The ACR will trigger and connect (parallel) the batteries when the charge voltage of either of the battery
banks rises above 13.0v. I.e. the ACR doesn't care what the charge source is, it just cares what the voltage is -- it's basically a voltage controlled relay. MainSail's site has some info on ACRs.
I'm a big fan of "main" and "aux" banks for boats like the C30. I've got a pair of CG6's under the chart table as "main" - do absolutely everything with em. Start the engine
, etc... They're bank A on my switch.
I've got a G24 under the starboard settee that's the "aux" battery. It's B on the switch and it's maintained with a little trickle charger
. (I'm plugged in most of the time)
The solar feeds a breaker on my panel and thus would charge whatever battery was switched to.
I never use the "B" bank. It's only purpose is to start the engine
if I kill the main bank. So I get a much more available daily AH discharge capability (~120AH) than I could from a single
battery. But I'm still able to start up if I kill the main.