It depends on the type of phone you have to be honest.
High grade androids have great battery life while low grade, budget Androids barely last a few hours.
My suggestion to you is to download 'Juice Defender'. Its an app which can drastically save your battery life if you know how to
use it right.
There are also a few simple other things you can do
-Turn down your screen brightness, also disable auto brightness
-Turn off features like WiFi and Bluetooth when not in use
-If you're not using your phone, turn off the screen-don't keep it on
-Don't allow apps to auto update without your permission or your Gmail/Email account to automatically refresh and collect new mail.
-You could try root your Android to give you more control over your device
Just a heads up, you might also have apps running in the background without your permission. If so, I suggest you download an App Killer to stop them.
Hope this little rant from me helped. I used to own a rather bad Android which had a lot of battery issues too so these tips that I listed for you were really what I did to lengthen my battery life each day.
If you want really good battery life and are still not pleased with the results after trying my suggestions, maybe think about purchasing a high grade phone (Samsung Galaxy s4/Note 3, HTC One Etc)
If you already own a high grade Android then maybe it's your battery itself which is the issue. If thats the case, think about buying a new one.