.  This is a common cause of damage to battery-powered appliances which are left unattended for long periods with batteries inside.  The electrolyte can also cause minor skin damage, and should be kept away from eyes, and not ingested.