QUOTE(flipb @ Sep 23 2011, 02:36 PM)
(Other than forgetting to re-tighten it after I've left the car parked for a while.)
Oh yeah, I did that plenty of times. It falls under the same heading as leaving your steering wheel in the house. But the corrosion wasn't something I could see unless I took the thing apart. It simply got increasingly tough to screw it down hard enough to make good contact.
Sidenote: You can get a battery cutoff from Pegasus, Summit, or any of the other normal racing outlets. But the pricing is nearly always better at Racer Parts Wholesale.