M11 an older were 11.1V
M11X AND NEWER ARE 7.4v

My advice is to run through all of the settings, epa adjustments, and see if everything works first. Then bind it, if it binds, then run through the settings again and make sure that they are adjusting the servos and such.

Being that it turned on, I believe you are fine, and I believe the warning light is to inform you that the voltage is to high. I would presume that had you completely disreguarded that light and just used it, over time you would mess it up.

BOL.