Originally Posted by
Airframe
Thanks for the posts. I didn't think it would do anything to a C-172 other than the risk of starting the propeller when you least expect it. I've heard of one story of someone leaving the mags on a twin engine overnight and he killed the battery or left the mags too warm for too long and it did some sort of damage. Now I'm just trying to figure out the difference of turning on mags between lighter vs. larger aircraft.
There's no way.
Magneto's in any airframe, large, small, russian even etc.. work the same. They have no, none, nada, zip, zilch effect on the battery. Now if someone left the Master switch on, then yes, that's the battery switch. Master switch is not the Mag switch, and never have they been connected to my knowledge in the 100's of GA planes I've flown.