Mine was more like 11.1/2 as seen on the Trimetric (not quite the same as at the inverter) ISTR.
My latest set-up with another inverter had a high alarm voltage which was confusing, but eventually I found the culprit.
It was where I joined two shorter wires lug to lug to get a long enough wire, and the joining nut and bolt was a bit loose, as discovered by how it heated up so much. Took me a while to accidentally discover how hot that was there. ( You can IR your set-up if you are keen, and avoid such things lasting so long.)
Wire gauges were ok; it was that bad connection. All good now.
