I purchased a 6 gauge eye socket that crimped to the end of some 6 gauge wire. i attached that to a battery and ran a few inches to a power distribution block and ran two 10 gauge wires back to the car. i put a fuse a few inches from the power dist. block w/ 20 amp fuses in them. if you run the wire, do not install a fuse and you will be fine. i would not count on taped ends to keep from shorting, but you need a fuse on every wire in the dist. block. if you only want to run one wire, just connect that straight to the battery. they also sell aux ends for your batt. cable that lets you connect another wire into the side of it. I had luck at car audio places and NAPA auto parts. not sure what they have in the U.K. though.
hope that helps.