Re: Switching batteries to start the motor.
It all depends on how it's wired. In most cases, the charging source goes to the C post of the switch, which determines two things: when charging is present, which battery gets charged, and when being used, which battery supplies the power. Don't combine two banks unless charging is present.
Want to learn more? Read the post above or below this one.
Reply #4, here: http://forums.catalina.sailboatowner...ighlight=honda
Stu Jackson, C34, 1986, M25 engine, Rocna 10 (22#)