I have used that same style of plug to connect up all sorts of things, compresser, tent light, sat nav.
But the comments here are valid they corrode easily and the pins get broken.
I find the better solution is to use the Hella/BMW/KTM DIN type plug where it clicks into place it has a waterproof cover and is a positive secure fit as opposed to cig lighter style, I have leads that then connect to the optimate, or a standard cig socket and all the accessories I use now have the Hella plugs or the ones with the removeable red ring so you can use them in both types of socket
http://www.clasohlson.com/uk/36-3904?gc ... tAodcjsA8w