The Sony Ericsson S312 is a budget, lifestyle dual-band GSM mobile phone, with a focus on K. K200; K210; K220; K300i; K310i; K320i; K330i; K500i; K510i; K530i; K550i · K600/K608 · K610i; K630; K660; K700i · K750i · K770i; K790/ K800i. Sony Ericsson phones are becoming more and more popular and you usually see people 1.7k. Rate this App. Sony Ericsson Update Service screenshot. The Sony Ericsson K850i was a high-end mobile phone when released in October 2007. It was announced in June 2007 as the flagship product in Sony Ericsson's K BST-38 3.6 V, 930 mAh, lithium polymer; Talk time GSM/UMTS: Up to 9 h/3 h 30 min; Standby Firmware list edit S302; S312 · S500; S600; S700i.