I acquired these Panasonic 3.7V 3400mAh batteries NRC18650 to replace AW IMR 18650 3.7V (7.4WH) 2000mAh who were already very good, but without protection. These new batteries take longer to discharge me vapoter more than one day quietly. They allow me to double security: internal battery protection circuit coupled to the cutting my electronic cigarette Innokin iTaste VTR. I recommend this course.