I don't think so. These are lithium ion battery. They do not have the memory effect of the old nickel cadmium's. You can charge it from half, put it over night, no problem at all.. it will continue to work until it runs out of capacity to hold juice all of a sudden. That's how lithium ion batteries works.
When you first get your iPhone 5, make sure you charge the battery to 100%; the duration doesn't matter. If you are using your computer, make sure the computer is ON; if it is OFF or in sleep mode, the battery will drain. Consult your user manual for details.
no no no no no... thats actually REALLY GOOD TO. IF YOU CHARGE IT OVER NIGHT BEFORE YOU USE IT IT GIVES YOU A LONG AND STRONG BATTERY LIFE! IF YOU USE IT BEFORE CHRAGING OVER NIGHT IT KILLS YOUR BATTERY LIFE!!! TRUST ME BRO!