I have a dead Photon Micro-Light II that takes two CR2016 batteries, 3 volts each. I replaced them with a single CR2032 battery, 3 volts, because that's all I have. I'm surprised that now the photon micro light works just fine. It still has a blinding bright light. But I'm guessing that it is not as bright as the original because I'm only using one 3 volt battery instead of 2, but don't know for sure. Maybe it will last longer, I don't know. what do you think.
note: a single CR2032 is the same physical size as two CR2016 batteries put together.