[stavely]

I'm just fitting one of these to my bike. I thought it would run off the usb under the seat, but to my surprise there is a power unit in the box which needs linking in to the bikes general wiring.
Do i need this, or will it run and charge just fine off the mobile phone USB socket already on the bike?

 

[LadyBishop]

Dont know about the Garmin but when I've powered my iphone from the USB it is fairly weak and slow. Its actually run out while being used as satnav while being plugged in....

 

[TC3]

I had a spare power lead for the zumo 390 bike mount. Cut off the box and just added a usb plug. Sits in the underseat usb power and works fine

 

[Deano968]

I connected mine directly to the battery, running the wires under the tank (I didn't remove the tank, just lifted it and cable-tied the Garmin wiring along the inside of the frame). You have to be aware that it draws from the battery even if the bike is switched off this way. I only use mine on the road traveling along so this doesn't worry me - generally I take it off when I get to my destination which you'd probably do for security reasons anyhow.