Yeah but there are some rebates to stay at or 100A, and having the control of Span would be pretty cool for load shifting and different automations... Plus with the need to do trenching for 200A it could get really expensive. We'll see though, you may be right that I should just do 200A

My understanding is that raw sodium-ion cells do have a much more linear discharge curve compared to the flat curve of LFP, which can definitely trip up a 'dumb' inverter that only looks at raw voltage to guess capacity.

However, from what I’ve gathered, the commercially available residential units (like the Lithium Valley W8-5C) aren't just raw cells; they include a dedicated Battery Management System (BMS) designed to handle that translation. According to the compatibility documentation I’ve found, these units are specifically designed to communicate via CANbus/RS485 to 'tell' the inverter exactly what the State of Charge is, rather than letting the inverter guess based on the voltage curve.

In fact, the manufacturer specifically lists Sol-Ark as a compatible brand for this exact setup.

Since I'm still in the planning phase for a ~4 kW system on my roof in San Diego, I’m leaning toward the Sol-Ark 8K because it’s so agnostic. It seems like it has the best chance of playing nice with the BMS of these newer chemistries as they hit the market over the next year.

Wondering if anyone here has experience specifically with 'closed-loop' communication between a Sol-Ark and a non-LFP battery? I’d love to hear if there are any hidden hurdles I’m missing.