Similar here. Early option seemed as battery efficient as suspend enabled, connected ok after 1h (1% battery drain in that time), after 4h too although had a strange behaviour in mc (2 seconds responsive, then ~5 seconds unresponsive, back and forth, mostly visible while scrolling in big directories), extra 2% battery rundown by this time. In the morning couldn't connect. After waking the device up it showed ~70%, not sure how but 20 minutes later checking emails/web browsing it was already down to 30%, evdev touch, msyncd and timed-qt5 in htop seem to have spikes in activity going 100% on both processors (actually over 100%/200% if you count all percentages of the processes, bug in htop?), don't remember such behaviour previously, could be related to the battery rundown. Needs more testing