I'm planning my victron setup, and am thinking of buying two multiplus ii units.
My normal power draw is usually well below 5kw but at times when I do cooking and switch on the immersion heater, it would for short periods go over 5kw in which case power assist would kick in. So is it possible to use a second multiplus ii just to kick in when demand is higher than what the first inverter can output? I'm thinking that this would reduce idle consumption if the 2nd unit is off most of the time.
This would double your idle consumption, as then you'd have two units idling.
MultiPlus units (including the -II) can be installed in parallel "stack" configuration for increased output, in accordance with the manual (and all associated documents linked therein) here: https://www.victronenergy.com/live/ve.bus:manual_parallel_and_three_phase_systems
But, as mentioned, this would double your idle consumption rather than lower it, since obviously both units must be "On" in order for the system to function.
The issue, of course, is that an inverter/charger is not a generator. For that, perhaps it would be better to install a generator.
Off Grid Garage did something like this but with a Phoenix inverter.
Connect any Inverter to the Multiplus in SERIES. Here's the comprehensive test and set up!
Which multiplus are you considering and in what setup?
Power assist supplements grid by using the batteries. If you're planning on a 5kW multi, you may find it has sufficient reserve.
Also be aware of the difference between Watts and VA ratings. It very much depends on your loads and with poor loads, output may be less than you expect.
Probably best to discuss with an authorised dealer.
I used this setup (2nd Multi as Generator) for over a year and worked perfectly.
Recently I programmed both Multi's to parallel and like it more than in series.
A parallel setup is much quieter, as they share the loads. And visibility in VRM is better.
