The intended role and benefits of ACRs are clear but some aspects of an ACR are not so simple. You have to understand that we deviate a little from the Blue Sea instructions because intially they envisioned a single bank charger to maintain both banks and even stated this fact. The largest anticipated draw at rest was instrumentation like a depthfinder. Blue Sea did not envision this product being used for massive stereos with massive battery banks that are deeply depleted and therefore must be charged/conditioned independently. You will NEVER see an ACR used between a starting battery and a large trolling motor bank because that will exceed the functionality of an ACR. Yet we have placed this device in an application with a similar demand and where its behaviors will change under different circumstances. So in our application an ACR may increase our dependency on AC shore charging and we definitely need isolated shore charging. The 5511e dual circuit switch becomes an essential appendage, not only for isolated shore charging but in some applications it is necessary to manually circumvent the ACR.
We have analyzed every possible scenario in arriving at our recommended wiring scheme. MLA and many others, like Earmark, have independently arrived at the same conclusions.

Earmark Marine