I installed two yesterday..
One for gps and other for phone charger... (got an iphone with very crap battery..)
They are both attached to the handbar Can make pictures id U want

 

I basically just used a battery tender type. I hooked it direct to the battery and used velcro to put it dead center above the tach and speedo under the double bubble. Good spot for anything in a tank bag.

 

Here is a clip I found on you tube that I really really like hehe. This clip covers installing a cigarette lighter power adapter etc in a way that any ding bat half witted person could do hehehe. I also like how it doesn't involve any cutting etc of anything. I'm def. going to be doing this next day off which also means next full day of riding i'll have hehe.

 

Uukey, I just left 50 cm of wire and cutted the rubber off from other edge and loosened a bolt(connected to body frame) on right side tied the strings over the bolt (connected to the body frame), tightened the bolt and straped cigarette lighters onto handle bar... just simplest way I could of thought