cjc2 Loc: Hellertown PA

As battery technology improves, manufacturers sometimes upgrade battery models, Nikon normally does this by adding a letter after the battery designation. Sometimes they do it as an immediate change, sometimes when a newer model is introduces. Normally, they are compatible, or the physical size is changed to avoid problems. The final authority is the manufacturer itself. Nikon, and I would guess most others, have excellent tech support which is easy to reach. There is nothing new in my post, just a summary of what others have said before. As i've upgraded equipment over the years this has occasionally allowed me to have spare batteries without having to spend as much extra $$.