A power backup device charging system includes components coupled to a power supply system that is configured to supply power to the components, and a power backup device that is coupled to the components and the power supply system. The power backup device identifies a minimum power requirement for the components and sets a first charging threshold based on the minimum power requirement for the components. The power backup device then sets a second charging threshold that is higher than the first charging threshold and that is lower than a full charge level for the power backup device. In response to a charge level of the power backup device reaching the first charging threshold, the power backup device is charged, and in response to the charge level of the power backup device reaching the second charging threshold, the power backup device is prevented from charging.