I recently set up the Ronin S with their power cord and a dummy battery for my A6400. It all works great, got rid of some weight on the rig and seemingly extended my run time on the 6400.

I've only used it on a few shorter jobs but wonder how long I can expect this combination to run on a charge. Should I considered a back-up Ronin S battery?

The A6400 runs on less than a watt of power.

Well, I called tech support. Another wasted call. C'mon DJI, your equipment is wonderful...but tech support cannot answer the question posted above?

I explained more than a few times to the tech person what I wrote above...and was told that there will be no impact on the battery grip as the camera is being powered by the dummy battery. Really?

They finally told me that the Ronin S runs on an amp or watt of power.

Can someone give me a real-world idea of what I should expect for battery life powering the Ronin S and A6400 with the battery grip?