I found an issue when I installed the latest ML firmware onto my camera. (2017.07.02, still there in the latest build!) When I hit record in live view mode after 2 minutes my battery starts draining very fast and dies, I bought a new battery even and it draining very rapidly too.
I don't know if that is a known issue or not, but hope it helped, btw ML is awesome, you know that!
Hope my words are correct and you can understand,