Can Growatts/MPP AIO inverters not in parallel mode share 48v battery banks?

[BrickedKeyboard]

So I noticed many people complaining of bugs in parallel mode, and I noticed it requires a rat's nest of wires and setup. (for both the MPP and growatts brands)

So I thought : why not use a large 12k watt split-phase ffor the 'main' house inverter, and put the EV charger on a separate 1 breaker subpanel. It's not even hard just move the wire over a few inches to a different subpanel, they are $25.

Then use a separate 240 volt only 5-6k watt AIO inverter with it's own solar string.

So you have 2 different inverters, they don't talk to each other, they have their own solar panels, and each is charging or pulling energy from the same battery bank.

Will this work or is there a 'gotcha'?

 

[Rednecktek]

There's no reason it wouldn't work, it's just like parallel charging since they don't talk to each other. The only concern would be the operating/standby draw of 2 units and having enough panels to keep the bank fed.

 

[BrickedKeyboard]

There's no reason it wouldn't work, it's just like parallel charging since they don't talk to each other. The only concern would be the operating/standby draw of 2 units and having enough panels to keep the bank fed.

Thank you. My only concern was that each inverter may believe the bank's state of charge is different than reality because each doesn't know of the charging/discharging done by the other.

Probably this is one of the reasons for the RS485 communication with the batteries that's more or less standard. If each inverter reads the SOC from at least 1 battery they can pick the correct phase for charging from: [ (constant current), (constant voltage), (float charge) ]

 

[mesquito_creek]

Thank you. My only concern was that each inverter may believe the bank's state of charge is different than reality because each doesn't know of the charging/discharging done by the other.

Probably this is one of the reasons for the RS485 communication with the batteries that's more or less standard. If each inverter reads the SOC from at least 1 battery they can pick the correct phase for charging from: [ (constant current), (constant voltage), (float charge) ]

I think you could use a couple of buss bars to isolate a shunt in between the battery buss bar and a battery distribution buss bar to the inverters. The shunt would be measuring total in an out of the battery bank before the split buss to the inverters.

 

[BrickedKeyboard]

I think you could use a couple of buss bars to isolate a shunt in between the battery buss bar and a battery distribution buss bar to the inverters. The shunt would be measuring total in an out of the battery bank before the split buss to the inverters.

This would work, do these AIO systems generally have external shunt support? For the bus bar/racks that Signature Solar cells yeah you could hook all your battery supply cables to the lower part of the bus bar, and the inverter draw cables to the upper part.

 

[mesquito_creek]

This would work, do these AIO systems generally have external shunt support? For the bus bar/racks that Signature Solar cells yeah you could hook all your battery supply cables to the lower part of the bus bar, and the inverter draw cables to the upper part.

The Victron shunt for example is a stand alone device. There is no communication between it and the mpp/growatt. I use a victron shunt with my mpp solar lv 6048. I have an old phone in my solar shack sort of permanently dedicated to the bluetooth shunt. I have to physically walk in there a check things out. My solar shack is too far away from my dwelling to blue tooth over to it. If your shunt will be within range of your phone most of the time you could just check SOC separately on you phone when inclined.

When I was first tuning my system I watched my SOC for days on end like a stock ticker... now I hardly pay any attention to it.

 

[BrickedKeyboard]

The Victron shunt for example is a stand alone device. There is no communication between it and the mpp/growatt. I use a victron shunt with my mpp solar lv 6048. I have an old phone in my solar shack sort of permanently dedicated to the bluetooth shunt. I have to physically walk in there a check things out. My solar shack is too far away from my dwelling to blue tooth over to it. If your shunt will be within range of your phone most of the time you could just check SOC separately on you phone when inclined.

When I was first tuning my system I watched my SOC for days on end like a stock ticker... now I hardly pay any attention to it.

Ok so it's doing the same thing for you you could get direct from the battery if you are using the type with a BMS interface. I was thinking in terms of the charge controllers doing a high voltage disconnect due to the voltage rise caused by the *other* charger.