Eric007

As the graphs from SA( power vs soc) is a good indication of Master BMS disconnect.The SOC falling off the cliff with low load on the battery bank is an indication off master bms disconnect or communication failure between battery bank and inverters. Interrogate the master bms using Pbms tools V2.5 and have a look at the bms logs for the failure period.

I don't know how it works but it does 🙂 and attach an extract from Luxpower manual.
Well, each inverter manages its own battery bank and as for AC supplied to the load, it is split equally between both inverters (so if it shows the load is 15% of max capacity, (meaning more/less 2 x 5kW x 15% = 1500W) both inverters show 15% (ok, +/- 1%). I don't remember how it works with AC charging because I have not connected to Eskom in months but it worked until I added more panels and set myself free.
Also when I look at current to/from the batteries it is normally very similar (so if one battery shows, say, "-5A" the other batteries will also show more/less 5A flowing from other batteries).
I emailed Deye and will report if I get the response but it would be very disappointing If I had to have only one bank of batteries and had to use the same type/brand/voltage batteries to ensure communication... 
 

Why not?
My experience until now with two Luxpower inverters connected in parallel, each with its own bank of batteries is quite different. Each inverter takes care/manages its own battery bank. Why would Deye be different?  In fact the user manual for Luxpower inverter shows two setups for parallel operation: with a single battery bank feeding all three inverters and with a separate batteries for each inverter. And yes, each inverter has of course its own, separate PV cells (on both, Deye and Luxpower setup). I fully appreciate the single battery bank is more efficient (in scenario when specific inverter charged its own battery bank, its PV cells cannot charge batteries connected to another inverter). And then can think about other instances when having a single battery bank is preferred. But I'm willing to pay this price to be able to add more batteries in future if the need arises (and finances improve 🙂)
I asked this question thinking the answer is obvious but now I wonder...
 

Why not?
My experience until now with two Luxpower inverters connected in parallel, each with its own bank of batteries is quite different. Each inverter takes care/manages its own battery bank. Why would Deye be different?  In fact the user manual for Luxpower inverter shows two setups for parallel operation: with a single battery bank feeding all three inverters and with a separate batteries for each inverter. And yes, each inverter has of course its own, separate PV cells (on both, Deye and Luxpower setup). I fully appreciate the single battery bank is more efficient (in scenario when specific inverter charged its own battery bank, its PV cells cannot charge batteries connected to another inverter). And then can think about other instances when having a single battery bank is preferred. But I'm willing to pay this price to be able to add more batteries in future if the need arises (and finances improve 🙂)
I asked this question thinking the answer is obvious but now I wonder...