Battery - Accurate, Low-Voltage Cutoff To Prevent Complete Battery Discharge 2018-05-29

Accessory usage when a vehicle's engine is stopped can excessively drain the battery and prevent an engine restart, thus it is desirable to have a circuit that can monitor the battery voltage and disconnect the accessories when a specific discharge level is reached.

Here is a circuit using a TL431 voltage reference IC as a comparator to turn off an accessory relay at the desired voltage.
In this application, the TL431 is not used as a voltage regulator, but acts as a comparator with a...

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