Many have noted that Fuji S5’s NP-150 battery is externally the same as the Nikon EN-EL3e. This of course makes sense since the Fuji S5 is a customized Nikon D200 body. However, the two batteries are not compatible as they output different voltages and have a different chip on board. If you try to place the Fuji in the Nikon camera or vice-versa, the cameras won’t work.
The chargers on the other hand look identical, and have the exact same output specifications, so some have said the two are compatible. That is, you can use a Nikon MH-18a charger with the Fuji NP-150 battery and/or the Fuji BC-150 charger with the Nikon EN-EL3e battery. If you insert the other manufacturer’s battery in the opposing unit, they do in fact appear to charge.
So, the question is, is this a good idea?
After a conversation with Steve, a very friendly and helpful rep at at Fuji Pro Repair who verified this for me, the answer is no, you should not interchangeably use the two chargers. Apparently because of the difference in chipping of the two, you will damage either the battery or the charger.
Some claim to have successfully interchanged the two chargers, however this is discouraged by Fuji and they specifically say could damage your equipment
“puddleduck” (aka Andy) at DPReview indicates that he has never actually used the Fuji charger in all the years he’s had the S5. In fact he’s never opened the package and only used a Nikon charger and it has always functioned correctly. Anecdotally speaking, it sounds like the people at Fuji are just being cautious.
I guess each will have to make their own decision here.