Sony Cyber-shot DSC-HX20V Digital Camera Battery Lithium-Ion (3.7v, 1200mAh) - Replacement for Sony NP-BG1, NP-FG1 Replacement battery for the Sony NP-BG1, Lithium-Ion (Li-ion) 3.7V (1200mAh) 100% compatible with your OEM battery - 3 year warranty. Made with high quality Japanese cells. Synergy Digital is a Registered Trademark