The NP-W126S is supposed to be thermally more efficient and thus able to better handle substantial loads. It appears there is some more electronics in the "S" for better measurement of voltage and such (Fuji X-cameras up to now have always been a bit imprecise in the battery capacity measurement department). This battery is also compatible with older cameras that use the NP-W126 battery pack, but users will not see any performance advantages in those bodies.

I also used my thermal camera, Flir One for Android ( iOS version exists too), to capture batteries after a heavy load. In case of long exposures in freezing temperatures you can expect much lower, but in case of continuous shooting it can easily be double of the specification or more.This product information is fully applicable to the Fujifilm series compatible batteries, "Fujifilm battery NP-W126S". Produced in China by our reliable domestic manufacturers and through our verification and sales channels to ensure product quality and safety. The frame rate and number of frames per burst varies with shooting conditions and type of memory card used.

Highly respected 3rd Party batteries like Watson and Patona, quote capacities that are very similar to the OEM battery’s capacity. When I recently got myself an X100V I was also looking for a fitting charger and in the end went with the Nitecore FX1.Apparently the cheapest aftermarket batteries fail pretty bad, but fortunately many brands offer pretty solid competitors to the original batteries. If the memory card has a capacity of over 32 GB, movies will be recorded in single files, regardless of size. Usualy, I Don't shoot video so until I bought a generic NP-W126S, I will use a NP-W126 when NP-W126S will be discharged…. The user needs to stop the charging process if they notice that the temperature display is approaching the 45°C charge temperature limit.