Arduino Battery Capacity Tester

#include <StopWatch.h>

#include <Time.h>

/*
A battery life cycle tester using an Lcd as output
*/

// include the library code:
#include <LiquidCrystal.h>


// initialize the library with the numbers of the interface pins
LiquidCrystal lcd( 12, 11, 6, 5, 4, 3 );
int sensorPin = 15; // input battery sensor reading
int sensor2Pin = 14; // input voltage reading
int ledPin = 13; // output trigger for MOSFET/Transistor/relay
int sensorValue = 0; // this holds the value that the sensor reads
float LiMinThreshold = 2700; // Lithium Minimal Voltage for load removal
float LiMaxThreshold = 4200; // Lithium Max Voltage for load removal
float NmhMinThreshold = 950; // NMH Minimal Voltage for load removal
float NmhMaxThreshold = 1600; // NMH Max Voltage for load removal
float SelectedMinThreshold = 5000;
int BatVolt = 5000;
boolean done = false;
float mah = 0.0;
StopWatch sw_secs(StopWatch::SECONDS);




void CL2(){
  lcd.setCursor(0, 1);// Second line first char
  lcd.print("                        ");
  lcd.setCursor(0, 1);// Second line first char
}
void setup() {
  pinMode(ledPin, OUTPUT); // makes it so the IC knows this is an output pin
  lcd.begin(16,2); // sets up the LCD display, first is vertical pixel count second is rows
  lcd.print("Batt Test ON"); // prints a message to the LCD
  lcd.setCursor(0,1); //second line first character
  lcd.print("Det. Bat Type"); //print the voltage value
  delay(2000);
  lcd.setCursor(0,1); // second line first character
  lcd.print ("          ");
  lcd.setCursor(0,1);
  digitalWrite(ledPin, HIGH); // makes the MOSFET/Transistor/relay/LED on
  sensorValue = analogRead(sensorPin); // reads the voltage value from the sensor
  digitalWrite(ledPin, LOW);
  BatVolt = sensorValue*3.27*2;
  if (BatVolt > 4500){
    lcd.print("Too High");
    done = true;}
    else if (BatVolt > LiMinThreshold){
      lcd.print("Li-Ion");
      SelectedMinThreshold = LiMinThreshold;
  }
    else if (BatVolt > NmhMinThreshold){
      lcd.print("NiCd/Alk ");
      SelectedMinThreshold = NmhMinThreshold;}
      else{
        lcd.print("Unknown Bat");
        done = true;}
        lcd.print("V=");
        lcd.print(sensorValue*3.27*2); // prints voltage value
        delay(3000);
}

  void loop(){
    if (BatVolt > SelectedMinThreshold && !done){
      digitalWrite(ledPin, HIGH); // sets the transistor on
      sensorValue = analogRead(sensorPin);
      BatVolt = (sensorValue*3.27*2);
      sw_secs.start();
      CL2();
      lcd.print(BatVolt);
      lcd.print("mV ");
      mah = ((sensorValue*3.27*2/4.7)*(sw_secs.elapsed())/360); // this is the mAh equation I'm confused about
      lcd.print(mah);
      lcd.print(" mAh ");
      delay(40);
    }
    else
    {
      done=true;
      digitalWrite(ledPin, LOW); //turn the transistor/mosfet/relay/led off
      lcd.setCursor(0,0);
      lcd.print("Bat Tester Done");
      sensorValue = analogRead(sensorPin);
      BatVolt = (sensorValue*3.27*2);
      lcd.setCursor(0,1);
      lcd.print(BatVolt);
      lcd.print("mV I=");
      lcd.print(mah);
      lcd.print("mAh      ");
      for (int i=0; i<100 ; i++){
      }
      delay(1000);
    }
  }