#define battery A0

float bat_disc = 2.5; //Diganti sesuai spek dan konfigurasi battery
float bat_charge = 4.2; //Diganti sesuai spek dan konfigurasi battery

void setup() {
  Serial.begin(9600);
  pinMode(battery, INPUT);
}

void loop() {
  float bat = analogRead(battery);
  float voltage = (bat+1)*5/1024;
  float percentage = (voltage - bat_disc)/(bat_charge - bat_disc)*100;
  Serial.print("Battery volt: ");
  Serial.println(voltage);
  Serial.print("Battery percentage: ");
  Serial.print(percentage);
  Serial.println("%");
  delay(200);
}