Using both generator and "grid-tie" backups

MiltonAdams

I am using dual Trace 5548 in series, giving me a 240v electrical panel and LiFePO4 48v batteries.

Is it possible to use one of the inverter’s settings to auto-start a 120-volt Honda eu3000 generator (which is working perfectly) AND use the other inverter’s setting as a grid-tie backup battery charger per the Energy Management Mode (p. 90)? (https://www.evernote.com/shard/s129/sh/945b67f6-4ed3-4b74-8922-2deedcbccd92/0d0bb36adc245f92e154f2f20d95f7fb)

If this combination is possible, what are the implications on page 97, under Automatic Generator Control with Multiple Inverters? It says,

 “Several considerations must be taken into account when using the automatic generator controlling system with multiple inverters. The invert that controls the generator – referred to as the “generator controlling” inverter – along with the other invert which does not control the generator – referred to as the “non-generator controlling” inverter – must be programmed differently to achieve the best results. The two inverts should be programmed with the same Bulk Volts DC and Float Volts DC settings but with the Absorption Time on the “non-generator controlling” invert to be a longer setting. This will ensure that the charge current is shared between the two inverters more equally during the absorption stage by preventing one of the inverters from switching to float before the other. When the inverter that controls the generator reaches float, it will shut down the generator.”

Does “best results” mean that the Bulk Volts DC and Float Volts DC (which I have set at 40v to essentially deactivate it with my LiPO4 batteries) don’t have to be programmed the same – it will still work with sub-par results? I thought the charging current, reference above, only goes through the inverter that has the generator physically hooked up to it. So how does it “ensure that the charge current is shared between the two inverters . . .”?

To complicate this scenario, my brother-in-law is staying with us for the winter while he builds a new home. He has temporarily set up 6 panels (about 2kw) to keep his lead-acid batteries topped off and occasionally supply his camper.

Our goal was to set up the Energy Management Mode (p. 90) as a “grid-tie” that sends 120 vac from his 120 vac inverter system to my inverter’s AC1 input. This would use his extra energy as a backup instead of using my generator. But I think I would need to set the Bulk Volts DC setting differently for both inverters, so his “grid-tie” is prioritized over my generator.