Google’s Android mobile operating system does not have a reputation of being rather reserved with the use of its resources, as there has been a bunch of issues that have impacted the eventual user experience already, ranging from battery drainage to memory leaks all this while. Hence, it is with a renewed sense of hope and optimism that users looked forward to the Android 5.x Lollipop update to deliver a far more polished user experience sans any kind of major issues, but it seems that even that wish is not granted with attention being pointed to the issue of battery drain by users.
At the Android Issue Tracker, there happens to be a thread that addresses this particular issue, and you can be sure that battery drain is no fun to live with at all. It leaves you on the constant lookout for a power outlet, and not only that you will most probably need to purchase some sort of power bank in order to ensure that there is an emergency supply of battery, just in case. So far, this thread which was opened in April this year has seen approximately 600 comments, and it seems that selected apps that rely on mobile data will not shut off the radio upon the completion of a download.
Hopefully Google will be able to fix this issue sooner rather than later.