Q:

Should I overcharge mobile phone before first using?

When I first buy a mobile phone or phone battery I used to know i should charge it about 8-10 hrs switched off the phone. 
But i don't know if its actually necessary to overcharge a battery for its longevity. 
So should i overcharge my new mobile phone or just charge it until it get fully charged. FYI: my battery is Lithium Ion Battery.

A:

When the battery is first put on charge, the voltage shoots up quickly. This behavior can be compared to lifting a heavy weight with an elastic band. The lifting arm moves up quickly but the weight lags behind. The voltage of the charging battery will only catch up when the battery is almost fully charged.
Li-ion cannot absorb overcharge, and when fully charged the charge current must be cut off. A continuous trickle charge would cause plating of metallic lithium, and this could compromise safety. 
Source Battery University

