Android 5 has ruined my phone

[Sland]

I bought the Z1 Compact because the battery life was amazing.   At the end of a day (about 7pm) I would still have over 60% battery life.  Since upgrading to Android 5 my phone is worse than an iPhone, I am down to about 30% by 5pm.  I have pressed the orange button by the sim, I have enabled every power saving option going apart from the ones that completely castrate the phone and there is no improvement.  Not only that but it seems to only run 1 core of the CPU making it completley sluggish and frequently non responsive.  Android 5 an upgrade?  No way it is 10 steps backward.  Please provide detailed and accurate instructions to allow me to revert to 4.4.4.

[cobbler]

Oh dear, although I can't say that I'm surprised, I could be wrong but I think that you would require to root your phone to go back to Kitkat.

I like this phone too because of its good battery life, but I am staying with Kitkat purely because it works a treat.

[Uliwooly]

You don't have to root to flash your phone @cobbler

[Uliwooly]

@Sland

before downgrading reinstall lollipop with PCC > make sure to delete everything on the phone then wait couple of days, your battery life will improve

PC Companion (PCC)

Bridge (for Mac)

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355

[Uliwooly]

If you must downgrade 

/t5/Xperia-Z2/How-to-manually-update-downgrade-root-2014-Xperias/td-p/593459

@Sland

[cobbler]

@uliwooly So flashing the phone enables it to be downgraded then?

I thought to flash the phone needed to be rooted?

[Uliwooly]

Flashing the phone will update or downgrade the phone. rooting it's different. 

[cobbler]

Both ruin the warranty so never advisable.

[Uliwooly]

@cobbler

That's not true, in some cases it could. 

[sakis1981]

I think that you have a problem with your phone because I have the same phone and I am satisfied with the performance and battery after the lollipop upgrade!some times my phone last more than before!