Thanks Addison and auouymous.

However I don't use modest, metalayer-crawler is disabled and the drain also happened in flight mode (when ASUI was still installed).

So the battery itselft really seems to be the culprit. I had ruled out this option because

• It happens with two different batteries. None of them is new. One is a 2 year old Mugen, the other is an even older original Nokia
• Battery life is unsuspicious when the device is busy

But a bad battery is consistent with the observations that

• It started happening all of a sudden
• It happens with the vanilla installation too

So tonight a removed the battery and left it outside. In the morning I reinserted the battery, rebooted and the battery indicator had dropped from 7 hrs when idle to 5 hrs when idle. These numbers are not really consistent with the observations when the battery is in the device, but they indicate that the battery might discharge itself somewhat.

So I'll buy a new battery.

As a side note: with ASUI I did not manage to swich USB from HOST to OTG. It insisted on HOST. Does this ring any bells?