If your P3 has the latest firmware it will ignore the .bin file on the sd. It'll just create another txt file that states no firmware update was needed. It will not re-update every time you power on. You will not have to wait several minutes on another update.I'd disagree with this as the firmware either updates the batteries or it does not. It won't magically update them the 3rd or 4th power up. Also, leaving the firmware on the SD card means the P3 will attempt to update itself on every power up. So you would need to wait several minutes each power up just to have the firmware install stop.
I did upgrade my P3A . After 20-25 minutes the sound was D - DD . I turned it off and I formatted the card . When I turned back the phantom does this
That makes sense. Previous updates they did not say to update the RC because it states to do so in the 'How to update the firmware' document. The one release that didn't require the RC update, they specifically said you don't have to update the RC. Conclusion, update the RC unless the release notes say you don't have to.Tahoe Ed (DJI Support) says yes to the controller update.