Does a GROWATT SPH4000 charge with the AC from a second inverter if panels deliver less than the 60A max the SPH is capable ?

Am I right that in this case the SPH uses AC for charging when the 14 panels do provide less than its max. 60A ?

GROWATT SPH 4000: 7 kWp panels (2 strings 7 panels x 500W)
GROWATT MIC 3000: 3,5 kWp panels (7 panels x 500W)
TPM Smartmeter (3 phase smartmeter talking modbus to the inverter)

The SPH might get 100 A from its panels and therefore charges the battery with 60A (which is maximum it can) if 40A are needed for grid.
Now at 5 pm the panels provide just 55 A which then will force the SPH to draw 5A from the grid cause the TPM will tell him about the current fed into the grid every second from a 2nd inverter, maybe a Growatt MIC 3000 with another 7 panels each 500W

If the SPH gets only 40 A from the panels it will draw up to 20A from the grid if available to charge the battery ?
Is that right ?

Then the system would become more efficient as a whole cause for surplus feed into the grid I get only 8 Cent and for that I draw from the grid later I have to pay 38 cent, so it would make sense to use AC charging with even losses of 50% cause I would invest 1,5 kWh or 12 cent just to save 1 kWh later or 38 Cent.
26 Cent saved or won just by such a feature if I got it right.

Would it make sense to increase the battery from 6 kWh if 6 kWh is what is needed during long Winter evenings from 5 pm to 8 am ?
The AC charging will only kick in once the battery is not full so usually in late autumn, winter or early spring, right ?

List ALL your menu settings.

I am planning the system so menus will not really help I guess cause the first sph 4600 that had arrived was DOA

Replacement will arrive not before september and meanwhile I got a MIC 3000 as replacement to supply one string of 7 panels.


But I guess meanwhile I found out that the SPH4600 once connected to the 3 phase SMARTMETER TPM will recognice the power generatted from the 2nd inverter MIC 3000 that goes into the grid.
Then it will take the missing amount of A it needs to charge the battery with 60A, in this case 20A x 50V = 1000W from the house grid generated by the MIC 3000 inverter. The SPH will take such amount till it charges with 60A or till the feed in amount is close to 0.

how it charges depends on setting

set charge rate to 50a in menu
set charge priority to solar first

PV
full sun ->50a - has battery reached bulk/float/High voltage cutoff - no
alf sun ->25a has battery reached bulk/float/High voltage cutoff - no
1/4 sun ->12a has battery reached bulk/float/High voltage cutoff - no
dieing light ->1a has battery reached bulk/float/High voltage cutoff - no

dark - transition to grid charging
grid charge ->50a (or whatever menu setting its says) - draw from grid at this rate till battery has reached bulk/float/High voltage cutoff

Only solar - no grid charging

solar + utility - adds whatever utility side it needs to make it to the output charge rate you have selected (I think this only works while the sun is up)

note that max charge current is different from max utility charge setting, so you can set utility charge rate at something lower than max charge rate (which factors in useing all sources, this is usefull so you can charge off small generators at smaller charge currents, or to limit the amount of energy pulled from the grid)

utility first - charge from grid first and only use solar when grid is down.

You mean that utility is the home grid over which the 2nd inverter will deliver its power that otherwise would be fed into the grid, right ?

If solar + utility would only work while sun is then this would work pretty well cause right now we will get 3 strings of 7 panesl each 500W and the mic 3000 inverter could be very beneficial if the SPH 4600 charge rate goes below 60 A cause the MIC3000 could roughly add 50% of the energy provided from the first 14 panels.

And of cause the SPH would not charge the battery from the grid during night or early in the morning when the sun in winter is still weak.
thx a lot

I am seeing this happening with my system. I've only just installed the SPH 5000 on my shed (between the house and the grid). It's a cloudy day and as long as the house isn't drawing much, the house inverter is feeding that back to the growatt which is pushing the excess from the house into the battery (i.e. both the growatt's panels and the house's panels seem to be charging the battery).

This is unexpected and pleasant

I know this is happening because the growatt is reporting it's panels are generating only 500W, but it's putting 1,600W into the battery! I have the Growatt's CT meter downstream of both the growatt and the house inverter.

chopwood said:

I am seeing this happening with my system. I've only just installed the SPH 5000 on my shed (between the house and the grid). It's a cloudy day and as long as the house isn't drawing much, the house inverter is feeding that back to the growatt which is pushing the excess from the house into the battery (i.e. both the growatt's panels and the house's panels seem to be charging the battery).

This is unexpected and pleasant

I know this is happening because the growatt is reporting it's panels are generating only 500W, but it's putting 1,600W into the battery! I have the Growatt's CT meter downstream of both the growatt and the house inverter.

Click to expand...

But you need to use the CT meter right to get it right cause I had seen some who have gotten the 3 phase meter wrong and got wrong figures where the inverter did not react properly but only due to their installation mistake.

Yes, the CT meter needs to be on the grid side of both inverters. My system is single phase, so there would be complications for 3 phase.

its A/C coupled so any excess detected by the SPH / CT clamp will feed that charge circuit DC side, this could come from any other inverter upstream of the CT clamp

Hi, i have an hybrid Growatt SPH3000 single phase, with his CT (no smart meter SDM230) + 2x Growatt batteries GBLI 6532. I also have another inverter Aurora UNO 3,00kW connected to my house.
How can i set the Growatt to recharge the batteries by the exceed energy of the other inverter?
Ty to everyone