[Q] HELP: My experia z is experiencing a POOR battery life since installing a MIUI v5 topic

I noticed that my xperia z is experiencing a poor battery life since flashing a custom miui rom v5 on it. :( Im thinking of putting it back to a custom stock rom so that I can switch on my battery stamina mode. My xperia z wont last a day anymore since installing the miui rom. HELP please, what do you suggest for me to have a very long battery life even if I am with a miui ROM. I already put the brightness of my phone to a very low level and I already installed a greenify on it.