Disclosed are methods and systems to help conserve battery life of a user equipment device (UE). In particular, the UE may make a determination that a remaining battery life is threshold low. In response to making the determination, the UE may engage in a scanning-limiting process that involves (i) the UE identifying on the list each carrier frequency higher than the serving carrier frequency and (ii) based on the identifying, the UE excluding each identified higher carrier frequency from the list, so that, in response to detecting a trigger to scan carrier frequencies in search of target coverage for possible handover, the UE scans each carrier frequency on the list that is lower than the serving carrier frequency but forgoes scanning each identified higher carrier frequency. Further, once the UE detects the trigger, the UE may responsively scan carrier frequencies in accordance with the scanning-limiting process.