MultiPlus-II ESS topology question

[Jimster (Jim Lyons)]

Hi,

I’m planning to use a MultiPlus-II 12/4000 in my motorhome.

When the van is parked at home, I’d like to use it as a portable battery to reduce grid import. My house already has a 2 kW grid-tied solar inverter.

I’m trying to understand the wiring.

Does a MultiPlus ESS always have to feed the house loads via AC Out, or can it operate in a parallel topology where it simply offsets grid import?

I’ve been reading the ESS parallel topology discussions, but I’m not sure if I’m interpreting them correctly.

Has anyone done something similar?

Thanks.

[lxonline (LX)]

If it is in a mobile installation ESS is specify advised against.

1. ESS introduction & features - 1. ESS introduction & features

Summary

That being said with ESS, any load on the output of the inverter has to be smaller than the inverting ability of the inverter or if grid connected smaller than the passthrough ability of the inverter.

The ideal set up is grid into the input - loads on the output with the exception of the use of an energy meter which allows some energy to be injected backwards.

With ESS you can export excess solar and sometimes battery to loads before the inverter (ac input) if there is a grid meter that communicates with the GX for the inverter at the grid or incoming side.

@Jimster

kW grid-tied solar inverter.

Since you also have this is would need a way to know about it as well.

[Jimster (Jim Lyons)]

the plan would be to only enable ess when the vehicle was docked at home.

[lxonline (LX)]

You would essentially be reprogramming it each time.
And also required to have a connection that is not unsafe both electrically and otherwise.