Going to a dual battery ACR
ACR stands for Automatic Charging Relay. I wanted to upgrade from one battery to two. The ACR automatically combines battery banks when charging and isolates the batteries when discharging. The start isolation option protects electronics on board from voltage sags and spikes during engine cranking.
The ACR has two load connectors on its back panel. "A" connector goes to the positive terminal of the Starting battery and "B" connector goes to the positive terminal of the House battery. Both batteries' negative terminals get connected to a common bus bar. A 2 amp fuse is between the House Battery and the ACR and between the ACR and the Start Key Switch.