With the increase in my battery stock, the acquisition of a Brother labeler, and the realization that some of my early batteries are getting a bit old (but no idea how old), I came up with labels to put on all the batteries I have the data for (as well as their cases). I used to write on them with a sharpy, but some have worn off to the point I can't read them. I checked to be sure they would still slide easily into all my mods, which they do. My only concern would be any possible additional heat buildup during use or charging. Should I be or any other issue I've missed?