I am sure it can give you better backup if you install battery doctor app from play store, I think asus built in app also has power saving mode too have you set that?
I have set the built in power saving app to optimized, but it is still not that effective, I guess it is only good for dimming the display based on the usage.
my biggest need is to have sufficient battery to get me through the traffic jams on the way home.. So will have to recharge for a while before leaving office.