According to Asus, the phone will offer around 19 hours of talktime on 3G and 9 hours of video, while the addition of the tablet battery pack will boost it to 57 hours of 3G and 27 hours of video. (t3.com)
It packs a 2,000 mAh battery which gives 30 hours of talktime on 3G network. (maktechblog.com)
The 2200 mAh battery on the 830 gives talktime of up to 14 hours on 3G networks. (gogi.in)