Growatt SPH with Grid-tie inverters?

I currently have two Grid-tie PV inverters, I'm looking to add a Growatt SPH 5000BL-UP as battery only and wondering if it will play nicely with the PV inverters?

I have a single grid-tie inverter and using a sph5000 with panels & a couple of batteries, it will charge the battery from the output of both inverters (dc from the growatt and it will use the ac from the other brand inverter).

Are those the high voltage batteries? I was reading some of the manuals from Growatt talked about a HV battery.

cyberdiamond said:

I have a single grid-tie inverter and using a sph5000 with panels & a couple of batteries, it will charge the battery from the output of both inverters (dc from the growatt and it will use the ac from the other brand inverter).

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I want to do the same. Is it already working for you?

I am not sure what you are dreaming of but the truth is:

SPH is a hybrid connected to a battery and

all other grid tied inverters are running independently from the SPH Hybrid in general

EXCEPT 1 point which is a more complicated one so be carefull:

SPH4600 is limited on the DC side from and to the battery to 3000W

If you are adding now 2 MIN 4600 single phase inverters (we have 8 growatt inverters) and winter might be there
then the 5000 or 6000 Wp panels connected to the SPH4600 might deliver 2000W - and not 3000 W, the maximum charging speed.

And now - only in these cases where the battery is not full and the panels from the sph are not delivering 3000W but maybe 1500 W - there can be a tweak set up if you have a 3 phase smartmeter as you always should just to be on the safe side for the future.

Now let us imagine the SPH gets 1500 W from the panels, pushes 500 into your home grid and 1000W into the battery while the 2 MIN 4600 produce 3000 W and supply the home with 1000 W and export maybe 2000 W into the grid.

This would mean 4500 W DC are coming from the panels and will be used
2000 W feeding into the grid
1500 W for appliances at home
1000 W charging

Your 3 phase energymeter should now measure 2000 W surplus and then the SPH 4600 could push its charging up to the 3000W charging limit by generating 2000 W DC by taking up to 2000W AC from your home net to reduce the export to 0 W.
In this case the MIN 4600 will indirectly supply the SPH via AC with 2000W AC which the SPH will use to convert it into 2000 W DC (minus losses) to charge the battery. The situation would be
0 W feeding into the grid
1500 W for appliances at home (from all 3 chargers)
3000 W charging SPH only

There is nothing more to achieve then that cause the bottleneck in the SPH single phase series for low voltage batteries has always been the limited charging / discharging capabilities up to 3000 W in general and 3300 W for a short boost of 10 seconds or so.

Final tweak would be to reduce the SPH AC generation to 0 W to use his 1500 W DC fully for charging and only taking 1500 W AC from the grid just to reduce the losses in total cause the SPH would lower the additional ac conversion from 2000W Ac to 1500 W AC while increasing the DC charging from 1000 W to 1500 W without losses.

I bet most of you will not have thought about this way but it all depends on the 3 phase meter and its measuring.
In any other case for example the SPH 4600 is already charging the battery with 3000 W you would need a separate AC DC battery charger.

And in case you will need more than 3000W in the evening you would also need an inverter for battery discharging into AC - or abuse a MIN4600 with a switch by connecting the solarpanel input with the battery, but be carrefull with that cause many things can go wrong and you would need a boost converter to get from 48 V battery voltage to the start voltage for a min 4600 which is about 150V or so.

MIN4600 and others are much cheaper but these are no hybrids so be aware of the bottlenecks which means slow discharging and charging.