Bad battery life after unlock bootloader??

Hello,

I created a backup from my TA partition, then i unlocked my bootloader.

After that i installed a recovery and then CM, but the battery life was so bad i wanted to go back to stock.

So i restored my TA partition and used FLashtool to install stock rom.

But my battery life now is very bad. I got like 2.5 hours on screen time...

Can somebody tell me what i did wrong?

Thankss.