I received two units; one failed straight from the box.
A third unit, ordered as a replacement, failed in the same way. There were no manuals included and I could not find support or documentation online. I have returned all three units.
I cannot recommend these products based on this experience. The only positives were fast initial delivery and a straightforward returns process with refunds, which is why I rated two stars. Plus only 12 months warranty.
I recomend Anker solix dc models.