Can't the 9V battery be rechargeable?
I have made 2 small voltage divider with a 4meg and 50k resistor both resistors are 0.1% 50ppc. I want to try the ads1115 across this to measure the R1. But I think I will need some filter and buffer stage in between to get some reliable result. Not sure if this is right though?
And yes I will use the 16bit code. Thanks for reminding.