One aspect of this disclosure relates to a system for dynamic battery management in implantable medical devices. An embodiment of the system includes two or more devices for measuring battery capacity for an implantable medical device battery. The embodiment also includes a controller connected to the measuring devices. The controller is adapted to combine the measurements from the measuring devices using a weighted average to determine battery capacity consumed. According to various embodiments, at least one of the measuring devices includes a coulometer. At least one of the measuring devices includes a capacity-by-voltage device, according to an embodiment. The system further includes a display in communication with the controller in various embodiments. The display is adapted to provide a depiction of battery longevity in units of time remaining in the life of the implantable medical device battery, according to various embodiments. Other aspects and embodiments are provided herein.