Against my better judgement ...
Bottom line is lithum batteries are strange animals. Anything around 13.4-13.6 volts on a standard voltage display is probably 100% full or very close. Or not?That's part of the fun of lithium batteries, the "not knowing" your exact SoC.
If I see my Zamp CC tell me that my batteries are FUL, they're usually somewhere near 13.4V - 13.6V. The One Place display is usually close to these numbers, or maybe 1/10 volt lower. Once again, I'm good with "close". I am not a battery/off grid power micromanager. If stuff works on 12V, I'm happy.