The BEP Marine 710-140A Digital Voltage Sensing Relay connects a second bank for charging at 140A, auto-ranging between 12V and 24V.
The relay connects the second bank only once the primary has come up to voltage, so the engine-start battery gets charging priority before anything else is brought on. That ordering is the whole point. A boat that charges both banks together leaves the starting battery short after a heavy overnight draw on the house side.
Against a diode isolator it avoids the charging-voltage drop those introduce, and it installs with a simple three-wire connection without altering alternator wiring. Separating the banks also keeps domestic loads off the starting battery and isolates sensitive electronics from starter-motor surges.
Digital circuitry keeps standby consumption low and selects 12V or 24V operation automatically rather than needing configuration. An optional remote-sensing connection to the ignition switch cuts standby draw further with the engine off, and a remote status LED output is available. Explore more bus bars and power distribution.
- Starting battery charges first, then the second bank
- Charging both together leaves the starter short
- No voltage drop, unlike a diode isolator
- Auto-ranging 12V or 24V, 140A
