If you just need some USB power for smartphones or whatever. I have this installed. I only use it when I need to charge my phone... otherwise It's in my pocket. It's super easy (2 secs) to attach or take off. Right onto the battery tender. These were at Daytona, but there are places to buy...
For power I got this device from Amazon that gives USB power right off the Battery Tender. Works great and it can be used for all sorts of electrical devices. Pretty sweet.
Amazon.com: SAE 2-Pin to USB Charger Adapter: Electronics