I have not been able to either - seems they force it to be 100%
Of course charging to 100% is important to equalise cells, and being at 100% is not in itself that damaging, it is how it gets there what is important, the last 10% needs to be charged gently, and my Growatt inverter seems to do that correctly
I have also noticed I can't limit chrge rate, it seems to force 100% (which for my 2 battries is 4kW. I would have preferred to reduce that to 75%
