Replacing 12 volt batteries with 6 volt
I am replacing 3 batteries that are configured as 2 for the house bank and 1 for starting with 2, 6 volt Trojan batteries. When I bought the boat, I updated the battery switch to a Blue Seas Switch that controls the rate of charging and prevents overcharging from solar and trickle chargers. for the house bank and starting battery and gives the option of choosing 1 or 2 or combining them.
My question is: If 6 volt batteries are connected in series to provide the necessary 12v, then it seems I will no longer have a dedicated starting battery.
Is this correct?
Thanks for your help.