ABSTRACT: The research analyzes issues related to events that originate the behavior of a pacemaker battery in certain electro-electronic variations. Based on idea that pacemaker has the purpose of supporting the heart rate with electrical stimuli, the existence of errors in equipment's battery can lead to reduced autonomy and restricted failures that cause it to malfunction. The research process is based on bibliographic reviews and objective is to investigate cause of failure and explain in a technical way how this error can be minimized in order to reduce likelihood of these undesirable events in the equipment's operation.