How old is your Atrix 2? If over a year then battery surely begins to give lesser performance. Disable any other task killer / memory manager & just let OS do its thing. See if installing Media Scan disable from play helps & do not keep using random chargers, make use of original charger as received with phone. Finally see Better Battery Stats. It is said battery stats should never be wiped but see if it helps you and finally search for Apex's better battery life guide for many handy tips.
I disabled notifications, sync, froze higher wakelock apps & my battery life improved a bit but then it is no fun existing in a bare bones environment.
Life is a bitch & then you die, still tryin to get a piece of that apple pie!
Rooted (One Click Method) ME865 running Stock JB 4.1.2 leak # 1 by wanggjghost - converted from originally Asia (India) MB865 (non At&t & non Lte) 1.2 ghz clockspeed & OC on fly using Tweakerz & CWMR using BMM 0.3.4 by Whirleyes & init.d support using 'apk based init.d by Ryu'