NFC turned off, BUT still using battery

[BoboMan2]

Hello. I bought my Xperia Z3 Dual this new year. The battery performance was outstanding initially. It was giving me atleast 2.5-3 days on those initial extra usage days when there's excitement over a new phone. There was minimal drain during standby times. And I've always used lollipop.

Now, I notice a usual drain on my battery. Sometimes it stays on a certain level for a long time like 1-2 hours, but sometimes 2-3% fall right in front of my eyes. After waking up in the morining, it has fallen 5-10%. When the screen is off, I notice 2-3% usage. It is now giving me at most 2 days and I don't think I use too much of the screen like I did before.

I'm using constant Wi-Fi and GSM services (2G probably) in the mobile network settings. No mobile data connection, bluetooth, NFC etc. The only main apps installed are Whatsapp, Skype, Viber, Mimicker Alarm. I've tried out stamina mode as well with these apps in active standby, but NFC stays.

 

When I check in the battery usage stats, NFC service is on the top, even though I never use NFC and it is always turned off. 

How can I get rid of this NFC? I don't think I'll ever use it. 3 or more days battery is far more preferable. 

Thank you.

P.S I suspect that NFC service got here after I tried out "Smart Backlight Control" in the display settings. It was very convenient, but I immediately turned it off because I noticed NFC was turned on by its own. (I turned NFC off too).

[MarkMRL · Accepted solution]

There are some gaps in your battery usage graph. Are those intended (ie you rebooted the phone manually) or not? If they aren't them your phone is randomly rebooting on its own.

As for your problem with nfc, I'd try to run the phone in safe mode for a while and see if it happens. If it doesn't happen them it's one app you installed acting up. If it happens then you should try to repair the firmware using pcc and if it keeps happening then you may have a hardware problem. Also test if nfc actually works from the diagnostics menu.

[BoboMan2]

Thank you for the reply. Those gaps are ok, because I turned my phone off during the exams.

I'm now in safe mode and have noticed standby times are a little better (1-2%) fall in 1-2 hours, but considering there's no whatsapp working the problem might still be persisiting, as I also noticed a few more CPU usage seconds by the NFC service by itself.

However, I just performed the NFC diag test, and saw increasing NFC CPU usage in the battery usage. Then in the settings NFC was enabled! To check what had enabled it, I turned it off, and once again performed the nfc diag test, and this time the NFC remained off. So probably as I booted to safe mode, NFC was turned on by then?

Is the NFC test OK?

I'll get back to you if the problem is solved or not. Thanks.

[BoboMan2]

Hey! The battery seems stable in Safe Mode now. 

I just found out that HP Print Service Plugin app has permission to "control Near Field Communication". Could this be the problem?

Shall I force stop it (i might use it), or uninstall it?

[BoboMan2]

Thanks. After uninstalling HP plugin, i haven't seen the NFC service so far.