LG Viper 4G LTE LS840 official Pictures. LG Viper 4G LTE LS840 is a Smartphone of lg. The LG Viper 4G LTE LS840 Android Smartphone. Announced Jan 2012. Features 4.0″ Display, 5 MP Primary Camera, 1700 MAh Battery, 4 GB Storage, 1000 MB RAM. LG Viper 4G LTE LS840 price starts.