What happens when the standby instruments are powered by the auxiliary battery?

When the standby instruments are powered by the auxiliary battery, they operate in a limited capacity. This is due to the auxiliary battery's design, which is intended to provide enough power for essential flight instruments during a failure of the primary electrical system. The standby instruments display vital information needed for flying, such as altitude and airspeed, but they do not have the full functionality that they would when powered by the main electrical system. This limitation ensures that critical data is available, but it may not include all systems or readings that would be available under normal operating conditions. The auxiliary battery serves as a backup, ensuring safety, but it doesn't support the full range of capabilities normally offered.