help!!!!!! topic

i have nokia x2ds and i updated it from 2.1.0.11 to 2.1.0.13 then i found my battery life time not good The battery operated for four days now after update day and half or two days!!! I observed that the system would take out the battery 70 % to 18 % it is to much!! my phone not rotted and all settings is of galance and >>>>>>>>>>>>>>> all of this of sound no sim no messig it is wifi only and can i go to my last v 2.1.0.11 pls help me