The SharpZ3 system includes an auto shutdown feature to protect the vehicle battery and a cranking event protection feature which prevents a reboot due to a voltage dip caused by engine startup.
Auto shutdown
If the vehicle engine is off and the SharpZ3 system is running solely on vehicle battery power, the system shuts down after a 60 second delay (configurable) if battery voltage falls below 10.3 V at the base unit power connector. Note that there is an approximate 0.5 V to 0.7 V drop between the battery and the base unit power connector. For more information, see Configuring battery monitoring in the SharpOS 13.4 Sharp Portal.
Cranking event protection
Many law enforcement vehicles include external timers that maintain power to the equipment such as radios even when the engine is off. If the SharpZ3 system is being powered with an external timer, and the engine is then turned on, the resulting dip in voltage does not cause the SharpZ3 system to restart. The system can withstand a temporary voltage dip down to 7 V.