The boat I have has 2 Volvo D4 260 engines. There are 4 batteries. 1 is dedicated for starting the Port engine and the other 3 are for starting the Starboard engine and supplying the 12v power to the boat, therefore the starting amps will be going through the shunt. I cannot find out how many amps starting takes. What is the maximum intermittant power I can put through the shunt?