I recently replaced my 2 batteries and trays in my 270FV with a Group 27 battery for starting and Group 31 Deep Cycle battery for house replacing the 2 Group 24 auto batteries that came with the boat when purchased last year. In order to determine which switch position was Start and which was Deep Cycle, I installed one battery first and left the other out. Turned off shore power and battery switch to position 1 - engine starts. Moved switch to position 2 - engine starts again. WTF? Am I missing something? Batteries don't look like they are wired in parallel but would have to pull the switch to verify.