You shouldn't use the ACC line to power equipment. At 7.5A, it's really only rated to handle turn-on circuits (relays, etc) and such. For new equipment, consider installing a new (fused) circuit directly from the battery. Alternatively, the cigarette lighter circuit is completely unused (assuming you don't have the optional ashtray and lighter). I believe that one is rated at 15A. That should be enough to power a few low power accessories.