[Vwdiesel] OT, boat battery wiring question

[Dave Cook]

Hey all, looking for advice on how to best hook up two batteries in my old boat.

Basically what I would like to happen is have the radio only draw off of one battery but somehow have both batteries involved when starting the engine, and have both batteries be charged when the engine runs.  So both batteries are connected to the engine when starting/running but only one of the two is powering the radio.  Any way to do that?  

If not:
if the two are just hooked up in parallel, and the radio was on for a bit with engine off, would it draw off both equally?  And can I consider the CCA rating of each combined?

Thanks for your collective wisdom.


Dave Cook