 
   if (currentMillis - previousBattMillis > battInterval)
   {
+    previousBattMillis = millis();
+
     int battLevel = getBatteryPercantage();
 
     displayBattLevel(battLevel);

{
  unsigned long fermentationDelta = fermentationStartTime - fermentationModeStartTime;

  tft.setCursor(0, 40);
  tft.setTextSize(2);
  tft.println("Time to fermentation (hours)");
  tft.println(fermentationDelta / 36000000.00);


void displayFermentationHeading()
{
  tft.setCursor(0, 110);
  tft.setTextSize(2);
  tft.println("Fermentation Rate");
  tft.println("(in seconds)");
