Change to Lithium-ion?

I think the WFCO bashing has gone too far. They have an undeserved bad reputation because they are rarely installed correctly, and a very deserved bad reputation from a horrible reliability history that can be traced to poor physical layout of the components. When sized correctly for the battery bank and connected to the batteries with wires that aren't pathetically undersized, the WFCO loaded sensing technique for SOC is more accurate than the no-load voltage sensing of the competitors, and the current-based fan operation anticipates the cooling need instead of reacting to it. The WFCO converters I've had supply their full rated output with marginal AC input, while the PD converters I've had taper their output if the waveform and voltage aren't right at the upper end of the specs.

If they'd fix the reliability issue and emphasize correct installation I think the WFCO converters would be the pick of the litter among the mainstream power converters.