diff --git a/src/WatchFeatures/Battery.cpp b/src/WatchFeatures/Battery.cpp
index 2bc0813..c3ff043 100644
--- a/src/WatchFeatures/Battery.cpp
+++ b/src/WatchFeatures/Battery.cpp
@@ -15,6 +15,7 @@ float WatchFeatures::Battery::GetVoltage()
 uint8_t WatchFeatures::Battery::GetPercentage()
 {
   float voltage = GetVoltage();
+  Serial.println(voltage);
 
   float level = (GetVoltage() - 3.6f) / 0.6f;
   if (level < 0.0f) {
@@ -23,7 +24,7 @@ uint8_t WatchFeatures::Battery::GetPercentage()
     level = 1.0f;
   }
 
-  level = 0.5f - sin(asin(1.0f - 2.0f * level) / 3.0f);
+  level = level * level * (3.0f - 2.0f * level);
 
   return std::round(level * 100.0f);
 }