Overlander Monitor - varying power sources - ADC readings unreliable

Excellent. I remembered seeing similar code previously and found where you'd posted it previously to better understand the breakdown of your ratio 0.0002567. I noticed you previously had an Aref constant in your code, but of I understand correctly, now you're just calibrating that ratio when you test the ADC against a voltmeter? I've put my refined math code below. resRatio is (220k + 10k)/10k = 23, and I've used your Aref of 1.075. And the overvoltage you mention, with a ratio of 23 would mean that anything from 25.3vdc to 115vdc would be safe, but the ADC will just see the maximum value.

https://forum.arduino.cc/index.php?topic=442778.0

  total = 0; //reset total
  analogRead(pri_battPin);//one unused reading to clear any ghost charge
  for(int x = 0; x < 64; x++){
      total = total + analogRead(pri_battPin); //Add each value
     // pri_pinVolt = primaryVal * ADCratio; //ADCratiomV per 1024 steps for 5 Volts (ie; 5 / 1024 = ADCratio)
      //priBattVolt = pri_pinVolt * ratio; //grab the calculated under 5Volt input and multiply it by the ratio to ..........
      //priBattVolt = round(priBattVolt * 10)/10.0;
  }
  priBattVolt = (total / 64) * resRatio * Aref / 1024;

  
  total = 0; //reset total
  analogRead(aux_battPin);//one unused reading to clear any ghost charge
  for(int x = 0; x < 64; x++){
      total = total + analogRead(aux_battPin); //Add each value
  }
  auxBattVolt = (total / 64) * resRatio * Aref / 1024 ;
  

  total = 0; //reset total
  analogRead(solar_Pin);//one unused reading to clear any ghost charge
  for(int x = 0; x < 64; x++){
      total = total + analogRead(solar_Pin); //Add each value
  }
  solar_chargeVoltage = (total / 64) * resRatio * Aref / 1024;