I had already fitted a 12v cigarette socket to my bike, it is wired to the battery for constant 12v power so I wired my Garmin's power supply to the back of the socket, quick and easy.
So if you don't have a 12v socket you should think about fitting one at the same time as you do the Garmin or if you have a socket it may save you some work.
Some of the 19 rides in my shed
2014 V2, Snoopy
2009 Wee, Pumbaa the pig
WR450F, The Blue Postie Bike
YZ250N smoker with rego, Stinky.
Yamaha MT09 (FZ09), The Scud missile.
Club Lead not Club Med.
He with the most toys wins.
Out of my depth in a puddle.
Live life on the edge you will see more that way.
Ridding a motorcycle keeps things in balance.
At the end of each trail and at the end of each day history is made.