battery consumption check for my app in iOS

I need to get battery consumption details for my app.
I have used instruments for tracking and i am getting energy usage level as 1/20.
What is this 1/20?

Shortly :

UIDevice *Device = [UIDevice currentDevice];
[Device setBatteryMonitoringEnabled:YES];

 int state = [Device batteryState];
NSLog(@"Now the status: %d",state);
 double batLeft = (float)[Device batteryLevel] * 100;
  NSLog(@"Charge left: %ld", batLeft);

The API allows you to register to receive notifications for changes to the battery level. It only reports a change at 5% increments up or down, but you can use a timer and measure the time between two changes (or initial battery level and first change). Here's how you register for the notifications:

   // Use this call to get the current battery level as a float
  // [[UIDevice currentDevice] batteryLevel]

   [[UIDevice currentDevice] setBatteryMonitoringEnabled:YES];

  [[NSNotificationCenter defaultCenter] addObserver:self
                                    selector:@selector(batteryStateDidChange:)
                                     name:UIDeviceBatteryStateDidChangeNotification
                                   object:nil];

   [[NSNotificationCenter defaultCenter] addObserver:self
                                 selector:@selector(batteryLevelDidChange:)
                                     name:UIDeviceBatteryLevelDidChangeNotification
                                   object:nil];

The first notification tells you the current state, e.g. unplugged, charging, or full. The second will get triggered whenever a 5% increment is reached.

Seems to me that if all you're given is change notifications at 5% changes up or down, accuracy is not something you can calculate very well or quickly. A 5% change could take a very long time if the device isn't doing anything.

Maybe you can monitor [[UIDevice currentDevice] batteryLevel] with a timer, however, while I haven't tried it I think it only gets updated at this same 5% increment.

From: iphone: Calculating battery life