I have the older LG CHem's unfortunately but with 2x expansions each so (2x 6.4, 4x 3.2)'s.. I would have preffered to have all the units in slave/master mode and just drawing from one core system, but after tests and assistance with SMA this is unsupported due to the Sunny islands only able to read from 1 battery bank. So i ended up with.
Phase 1 - Essentials grid
1x LG Chem 6.4 master unit
2x LG Chem 3.2's (expansions packs) so a total of 12.8kwh
1x Sunny Island 6
1x Sunny Boy 5kw
1x Sunny Boy 3kw
We have 8kw of panels on this section, split over 3 different panel strings (1 on top of shed) and then 2 seperate ground mount banks)
Phase 2 - Non-Essentials grid
1x LG Chem 6.4 master unit
2x LG Chem 3.2's (expansions packs) so a total of 12.8kwh
1x Sunny Island 6
1x Sunny Boy 5kw
1x Sunny Boy 3kw
We have 10kw of panels on this section, split over 3 different panel strings (1 on top of shed) and then 2 seperate ground mount banks)
Then i have a single 8kw Honda auto start generator connected to both units allows for timer controlled running, as well as backup capability, currently programmed if batteries drop below 10% it auto starts and charges to 40%. Runs very rarely.
SMA Cluster controller in the middle of all of it to help with control/monitoring capability.
And some Transfer/Phase switches etc so if i loose phase 1 batteries i can switch the phase to run off the second bank whilst repair first. Was implemented for full redundancy in the system, including loosing a SMA sunny boy (hence why there are 2 solar inverters in each) if one plays up (which it has in the past) the phase will continue to charge. Redundancy was a big thing for me, needed to ensure i had everything all ok to run.