If the AUX BAT light does not illuminate, what is the percentage of capacity for the auxiliary battery?

In aircraft systems, the illumination of the AUX BAT light serves as an indicator of the state of the auxiliary battery's capacity. If the light does not illuminate, it suggests that the battery is functioning properly and maintains a certain level of charge.

For the T-6A Texan II, if the AUX BAT light is not illuminated, it indicates that the battery is at or above 50% of its capacity. This is a critical detail to ensure that the aircraft can operate reliably without relying on the main battery or external power sources. A well-maintained auxiliary battery is crucial for powering essential systems and providing redundancy. Thus, the conclusion that the percentage of capacity for the auxiliary battery is at least 50% when the AUX BAT light does not illuminate aligns with the operational guidelines and indicators of the T-6A systems.