DrainGuard is a new tool for Android phones which can track and monitor the battery draining out on standby on your phone. DrainGuard should help you to watch the consumption in standby, the time between a ScreenOff and a ScreenOn. DrainGuard informs the user when turning the display on about the battery consumption.
The free version has limitation that it can monitor the battery drain only from 100% till the time battery reached 70%.
More details and configurations available here.