"Sony Cyber-shot DSC-W810 Digital Camera Battery Lithium-Ion (3.7v, 1300mAh) - Replacement Battery for Sony NP-BN1 Battery" Replacement battery for the Sony NP-BN1, Lithium-Ion (Li-ion) 3.7V (1300mAh) 100% compatible with your OEM battery - 3 year warranty. Made with high quality Japanese cells. Synergy Digital is a Registered Trademark