I bought Sony VTC 6 batteries about a year ago and only used some of them at the time. A few days ago I bought a few new ones. I took them out for their 1st charge today (both old and new have never been used or charged) I iimmediately noticed some differences - the new ones have a larger insulator and are slightly taller than the older ones Mass (g) : - New Battery 1 = 46.42 - New Battery 2 = 46.56 - Old Battery 1 = 45.94 - Old Battery 2 = 46.71 Are they all authentic ???