While replacing batteries I noticed, in the compartment aft of the batteries and below the berth, about 15' of coiled battery cable. I easily could see one free end, cleanly cut and lying within the coils. The other end eventually was found lugged and attached by one of the large stainless keel nuts in the bilge. I believe this to be a grounding strap, but to what the free end should attach is not something I want to guess about. It is certainly long enough to make its way back over to the base of the mast, but I believe that a direct path would be far more desirable than one routed around the batteries, especially in the event of a lightning strike. Any insight as to the origin and/or nature of the cable would be appreciated.