My primary inverter a Growatt "SPF 12000T DVM" is connected to some panels and 8x batteries "Growatt Hope4.8L-C1" via the battery terminals and the communication cable.
I also however have a 3 phase pump which I need to power and cannot easily replace with a 200v single phase pump.
Based on this requirement I was considering purchasing an additional 3 units of "SPF3000TLLVM-ES" in three phase configuration and connecting them to the same battery bank to use only as an inverter (no MPPT charge functionality).
After contacting Growatt they have told me it is not supported/recommended to connect additional units to my same battery bank, even if these additional all-in-one units do not have the MPPT connected. I also explained that of course the battery communication would not be connected on these additional units and a low voltage cutoff would be used to prevent over draining the batteries via the additional inverter units. They told me this was not recommended and might void the warranty, but the reason was not an inability to deliver the required current by the battery, they did not explicitly state it but I suspect the issue is is that they are concerned that the BMS on the "Growatt Hope4.8L-C1" batteries may not behave as desired if there is an unexpected current draw from the second inverter that it is not communicated to the battery communication port when the primary inverter has a communication channel open.
Does anyone have experience with such configurations of running a second inverter (or in this case three inverters for 3 phase) against a battery bank that is already connected to one inverter and operating with a smart communication protocol.
I think one possibility might be to have the battery array operate in dumb mode where I don't connect the primary OR secondary inverter via the battery communication cable and instead use low voltage disconnect and high voltage cut-off for both inverters to avoid any potential confusion. I am concerned though that I will lose the benefit of connecting the batteries together with the communication cable (self balancing perhaps?) if I don't connect the battery communication cable to at least 1 of the inverters. But perhaps it is the case that the batteries can communicate amongst themselves without having any inverter connected...
Another possibility would be for me to try and reverse engineer the battery communication protocol and insert a micro-controller inline between both inverters and the battery to act as a MUX and to try and aggregate current demand information for both inverters. This may be possible as I have already reverse engineered the PC based USB control software for the main USB port on the primary inverter to adjust settings with a python script.
Any information/insights or first hand experience would be very welcome even if it is with other batteries and other inverter types.
I guess I am most curious about what type of comms the all-in-one inverter units are doing with the batteries, and how likely it is that the battery would and up in a strange state if I attempt to run two different inverters off it with only one inverter connected via the battery communications port.
I also however have a 3 phase pump which I need to power and cannot easily replace with a 200v single phase pump.
Based on this requirement I was considering purchasing an additional 3 units of "SPF3000TLLVM-ES" in three phase configuration and connecting them to the same battery bank to use only as an inverter (no MPPT charge functionality).
After contacting Growatt they have told me it is not supported/recommended to connect additional units to my same battery bank, even if these additional all-in-one units do not have the MPPT connected. I also explained that of course the battery communication would not be connected on these additional units and a low voltage cutoff would be used to prevent over draining the batteries via the additional inverter units. They told me this was not recommended and might void the warranty, but the reason was not an inability to deliver the required current by the battery, they did not explicitly state it but I suspect the issue is is that they are concerned that the BMS on the "Growatt Hope4.8L-C1" batteries may not behave as desired if there is an unexpected current draw from the second inverter that it is not communicated to the battery communication port when the primary inverter has a communication channel open.
Does anyone have experience with such configurations of running a second inverter (or in this case three inverters for 3 phase) against a battery bank that is already connected to one inverter and operating with a smart communication protocol.
I think one possibility might be to have the battery array operate in dumb mode where I don't connect the primary OR secondary inverter via the battery communication cable and instead use low voltage disconnect and high voltage cut-off for both inverters to avoid any potential confusion. I am concerned though that I will lose the benefit of connecting the batteries together with the communication cable (self balancing perhaps?) if I don't connect the battery communication cable to at least 1 of the inverters. But perhaps it is the case that the batteries can communicate amongst themselves without having any inverter connected...
Another possibility would be for me to try and reverse engineer the battery communication protocol and insert a micro-controller inline between both inverters and the battery to act as a MUX and to try and aggregate current demand information for both inverters. This may be possible as I have already reverse engineered the PC based USB control software for the main USB port on the primary inverter to adjust settings with a python script.
Any information/insights or first hand experience would be very welcome even if it is with other batteries and other inverter types.
I guess I am most curious about what type of comms the all-in-one inverter units are doing with the batteries, and how likely it is that the battery would and up in a strange state if I attempt to run two different inverters off it with only one inverter connected via the battery communications port.
