Why is WiFi is draining battery even when it's off?

[AC Question]

I'm using a Nexus 5, I recently upgraded to Marshmallow. For 4 or 5 days now, every day, my battery has been going down a lot faster. I know that the Nexus 5 is known for bad battery, but this is really bad. So I went to the battery stats in settings, and found the Wi-Fi was actually using the most of the battery, with around 25-35% average per day. When I clicked on the graph for more settings, it said that the Wi-Fi had been on for almost the whole day, even when I was in school. At first I thought I just forgot to turn off Wi-Fi that day, but the second day, again, Wi-Fi was draining, and I had not only made sure I turned it off, but I even set a Tasker profile to turn off Wi-Fi off. Still, this problem persists. It is a bug, or is Wi-Fi just not turning off? Thanks.

 

[B. Diddy]

Welcome to Android Central! Does this persist after a reboot? How about a cache partition wipe? http://forums.androidcentral.com/nexus-5-rooting-roms-hacks/352008-guide-nexus-5-recovery.html. Be aware that the latter can take 5-10 minutes on a Nexus 5.

 

[anon(4086547)]

It's a bug in Marshmallow. Turn WiFi off and reboot the phone.

 

[PhiPsi32]

I've had a similar problem. I turn off WiFi, but it still drains the battery. Toggle WiFi on then of again. That seems to work.

I've also had that problem with GPS.

 

[mrbrock72]

My battery was running down much faster than normal and my wifi kept disconnecting and reconnecting every few minutes. I fixed it by going to Settings - Backup & Reset - Network Settings Reset. I then had to reconnect to my wifi and everything was back to normal.