The release of the Fujifilm NP-W126S battery caused a lot of confusion because it was similar to the NP-W126 battery it replaced, but necessary for newer cameras to function properly. Now there are quite a few 3rd party options available, but Europe seems to have a lot more options than the US market at this time. ultralightphotography did a thorough review of some of the batteries available today and unsurprisingly the NP-W126S battery came out as the top performer for modern Fujifilm Cameras.
NP-W126S: Amazon / B&H Photo
ecoEfficiency: Amazon
Wasabi: Amazon
Watson: B&H Photo
OAproda: Amazon
Kastar: Amazon
JCC: Amazon
FlyHi: Amazon
DSTE: Amazon
Top-Max: Amazon
BTBAI: Amazon
Pawa: B&H Photo
Duracel: duracelldirect