Go for a hybrid approach, or an old school technique.
Hybrid, mark where you were, are, go into mission and create a quick mission marking your spot. Becarefull and pay attention to AGL vs. MSL settings before using. Then RTH, change your battery, reverify your new mission settings, particular AGL vs. MSL, if ok, then start, use mission to position to where you were, stop the mission, exit mission mode, go to camera mode. If it is a location you routinely need to position to, setup a regular mission for that, use mission to position, then exit, resume what doing in regular camera mode.
Old school technique, enable GPS display on your app, note the location (write it down, screen shot, etc) as well as alt, then rth, swap battery, then simply fly back to that location.