Sony HDR-PJ275 Camcorder Battery Lithium-Ion 1600mAh - Replacement for Sony NP-BX1 Battery Replacement battery for the Sony NP-BX1, Lithium-Ion (Li-ion) 3.6V (1600mAh) 100% compatible with your OEM battery - 3 year warranty. Made with high quality Japanese cells. Synergy Digital is a Registered Trademark