This is one of the easiest, cheapest and handiest mods you can do to your bike. Plus, it literally takes a couple of minutes. On big trips it allows you to charge your smart phone, tablet, GoPro or GPS when you otherwise wouldn’t have access to power. Who says you have to have an adventure bike to all the niceties!
Edit: You should also add an inline fuse directly to the wire that connects to your battery. You can pick these up for a few dollars from your local hardware/auto shop or grab one on ebay. You can also install a 12V switch to make sure you don’t run your battery flat.