limited battery voltage to two decimal points

lib/Battery/battery.cpp

@@ -28,6 +28,11 @@ void Battery::loop() {
     this->lastMillis = millis();
 }
 
+double Battery::getBatteryVoltage() {
+    double res = this->batteryVoltage;
+    return (int)(res*100+0.5)/100.0;
+}
+
 double Battery::readInputVoltage() {
     // Reference voltage is 3v3 so maximum reading is 3v3 = 4095 in range 0 to 4095
     double reading = analogRead(this->pin);

lib/Battery/battery.h

@@ -64,7 +64,7 @@ class Battery {
          * 
          * @return double in Volt
          */
-        double getBatteryVoltage()    {return this->batteryVoltage;}
+        double getBatteryVoltage();
 
         /**
          * @brief Get the charge level of the battery