Question for all posters in this thread—What do you use to lockout gensets that are under maintenance or repair?

In the past, at an 11-square-mile site with dozens of decentralized sets, out of desperation one day, [and hating to lift a battery terminal] I got a TWECO-brand 1/0-AWG welding-cable connector [male and female come as a pair] and cut it into the grounded-negative battery cable, with the exposed-male part of the pair connected to the frame.

It turns out 1/0- and 4/0-AWG connector sets are off-the-shelf items at welding-supply stores. http://store.weldingdepot.com/cgi/weldingdepot/LC40x.html

Later, to allow for a positive disconnection, I drilled a 5/16-inch hole through the barrel of the female connector to accept a standard long-shackle padlock.