ProMariner Battery Isolator - 2 Alternator - 3 Battery - 70 AMP [12073] import_2022_09_19_071223 the V-200L 12 Volt

the V-200L 12 Volt

Dimensions (Width x Height) - 5

They allow for the use of one or more batteries in systems with one or more engines and facilitate putting batteries in parallel for emergency starting when one or both batteries are substantially discharged

The SmartShunt is a good alternative for a BMV battery monitor

ProMariner Battery Isolator - 2 Alternator - 3 Battery - 70 AMP [12073] import_2022_09_19_071223 the V-200L 12 VoltBattery Isolator 2 Alternator 3 Battery 70 AMP ProMariner Battery Isolators with gold plated terminals and improved efficiency, provide enhanced charging. Rated for use with DC devices ranging from 10 amps to 70 amps. Owner's Manual (pdf)