I was using Magic Lantern on my 5D M3 for well over three years, never had a single problem using it and the camera is in almost mint condition. I had to sell my 5D recently so I've uninstalled the magic lantern from in-camera using low-level format as mentioned in the FAQ and let it get back to the old Canon firmware without ML this time, removed my SD & formatted it on a laptop and now using that SD in a different camera. Now the person who bought is reporting that the battery drains completely keeping a fully charged battery inside the camera overnight. Please help out! Thanks!