In my quest to disable battery charging from the grid, I was playing around with NodeRed and found these 2 options inside the Custom Input and Custom Control.
Max Charge Current output to debug shows 66-68 (amps presumably)
ChargerIsDisabled debugs 0, or false, as expected.
sending an inject to either with a valid input 0-120 or 0/1 is immediately overwritten with the original value shown.