I,m installing an electric fan and water pump in my 1971 Duster, 360 cid drag car ( mid 12 seconds). I want to install a second battery, do I install the second battery by connecting the positive to positive and negative to negative ( parallel ) and what size wire should I use to connect the batteries.
Hello Ken, you run + to + and -to -, this give you still 12 volts, but 2x the cranking amps, use typical battery wire, same size/gauge from your starter, ground, etc. 6 or 8
