Car battery condition checker

Posted on Sep 19, 2012

This circuit uses an LED and 4081 CMOS integrated circuit. The variable resistor sets the voltage at which the LED turns on. Set the control so that the LED lights when the voltage from the car`s ignition switch drops below 13 volts

Car battery condition checker
Click here to download the full size of the above Circuit.

The LED normally will light every now and then for a short period of time. But, if it stays on for very long, your electrical system is in trouble.

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