For a marine application, does this charger provide any protection to a standard alternator from a sudden lithium battery shutdown by the BMS? I understand the charger can throttle the charging current to prevent alternator overheating. I am interested in the other boundary condition presented by lithium batteries: a sudden shutdown and disconnect from the charging circuit.
No, the Orion does not have this capability. Note that a BMS shutdown is an extremely rare event.
If you have the alternator charging a lead acid start battery and using the start battery as the input for the Orion, than the spike of a BMS shutdown will not be sensed by the alternator which will continue charging the lead acid battery.
The reply by @CharlieJ is correct, if you have the starter battery in circuit thsi will protect against the BMS shutdown. One correction though, he says IF you have the lead acid in circuit, the correction is you MUST have the lead acid in circuit, people who have connected the alternator direct to the Orion have suffered voltage swings because the 2 sets of voltage control do not work together, you need the battery to buffer / damp the system.
Thanks for making this clear.