Q: I have some Bluetooth Low Energy beacons that help the phone deduce its location. I want my app to run in the background in Low Energy Mode, listening for messages sent by the beacons.I tried this on a Nexus 4 running Android 4.3 but It is consuming as much power as a regular Bluetooth connection would. i.e. I am not seeing any power savings on the phone. Is there a way to reduce power consumption?
A: As soon your device is running in scan mode, the power saving is zero. In scan mode the receiver is on and is looking for devices in advertising mode. In Android 4.3 you can´t split between scanning for classic BT and BLE. Classic BT is advertising on 79 channels with 1 MHz bandwidth and BLE is advertising of 3 channels with 2 MHz bandwidth. The listing of a dual mode device will charge more energy than listing in single mode (classic Bluetooth only). This is logical, because 79 chancels with 1 MHz plus 3 channels on 2 MHz is already scanning on 82 channels. If you have a good contact to Google or to some Android communities where Google is active reading the blog posts, then please be so kind and forward this link or whole text. We need the option to scan on the 3 channels for BLE only. Thank you in advance for wide spreading this message. For further questions drop an email to harald.naumann (at) gsm-modem.de .
Source: https://www.quora.com/Bluetooth-Smart-v4-0-Low-Energy/How-much-power-can-actually-be-saved-when-using-BLE-on-a-Phone