I’m installing a Victron Orion XS 12/12-50A to charge my LiFePO₄ house bank from the engine start battery (Volvo Penta alternator via Volvo distributor).
My question is simple:
➤ Should the Orion XS be installed before or after the engine battery switch?
And related to that:
Is there an official Victron recommendation for either option?
What are the practical advantages or disadvantages of placing it before vs. after the switch — especially in marine systems?
I like to have the Orion to remain visible on the Cerbo GX, even when the engine is off. But I also want to avoid unnecessary standby drain or compliance issues.
➤ Clear answers or references from Victron documentation would be greatly appreciated.
Form a safety point of view, the BATTERY ISOLATOR switch should be exactly that. There should be no equipment connected on the battery side of that switch.
However, sometimes there are bilge pumps connected on the battery side. This breaks the rules, in that if there is an electrical fire, there is no longer a single switch to remove the source of energy which (may be) feeds the fire.
This switch is normally left on when the boat is in use, even if the engine is off. The should be a separate ignition type switch for switching on engine instrumentation and alternator field coils.
So the Orion should be on the battery side of the isolator switch, but on the battery side of the ‘ignition’ switch.