I have had a Nitecore i2 charger for over a year. and day before yesterday one of my batteries would not charge all the way. The other one would the, they are Sony VTC fours and I went and bought two new ones today. But now I'm still having the same problem one of the new ones is not charging. I have swapped slots with the batteries but both of the slots is saying that one of the batteries is fully charged while the other slot is halfway charged. both slots are working but it is saying that one of the batteries is halfway charged for some reason. does anyone have any idea what this could be. keep in mind that this is with the two brand new batteries I bough today also.