The sony np fw50 rechargeable battery pack is designed to provide high stamina battery life for the sony alpha nex 3 nex 5 nex 5n nex 7 digital cameras and sony a33 a55 rx10iiiii a7ii a7rii a7s a6000 a5000 cameras the battery uses actiforce technology for higher capacity and faster recharging time the hybrid lithium ion cells suffers no memory effect loss of performance on partial charge