Golf Cart: I have a gas-powered golf cart, can I use your system?

Yes, but please remember that if the engine is not running the battery will drain. The system does draw minimum power though (< 10A/h) so it is not a large load on the battery, however, you should run the engine occasionally so the alternator is charging the battery.

Golf Cart: I have a 48V electric golf cart, can I power it straight to one 12V battery?

No, on electric golf cars you need to connect the power source to a converter, this will draw power equally from your battery pack rather than draining one battery. Most golf cars already have a 12V converter fitted to run things like lights and sound systems.