I bought these
B&D Battery Locks for my batteries. You can see how they work
. I like them. I have my propane bottles secured using a cable and lock.
As has been said before, this only keeps the persons looking for an easy theft opportunity away. Looking for a way to secure my portable generator, I found this comment from a truck driver who camps-
"No matter what you lock something up with, someone has a way to defeat your precautions ... common handheld battery-operated cutting wheels will fit in a coat-pocket, and go thru a chain, cable, or lock, in mere seconds, just like it was butter ... I found the best quality padlocks just guaranteed my truck-trailer doors would suffer hundreds of dollars' worth of damage, while the bad guys struggled with the lock ... the 'old-timers' taught me a better plan - 'put a cheap padlock on the doors, and then you only have to replace a padlock, not the entire door' ... so, I padlock a decent-sized cable thru my generator to my trailer frame, and then, I don't worry about it ... if they take it, they take it, that's what I pay insurance premiums for."
Right now I'm reviewing my policy coverage.
Rick