So, unfortunately, it seems that Wasabi Power’s NP-FW50 battery that can be used to replace the batteries that are used in the a6000 and A7 II line of Sony cameras causes instability when used in a grip on the A7 II series cameras. This occurs frequently inside Sony’s grip for the A7 II series cameras and occurs more rarely when the battery is used alone inside the camera.
The screen will freeze as battery grip switches from battery 1 to battery 2, or randomly near the 20% power remaining mark, the off button no longer functions, and only full removal of the batteries will reset the camera.
This even doesn’t seem to prevent the current image from being recorded or seemingly damage the camera. But it is concerning nonetheless and is something people should know.
I’m going to speculate that while powering on or while switching batteries, the Wasabi Power battery cannot suddenly discharge the energy required of it. So some kind of fundamental error occurs in camera that requires the power sources removal. Speculation, but it seem to be in the ballpark.
Ultimately I’m not sure this battery is worth using in professional situations. The battery functions correctly in the a6000 series cameras with the only downside being quick battery depletion. But in the A7 II series… I don’t know if it’s worth it.
Cheap (two for $18.99 compared to $53 for the Sony battery).
Battery depletes quickly.
Unknown effects on camera.
If you’ve had a similar event please comment below!
Update – 07/27/2018
After some more testing, Wasabi Power’s battery CAN cause data loss when it becomes unstable and causes the A7 II to freeze up. It seems to occur during heavy use.