To the newer side (or older)? I about to engage in “dark voodoo” myself…
Plan to add some extra cable (AC) to the newer side.
Do battery cables need to be exactly the same length, I have a small space issue (newer cables may be 30cm longer than old)?
Bigger trunking and fold the slack back. AC and DC should be as symmetrical as possible. It always helps.
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It could be either. You have to engage that ohms-law part of your brain, and work it out by measuring voltage drops.
Or, if you root the GX, you can log in with ssh, run dbus-spy, and look at the /Devices/x/Ac/In/P, /Devices/x/Ac/Out/P, and /Devices/0/Ac/Inverter/P paths on the VE.Bus service.
First, what I would do is stop the hub4control service (svc -d /service/hub4control), and wait a couple of seconds so the Multi(s) goes into passthru mode. Then your input/output current is the same, and you can balance the input wiring until the current distribution is even.
Then drop the AC input power to put them into inverter mode. Then do the same with the output wiring while balancing the the Inverter/P power values.
Doesn’t have to be perfect, you just want them within 10% or so. If memory serves.
The number x in the paths will be 0 and 3, for two parallel units. The numbering is: 0-2 are the phase masters (in a three phase system), 3 is the first parallel unit on L1, 4 is first parallel unit on L2, etc. So in a single phase parallel system the units are 0, 3, 6, etc etc.
Edit: Probably do the output wiring first, then the input wiring.
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Would be great if there was a tool for that… 
If you press f on any item in dbus-spy, it selects it as a favourite. If you then hit capital F, it switches to a screen with all the favourites.
So simply select the paths you want to monitor, and then switch to the favourites screen. There is your tool 
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So how do you balance for interest sake - I don’t know if I will actually do this myself 
If more current flows out of the one unit (while inverting) than the other, then you need to add some cable length to increase the impedance. Similarly, if more current flows through one unit than the other (while in passthru and connected to the grid), then add more cable to increase that impedance. Once the two paths have equal impedance, the current divides evenly. The impedance of the transfer switch itself is effectively added to the input side cable.
Thanks - that helps… So I could shorten the cable on the “lower current” inverter to lower it’s impedance. (checking my understanding)
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This is quite interesting. I don’t want to intrude on this thread, but I tried this and in Pass-thru and I have about a 30W (530w vs 500w) difference between device 0 and 3 on both in and output. Inverting I have a 100W difference (600w vs 700w) How close do you need to have it balanced?
That sounds more than close enough to me. You really want to adjust wiring to get 50W to move over to the other side? I would not bother
That’s what I thought, but a confirmation is always welcome
I did the deed today. Multiplus II 5kv in parallel and doubles my inverter power for a very reasonable investment. Thanks @JacoDeJongh and @David@DBSEnergy (in Tableview)
@plonkster: I’m happy I think…
And: I learned a lot!
One issue I notice immediately is the extra grid feedback discussed here: Poor Grid Setpoint Tracking Multiplus IIs in Parallel
I have set my Grid Setpoint to 50w and this has offset things.
One day when I am brave I plane to look at the cable lengths of L1 In and L1 out to see if I can settle things down (1 day )
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