I bought a brand new Nokia Asha 501 Dual SIM and because I wanted to have a fine control of the amount of battery charge available at the moment, I developed a simple app just to read the value from the system, and show it in a Label. I am getting the property value calling the following API: LocalDevice.getProperty("com.nokia.mid.batterylevel")
However, the values I get are not progressive. The phone stays at 100% for about 2 days and then drastically drops to around 75%, and after another 2 days (aproximately) it drastically drops to around 50%, and then 25% and finally 4% when the low battery indicator and message is shown. I believe that the battery life is normal (about 1 week, aproximately), but I can't control the time to know when I should charge the phone. When the low battery sign appears, I have maybe 3 or 4 hours left of battery charge, and if I could know prior to that moment that the battery is around 15%, for example, I could charge it, because I knew that I won't have enough battery from there on.
Is this the right property to read the battery charge level? Am I using the correct way to do this? Is it recommended?
Thank you for reading this, and maybe help me with this issue.