I can see Seplos doing a bangup business with these new Mason stackable 280ah kits. Many folks have been moving towards server rack batteries from outfits like Signature Solar, but since these kits are very reasonable, well constructed, include an excellent BMS, and offer the same outcome as the rack batteries at much less cost, I believe they are one of the better solutions available on the market. Well done Seplos! You have filled a need. Buying the 280ah cells and the kit with BMS and putting it together provides 14.3KW per battery(using Signature Solar 51.2v calc), vs an EG4 @ 5KW.
SS EG4 = $350 per KW
Seplos Mason 280ah Kit= $147per KW
I know which way I will be going. BTW, my current DIY cost is $118 per KW, but no where near as pretty and fire resistant as the Masons.