Bloody typical that it would happen to me, but having done some research, I know that I am not a unique case, there are many reports all over the internet of it happening.

Makes me laugh that an update designed to fix bugs has caused me issues when I had none before.

I'm not seeing this either on my Nexus 5, must be something on your phone or your settings maybe????

Not everyone with an Xperia Z had the problems either, but plenty do. Xda-developers has many threads about it, and no doubt there are similar ones for the Nexus 5 now.

So, it's very odd and not clear what causes it. Obviously not everyone is disabling the location services and Google Now.

There's one key difference though. This is 4.4.3 on the Nexus 5 that has problems, but on the Xperia Z it's the 4.4.2 update that introduced the problem. Seems the problem is not so much with the OS update, but Play Services.

To be honest mate, I really don't see how. I rarely ever install any apps or change any settings, so unless the update changed a setting on its own then I doubt it... And if it did then surely it would be a simple case of changing that setting back to fix the problem.

Fact is nobody seems to know what causes it. I have wiped the cache, and it's perhaps better but too early to tell really. The next thing to try will be a factory reset which is a right pain considering I've got everything how I want it and really can't be bothered re setting everything back up.

Clearing the Play Services cache only seems to work for a short time.

A factory reset is always a time consuming PITA. Last resort stuff.

I've not noticed any difference on my N5 either after the update. Good or bad.

Well I've only had mine since Saturday. It was half full but charged it sunday and didn't need to charge until tues. That was with very limited use. But charged it Wednesday at 5pm and didn't use it and in the morning it was down to 72%. Battery went completely flat at 4pm. Not sure if thats normal or not though or if I've got a faulty phone.

I never saw any significant battery drain when I upgraded the other week but this week it drained very quickly. It said the screen was using most which is strange as never used it any more than usual.
I checked apps running and saw that Google Play Music was running even though I never use it. I disabled this and it seems to hold its charge. May be a coincidence but its still holding better than before.

Wiping the cache from recovery, at this point, seems to have helped. 2 hours 7 minutes and with 19 minutes screen on time, it was 94%, which is what I'd regard as acceptable. I think that would have been down to about 85% before the wipe.

v4.4.4 installed this morning

on 4.4.2 mine lost 1% per 8 hours overnight, on 4.4.3 it loses 2% per 8 hours overnight so not much difference to be honest (WiFi on with emails syncing etc.)

I'd love to know how some phones can manage only 1% drop overnight with all of the radios on, not even sure mine would have ever managed that even in airplane mode.

Anyway it seems to be back to a sensible level since u speed the cache partition. Although with 4.4.4 allegedly around the corner it looks as though even Google acknowledge that this wasn't a good update!

not around the corner.
it's turned the corner and is available.
installed on mine this morning.

I never seem to get my updates early so no doubt in a week or two it will land...

Edited to add just looks like a security update for SSL anyway so I won't get my hopes up.

easy enough to manually sideload it if you want.

My note 3 loses about 2% overnight but then it's got a massive battery.

Why is mine still using my mobile data even though im at home on wifi?

I have never had mine use cell data when it should have been on wifi. my old phone did it all the time.

i don't know. why yours is doing it. wifi is set up? enabled? you don't have some kind of battery saver app?

No. My data was on 4.95mb when I looked yesterday yet now it says 9.24mb used. As measured by my phone. Your carrier's data usage according may differ.

The new Three app can, and does, use mobile data even when you have WiFi enabled and connected. Is this a new feature of Android?

Useful as it is to enable the network to identify the user, what's to stop other apps using mobile data too? Is there a specific permission now for this?

Well im with talkmobile. Although I will be buying out my remaining contract and going to three.