Wiring batteries together to be shared by two parallel inverters.

[William.R]

Our current system is two 12Kpv inverters wired in parallel. Each inverter is connected to three 280Ah wall-mount batteries as well as 6.8kw per mppt.
It looks like the batteries of the secondary inverter do not discharge as much as the batteries connected to the primary inverter.
To solve this issue, we would like to combine all six batteries and have the inverters connect to this bank of batteries.
I have asked our vendor, and they told me they don't know how to wire this and to contact EG4 support.
Many emails have been sent to EG4 requesting guidance, but they have not responded.
My questions include: how will the communication wiring look, and do we simply connect the primary battery of each set of three (which is now connected to its respective inverter) to two new external bus bars (- & +) with the inverters connecting to these bus bars?
Also, does anyone have a contact for someone at EG4 who would be knowledgeable about such a topic?
Thanks...

 

[Hedges]

I might connect all six batteries in parallel, one inverter to diagonally opposite ends (+) one end, (-) the other end, other inverter the other diagonally opposite pair. Purpose is to make path from any battery to the inverter similar resistance to balance current draw. It is not perfect with long daisy chained power bus. There are other ways for 2, 4, or 8 batteries that would be perfect.

That would probably come out with shorter cables if these were six stacked server rack batteries. Being wall mount I suppose longer cables.

Ahh, communications. If the inverters are stackable, should be covered in their manual. I use a different brand but all inverters daisy-chain with RJ-45 cables and last one daisy-chains to a master JK BMS. The other BMS are NOT daisy chained by same cables, rather a JK-only bus, different set of RJ-45 jacks, is daisy-chained. Your battery documentation or inverter documentation should cover.

 

[William.R]

Thanks for the response, Hedges.
Does anyone have a contact at EG4 who is knowledgeable about wiring six batteries with two inverters so that we can enable the Share Battery setting?
I cannot get any response from EG4 support.