I tried Magic Lantern on my 50D. Works otherwise but when using it, the camera battery seemingly runs out a in just a few minutes. That's what the indicator shows and then the camera shuts down.
Of course, the battery doesn't really empty this fast and I can just restart the camera. But then the same happens again. Quite hard to shoot movies in less than two minutes :D
In normal use (without Magic Lantern) the battery works fine.