One of the important aspect of any smartphone/tablet is the battery type it supports and its life expectancy.
In case of a Lenovo IdeaPhone S650, it comes installed with a Lithium-ion polymer battery Several devices these days comes with a non-removable battery.
In case of Lenovo IdeaPhone S650, battery is removable and hence can be easily removed.
Talking about the battery capacity of a Lenovo IdeaPhone S650device, it comes with a battery bearing a capacity of 2000 mAh This, if not the best, is definitely sufficient for a decent one day usage with rigourous data usage and video playback.
If you are a kind of person who just use a lot of camera features but dont abuse data consumption, then Lenovo IdeaPhone S650 should be able to give you a day and a half worth of battery energy.
Hope this should convince you to consider the Lenovo IdeaPhone S650if you are really worried about the battery backup of this device.