A newbe LIFEPO4 questions on mis matched batteries

[Joe_]

I was reading through the manual on the EG4 power pro battery.
it states:

“Do NOT mix EG4® WallMount 280Ah batteries with any non-280Ah lithium batteries. This will void your warranty.”

I bought a pair of these for my system. When I choose to expand my battery system down the road what are my options?
Let‘s say as an example I want to build another battery to use on this setup using 320 amp hr cells.
Must I isolate it and either run off of it or the EG4’s. Why does it matter if the cell size of the entire battery is not the same if each battery under control of it’s own bms. I’d really like to understand this.

 

[SeaGal]

If batteries are of the same chemistry and cell count, there is no fundamental reason why they cannot be paralleled. However, in most cases, you will need to establish some comms between the battery and inverter (typically via CANBus or RS485). To do that you will need to use the same battery supplier for the comms to be synchronised between batteries and the inverter, as different suppliers use different versions of their comms protocols.

I would have expected that within EG4's range you could mix-and-match different Ah versions, but that is something you'd have to raise with their tech support.