Sony DCR-SR40 Camcorder Battery Lithium-Ion (800mAh) - Replacement for Sony NP-FP50 Battery Replacement battery for the Sony NP-FP50, Lithium-Ion (Li-ion) 7.4V (800mAh) This Synergy Digital battery is fully compatible with the original Sony NP-FP50 Battery. You can rest assured that this battery will work with your Sony Camera/Camcorders that use NP-FP50 and it can be charged with the original manufacturers charger. We use only high quality Japanese cells, so you are sure this battery will last for years to come. Synergy Digital is a very high reputable company that manufactures batteries and other electronic accessories for over 2 decades, all our products come with a 3 year manufacturer warranty.