12v accessory outlet
I have a battery tender connector already on the bike, with a 3A fuse I believe.
I bought a cigarette lighter extension cord from radio shack. Cut the wire in two and discarded the male end of the extension. Then had an extra "battery tender" style plug lying around - and just spliced that into the female cigarette lighter portion of the cord (twisted wires together, soldered, wrapped in electrical tape).
WARNING - those battery tender connectors will have different polarity depending on what type of cable you have lying around. One meant to be a pigtail on the bike will be wired differently from one meant for an accessory. So you should check the polarity with a voltmeter before you splice it in. I found the one I used reversed the black & red wires because it was meant as a pigtail, not an accessory plug.
Anyway, I have bags on my bike, and I can easily slip the wire into the bags to charge while riding.
Another word of warning - make sure you don't overload the fuse rating. Battery tenders have small fuses. If you need lots of power (for an air compressor lets say, in case of a flat tire) - you should wire a separate pigtail to the bike with a larger fuse. I happen to also have a heated clothing connector with a large fuse. I bought a small "conversion" wire from the clothing style connector to a standard battery-tender styled connector -so I can use that for higher powered devices.




