For example, if I connect my GPS or an FM transmitter to the cigarette lighter to power it, would my car battery drain of power or does it barely make a difference??
PS: I mean, if I use these gadgets while driving and unplug them when I turn my car off.
(I am driving about 1.5 hours per day.)
Also, I never leave anything plugged into the cigarette lighter when I’m not in the car, in fear that my car will get broken into.
If you turn whatever you have plugged in off, it shouldn’t cause a drain. It will if it is left on. How long the battery will last with something draining it depends on what is using the battery power. A GPS doesn’t take a lot of power to run. If you have a good battery in your car, it should last several hours before it pulls it down.