Great question! I was getting low on battery last night while making the video and then charged them back to 100% when I was done. So I haven’t been in that scenario, but my guess is that as long as they’re in the case (even if the case is dead) they’ll stay turned off until removed from the case.
I will try to drain these down in the next day or so to test that out and will report back on what happens in that scenario.