Facebook has a lot of flaws but it is pretty great tool as well. On computer the flaws are not as bad. But if you have Facebook on mobile phone. You must know that Facebook and Battery are not the best friends.
However there are few improvements you can made. I have some tips for you. First of all you must go to settings and probably the most battery consuming are tips based on your location. And you never used them anyway.
And in the end autoplay eats awful amount of battery. Plus the easiest way how to safe battery if you have Android is simply to turn on battery saving mode. You are welcome.