Are you running a 48vdc system?
Battery prices are coming down, I just got some 100ah units for 320.00 and free ship... good BMS boards but they lack low temp shutoff.
Was going to buy 400ah rack-mount batteries but they were always out of stock.
NET: Ours is a commercially supplied system with Enphase controllers/combiners, and LG panels. 240V. 10 kWh battery. IQ7+ inverters all around.