All battery types lose power and capacity as they age. The rate of when this happens depends on the maintenance of the battery and how it has been used (or abused). If you notice your battery just doesn’t have the same “umph” as it used to, it might be time to replace it.  In the cold this issue is more prominent. If you notice the battery is “swollen.” As the battery ages, gases can build up inside the battery and make the battery look bulging or swollen. The gases are not dangerous or have any safety issue, but the pressure can puff the case. If the battery is left in a discharged state and then very quickly charged, the cells can puff causing the case to look bulging. The battery will not hold a voltage above 13.28V for the 12V vehicle applications or 26.56V for 24V vehicle applications. The fault light is solid or flashing on the battery models that have the LED alert and is consistently on for days.