iPod Battery life question

On basically every cell phone on the planet, if you have it plugged in and charging, it will in some way try to alert you when it finishes charging the battery. Unfortunatly, not all cell phones will disconnect the power from the battery once it's done charging. That means that you are still providing excess power to the battery, and overcharging it. Since overcharging a battery of any kind, including the Lith-ion ones in an iPod is bad, I want to make sure the iPod disconnects the power when it finishes charging. Does anyone know for a fact if the iPod does in fact have this feature?