The wonders of Android 6.0 (Marshmallow) battery saving

My Nexus 7 (2013) got it’s Android 6.0 (aka Marshmallow) upgrade two weeks ago. One of the features of Android M was improved battery life. After multiple reboots, app upgrades, etc., here’s what it looked like:


Of course, that seems totally wrong – before the upgrade, I was getting about 2 days worth of morning/evening use out of it. Now this? Google helpdesk (yes, there is such a thing) couldn’t offer much:

  1. Boot into safe mode – did that. Turning off all possible apps does wonders to battery life (hint: it increases), but also does wonders to utility (hint: with nothing to use it for, no wonder it lasts for a long time).
  2. Inspect your apps and remove the ones that are gobbling up battery life.

The latter is, of course, the right thing – but the diagnostic tools are utterly lacking. The image only shows the app “Wifi”, followed by a bunch of OS-level apps that cannot possibly be uninstalled. And are probably not the cause of the battery drain. So other than painfully uninstalling a package, waiting for a few hours to see what battery life looks like, then re-installing (or not) and proceeding to the next app, there really isn’t a good way to do that.

Well, after several rounds of that, I *did* find the culprit – Messenger, apparently, was not behaving nicely – despite an upgrade. What did solve it was an uninstall-reinstall (plus subsequent re-configuration!). After that, battery life looked like this:

Crux of it: debugging battery life problems is utterly useless in Android M. So as long as your apps conform to the new Android M programming guidelines, you’re fine – and otherwise, you’re out of luck and hopefully have good IT debugging skills.

Oh, and did I tell you that the OS also doesn’t provide much in the way of diagnostics of apps that require certain permissions, but don’t automatically have them under the fine-grained (and arguably more secure) Android M model?

So, battery saving: A, user friendliness of upgrade: D- (I’ll give it a few points above F because upgrading was easy…).

#6.0#Android M#battery