I came across this inverter/charger while searching for a pure sine wave inverter solution for off-grid backup power. The unit is surprisingly solid. The unit is cabled to a pair of Walmart Everstart 24DC batteries. I watched the output waveform and voltage with an oscilloscope under 1.9 kW of resistive load and observed no distortion. Output voltage remained between 118-120 volts. Adding a light inductive load (300-watt fridge compressor) also caused no distortion. It's worth noting that the ground and neutral are not bonded, and you'll want to bond them for an off-grid install.
For kicks, I wired the unit to my 6HP 30-gal air compressor. The unit initially threw a low-voltage shutdown alarm and then worked on the second try. I was using a 6-ft run of 8 AWG battery cable, which was undersized for that load. I'm pretty confident the inverter would have handled that load with a larger battery cable.
The unit cannot be run in parallel with another and two cannot be used for split-phase 120v/240v operation because there is no mechanism to sync the output phases. Two minor negatives I discovered: The AC charger will not run at the same time as the inverter. This prevents plugging a generator for supplemental charging when needed, but could easily be worked around with a separate charge controller on the battery bank. Also the solar input has a maximum efficiency with an input of around 30 volts and a maximum input of around 80 volts. That limits us to shorter solar runs with thicker cables. Again, a proper MPPT charge controller hooked to the battery bank would be a workaround.
carole brown 
