As savage & ajayhawkfan said, it indeed looks like a powerlet socket. Many folks call this a "BMW plug". My guess is that socket is wired straight to your battery with hopefully a fuse in the wire. You could use that to charge your battery if you have a way to connect a charger that can plug in using a powerlet plug. You can buy adapters of all kinds.
You can also power accessories such as heated gear or a GPS using this plug. The position of the socket on your motorcycle suggests it was intended for charging the battery.
That explains the socket....as for charging Lithium batteries, I'm told there are things to be aware of. Somebody who knows more about that can post up.
http://batteryuniversity.com/index.php/ ... _batteries
My charger is supposedly "smart" enough to shut off when battery is full rather than trickle forever. I use it on all my batteries including Lithium motorcycle batteries, but following me can lead to harm to yourself and others.