Bell & Howell WV30HD Camcorder Battery Lithium-Ion(1300 mAh) - Replacement for Casio NP-40 Battery Replacement battery for the Casio NP40, Lithium-Ion (Li-ion) 3.7V (1300mAh) This Synergy Digital battery is fully compatible with the original Casio NP40 Battery. 100% compatible with your OEM battery - 3 year warranty. Made with high quality Japanese cells. Synergy Digital is a Registered Trademark