I’m going to do a 12 volt DC Emergency Lighting System. The Lights are LED 6watts each. The most number of Fixtures off of one wire will be Three. The longest run will be 70 Feet, and that’s over estimating. I’m concerned about a Voltage Drop. Will 18 gauge do it, it seems so, but no one talks about the DC Voltage drop? I’m going to use Three wire conductor, one for battery status, one for the LED Lamp and a Common, in Stranded wire. Double Jacketed.